Spring Boot Reference Guide

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11/30/2018

Spring Boot Reference Guide

Spring Boot Reference Guide
Authors
Phillip Webb, Dave Syer, Josh Long, Stéphane Nicoll, Rob Winch, Andy Wilkinson, Marcel Overdijk, Christian Dupuis, Sébastien Deleuze, Michael
Simons, Vedran Pavić, Jay Bryant, Madhura Bhave

2.1.2.BUILD-SNAPSHOT

Copyright © 2012-2018
Copies of this document may be made for your own use and for distribution to others, provided that you do not charge any fee for such copies and further provided that
each copy contains this Copyright Notice, whether distributed in print or electronically.

Table of Contents

I. Spring Boot Documentation
1. About the Documentation
2. Getting Help
3. First Steps
4. Working with Spring Boot
5. Learning about Spring Boot Features
6. Moving to Production
7. Advanced Topics

II. Getting Started
8. Introducing Spring Boot
9. System Requirements
9.1. Servlet Containers

10. Installing Spring Boot
10.1. Installation Instructions for the Java Developer
10.1.1. Maven Installation
10.1.2. Gradle Installation

10.2. Installing the Spring Boot CLI
10.2.1. Manual Installation
10.2.2. Installation with SDKMAN!
10.2.3. OSX Homebrew Installation
10.2.4. MacPorts Installation
10.2.5. Command-line Completion
10.2.6. Windows Scoop Installation
10.2.7. Quick-start Spring CLI Example

10.3. Upgrading from an Earlier Version of Spring Boot

11. Developing Your First Spring Boot Application
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11.1. Creating the POM
11.2. Adding Classpath Dependencies
11.3. Writing the Code
11.3.1. The @RestController and @RequestMapping Annotations
11.3.2. The @EnableAutoConfiguration Annotation
11.3.3. The “main” Method

11.4. Running the Example
11.5. Creating an Executable Jar

12. What to Read Next

III. Using Spring Boot
13. Build Systems
13.1. Dependency Management
13.2. Maven
13.2.1. Inheriting the Starter Parent
13.2.2. Using Spring Boot without the Parent POM
13.2.3. Using the Spring Boot Maven Plugin

13.3. Gradle
13.4. Ant
13.5. Starters

14. Structuring Your Code
14.1. Using the “default” Package
14.2. Locating the Main Application Class

15. Configuration Classes
15.1. Importing Additional Configuration Classes
15.2. Importing XML Configuration

16. Auto-configuration
16.1. Gradually Replacing Auto-configuration
16.2. Disabling Specific Auto-configuration Classes

17. Spring Beans and Dependency Injection
18. Using the @SpringBootApplication Annotation
19. Running Your Application
19.1. Running from an IDE
19.2. Running as a Packaged Application
19.3. Using the Maven Plugin
19.4. Using the Gradle Plugin
19.5. Hot Swapping

20. Developer Tools
20.1. Property Defaults
20.2. Automatic Restart
20.2.1. Logging changes in condition evaluation
20.2.2. Excluding Resources
20.2.3. Watching Additional Paths
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20.2.4. Disabling Restart
20.2.5. Using a Trigger File
20.2.6. Customizing the Restart Classloader
20.2.7. Known Limitations

20.3. LiveReload
20.4. Global Settings
20.5. Remote Applications
20.5.1. Running the Remote Client Application
20.5.2. Remote Update

21. Packaging Your Application for Production
22. What to Read Next

IV. Spring Boot features
23. SpringApplication
23.1. Startup Failure
23.2. Customizing the Banner
23.3. Customizing SpringApplication
23.4. Fluent Builder API
23.5. Application Events and Listeners
23.6. Web Environment
23.7. Accessing Application Arguments
23.8. Using the ApplicationRunner or CommandLineRunner
23.9. Application Exit
23.10. Admin Features

24. Externalized Configuration
24.1. Configuring Random Values
24.2. Accessing Command Line Properties
24.3. Application Property Files
24.4. Profile-specific Properties
24.5. Placeholders in Properties
24.6. Encrypting Properties
24.7. Using YAML Instead of Properties
24.7.1. Loading YAML
24.7.2. Exposing YAML as Properties in the Spring Environment
24.7.3. Multi-profile YAML Documents
24.7.4. YAML Shortcomings

24.8. Type-safe Configuration Properties
24.8.1. Third-party Configuration
24.8.2. Relaxed Binding
24.8.3. Merging Complex Types
24.8.4. Properties Conversion
Converting durations
Converting Data Sizes
24.8.5. @ConfigurationProperties Validation
24.8.6. @ConfigurationProperties vs. @Value

25. Profiles
25.1. Adding Active Profiles
25.2. Programmatically Setting Profiles
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25.3. Profile-specific Configuration Files

26. Logging
26.1. Log Format
26.2. Console Output
26.2.1. Color-coded Output

26.3. File Output
26.4. Log Levels
26.5. Log Groups
26.6. Custom Log Configuration
26.7. Logback Extensions
26.7.1. Profile-specific Configuration
26.7.2. Environment Properties

27. JSON
27.1. Jackson
27.2. Gson
27.3. JSON-B

28. Developing Web Applications
28.1. The “Spring Web MVC Framework”
28.1.1. Spring MVC Auto-configuration
28.1.2. HttpMessageConverters
28.1.3. Custom JSON Serializers and Deserializers
28.1.4. MessageCodesResolver
28.1.5. Static Content
28.1.6. Welcome Page
28.1.7. Custom Favicon
28.1.8. Path Matching and Content Negotiation
28.1.9. ConfigurableWebBindingInitializer
28.1.10. Template Engines
28.1.11. Error Handling
Custom Error Pages
Mapping Error Pages outside of Spring MVC
28.1.12. Spring HATEOAS
28.1.13. CORS Support

28.2. The “Spring WebFlux Framework”
28.2.1. Spring WebFlux Auto-configuration
28.2.2. HTTP Codecs with HttpMessageReaders and HttpMessageWriters
28.2.3. Static Content
28.2.4. Template Engines
28.2.5. Error Handling
Custom Error Pages
28.2.6. Web Filters

28.3. JAX-RS and Jersey
28.4. Embedded Servlet Container Support
28.4.1. Servlets, Filters, and listeners
Registering Servlets, Filters, and Listeners as Spring Beans
28.4.2. Servlet Context Initialization
Scanning for Servlets, Filters, and listeners
28.4.3. The ServletWebServerApplicationContext
28.4.4. Customizing Embedded Servlet Containers
Programmatic Customization
Customizing ConfigurableServletWebServerFactory Directly
28.4.5. JSP Limitations

28.5. Embedded Reactive Server Support
28.6. Reactive Server Resources Configuration

29. Security
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29.1. MVC Security
29.2. WebFlux Security
29.3. OAuth2
29.3.1. Client
OAuth2 client registration for common providers
29.3.2. Resource Server
29.3.3. Authorization Server

29.4. Actuator Security
29.4.1. Cross Site Request Forgery Protection

30. Working with SQL Databases
30.1. Configure a DataSource
30.1.1. Embedded Database Support
30.1.2. Connection to a Production Database
30.1.3. Connection to a JNDI DataSource

30.2. Using JdbcTemplate
30.3. JPA and Spring Data JPA
30.3.1. Entity Classes
30.3.2. Spring Data JPA Repositories
30.3.3. Creating and Dropping JPA Databases
30.3.4. Open EntityManager in View

30.4. Spring Data JDBC
30.5. Using H2’s Web Console
30.5.1. Changing the H2 Console’s Path

30.6. Using jOOQ
30.6.1. Code Generation
30.6.2. Using DSLContext
30.6.3. jOOQ SQL Dialect
30.6.4. Customizing jOOQ

31. Working with NoSQL Technologies
31.1. Redis
31.1.1. Connecting to Redis

31.2. MongoDB
31.2.1. Connecting to a MongoDB Database
31.2.2. MongoTemplate
31.2.3. Spring Data MongoDB Repositories
31.2.4. Embedded Mongo

31.3. Neo4j
31.3.1. Connecting to a Neo4j Database
31.3.2. Using the Embedded Mode
31.3.3. Neo4jSession
31.3.4. Spring Data Neo4j Repositories

31.4. Gemfire
31.5. Solr
31.5.1. Connecting to Solr
31.5.2. Spring Data Solr Repositories

31.6. Elasticsearch
31.6.1. Connecting to Elasticsearch by REST clients
31.6.2. Connecting to Elasticsearch by Using Jest
31.6.3. Connecting to Elasticsearch by Using Spring Data
31.6.4. Spring Data Elasticsearch Repositories

31.7. Cassandra
31.7.1. Connecting to Cassandra
31.7.2. Spring Data Cassandra Repositories

31.8. Couchbase
31.8.1. Connecting to Couchbase
31.8.2. Spring Data Couchbase Repositories

31.9. LDAP
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31.9.1. Connecting to an LDAP Server
31.9.2. Spring Data LDAP Repositories
31.9.3. Embedded In-memory LDAP Server

31.10. InfluxDB
31.10.1. Connecting to InfluxDB

32. Caching
32.1. Supported Cache Providers
32.1.1. Generic
32.1.2. JCache (JSR-107)
32.1.3. EhCache 2.x
32.1.4. Hazelcast
32.1.5. Infinispan
32.1.6. Couchbase
32.1.7. Redis
32.1.8. Caffeine
32.1.9. Simple
32.1.10. None

33. Messaging
33.1. JMS
33.1.1. ActiveMQ Support
33.1.2. Artemis Support
33.1.3. Using a JNDI ConnectionFactory
33.1.4. Sending a Message
33.1.5. Receiving a Message

33.2. AMQP
33.2.1. RabbitMQ support
33.2.2. Sending a Message
33.2.3. Receiving a Message

33.3. Apache Kafka Support
33.3.1. Sending a Message
33.3.2. Receiving a Message
33.3.3. Kafka Streams
33.3.4. Additional Kafka Properties

34. Calling REST Services with

RestTemplate

34.1. RestTemplate Customization

35. Calling REST Services with

WebClient

35.1. WebClient Runtime
35.2. WebClient Customization

36. Validation
37. Sending Email
38. Distributed Transactions with JTA
38.1. Using an Atomikos Transaction Manager
38.2. Using a Bitronix Transaction Manager
38.3. Using a Java EE Managed Transaction Manager
38.4. Mixing XA and Non-XA JMS Connections
38.5. Supporting an Alternative Embedded Transaction Manager

39. Hazelcast
40. Quartz Scheduler
41. Task Execution and Scheduling
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42. Spring Integration
43. Spring Session
44. Monitoring and Management over JMX
45. Testing
45.1. Test Scope Dependencies
45.2. Testing Spring Applications
45.3. Testing Spring Boot Applications
45.3.1. Detecting Web Application Type
45.3.2. Detecting Test Configuration
45.3.3. Excluding Test Configuration
45.3.4. Testing with a mock environment
45.3.5. Testing with a running server
45.3.6. Using JMX
45.3.7. Mocking and Spying Beans
45.3.8. Auto-configured Tests
45.3.9. Auto-configured JSON Tests
45.3.10. Auto-configured Spring MVC Tests
45.3.11. Auto-configured Spring WebFlux Tests
45.3.12. Auto-configured Data JPA Tests
45.3.13. Auto-configured JDBC Tests
45.3.14. Auto-configured Data JDBC Tests
45.3.15. Auto-configured jOOQ Tests
45.3.16. Auto-configured Data MongoDB Tests
45.3.17. Auto-configured Data Neo4j Tests
45.3.18. Auto-configured Data Redis Tests
45.3.19. Auto-configured Data LDAP Tests
45.3.20. Auto-configured REST Clients
45.3.21. Auto-configured Spring REST Docs Tests
Auto-configured Spring REST Docs Tests with Mock MVC
Auto-configured Spring REST Docs Tests with REST Assured
45.3.22. Additional Auto-configuration and Slicing
45.3.23. User Configuration and Slicing
45.3.24. Using Spock to Test Spring Boot Applications

45.4. Test Utilities
45.4.1. ConfigFileApplicationContextInitializer
45.4.2. TestPropertyValues
45.4.3. OutputCapture
45.4.4. TestRestTemplate

46. WebSockets
47. Web Services
48. Calling Web Services with

WebServiceTemplate

49. Creating Your Own Auto-configuration
49.1. Understanding Auto-configured Beans
49.2. Locating Auto-configuration Candidates
49.3. Condition Annotations
49.3.1. Class Conditions
49.3.2. Bean Conditions
49.3.3. Property Conditions
49.3.4. Resource Conditions
49.3.5. Web Application Conditions
49.3.6. SpEL Expression Conditions

49.4. Testing your Auto-configuration
49.4.1. Simulating a Web Context
49.4.2. Overriding the Classpath

49.5. Creating Your Own Starter
49.5.1. Naming
49.5.2. autoconfigure Module
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49.5.3. Starter Module

50. Kotlin support
50.1. Requirements
50.2. Null-safety
50.3. Kotlin API
50.3.1. runApplication
50.3.2. Extensions

50.4. Dependency management
50.5. @ConfigurationProperties
50.6. Testing
50.7. Resources
50.7.1. Further reading
50.7.2. Examples

51. What to Read Next

V. Spring Boot Actuator: Production-ready features
52. Enabling Production-ready Features
53. Endpoints
53.1. Enabling Endpoints
53.2. Exposing Endpoints
53.3. Securing HTTP Endpoints
53.4. Configuring Endpoints
53.5. Hypermedia for Actuator Web Endpoints
53.6. CORS Support
53.7. Implementing Custom Endpoints
53.7.1. Receiving Input
Input type conversion
53.7.2. Custom Web Endpoints
Web Endpoint Request Predicates
Path
HTTP method
Consumes
Produces
Web Endpoint Response Status
Web Endpoint Range Requests
Web Endpoint Security
53.7.3. Servlet endpoints
53.7.4. Controller endpoints

53.8. Health Information
53.8.1. Auto-configured HealthIndicators
53.8.2. Writing Custom HealthIndicators
53.8.3. Reactive Health Indicators
53.8.4. Auto-configured ReactiveHealthIndicators

53.9. Application Information
53.9.1. Auto-configured InfoContributors
53.9.2. Custom Application Information
53.9.3. Git Commit Information
53.9.4. Build Information
53.9.5. Writing Custom InfoContributors

54. Monitoring and Management over HTTP
54.1. Customizing the Management Endpoint Paths
54.2. Customizing the Management Server Port
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54.3. Configuring Management-specific SSL
54.4. Customizing the Management Server Address
54.5. Disabling HTTP Endpoints

55. Monitoring and Management over JMX
55.1. Customizing MBean Names
55.2. Disabling JMX Endpoints
55.3. Using Jolokia for JMX over HTTP
55.3.1. Customizing Jolokia
55.3.2. Disabling Jolokia

56. Loggers
56.1. Configure a Logger

57. Metrics
57.1. Getting started
57.2. Supported monitoring systems
57.2.1. AppOptics
57.2.2. Atlas
57.2.3. Datadog
57.2.4. Dynatrace
57.2.5. Elastic
57.2.6. Ganglia
57.2.7. Graphite
57.2.8. Humio
57.2.9. Influx
57.2.10. JMX
57.2.11. KairosDB
57.2.12. New Relic
57.2.13. Prometheus
57.2.14. SignalFx
57.2.15. Simple
57.2.16. StatsD
57.2.17. Wavefront

57.3. Supported Metrics
57.3.1. Spring MVC Metrics
57.3.2. Spring WebFlux Metrics
57.3.3. Jersey Server Metrics
57.3.4. HTTP Client Metrics
57.3.5. Cache Metrics
57.3.6. DataSource Metrics
57.3.7. Hibernate Metrics
57.3.8. RabbitMQ Metrics

57.4. Registering custom metrics
57.5. Customizing individual metrics
57.5.1. Common tags
57.5.2. Per-meter properties

57.6. Metrics endpoint

58. Auditing
59. HTTP Tracing
59.1. Custom HTTP tracing

60. Process Monitoring
60.1. Extending Configuration
60.2. Programmatically

61. Cloud Foundry Support
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61.1. Disabling Extended Cloud Foundry Actuator Support
61.2. Cloud Foundry Self-signed Certificates
61.3. Custom context path

62. What to Read Next

VI. Deploying Spring Boot Applications
63. Deploying to the Cloud
63.1. Cloud Foundry
63.1.1. Binding to Services

63.2. Heroku
63.3. OpenShift
63.4. Amazon Web Services (AWS)
63.4.1. AWS Elastic Beanstalk
Using the Tomcat Platform
Using the Java SE Platform
63.4.2. Summary

63.5. Boxfuse and Amazon Web Services
63.6. Google Cloud

64. Installing Spring Boot Applications
64.1. Supported Operating Systems
64.2. Unix/Linux Services
64.2.1. Installation as an init.d Service (System V)
Securing an init.d Service
64.2.2. Installation as a systemd Service
64.2.3. Customizing the Startup Script
Customizing the Start Script when It Is Written
Customizing a Script When It Runs

64.3. Microsoft Windows Services

65. What to Read Next

VII. Spring Boot CLI
66. Installing the CLI
67. Using the CLI
67.1. Running Applications with the CLI
67.1.1. Deduced “grab” Dependencies
67.1.2. Deduced “grab” Coordinates
67.1.3. Default Import Statements
67.1.4. Automatic Main Method
67.1.5. Custom Dependency Management

67.2. Applications with Multiple Source Files
67.3. Packaging Your Application
67.4. Initialize a New Project
67.5. Using the Embedded Shell
67.6. Adding Extensions to the CLI

68. Developing Applications with the Groovy Beans DSL
69. Configuring the CLI with

settings.xml

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70. What to Read Next

VIII. Build tool plugins
71. Spring Boot Maven Plugin
71.1. Including the Plugin
71.2. Packaging Executable Jar and War Files

72. Spring Boot Gradle Plugin
73. Spring Boot AntLib Module
73.1. Spring Boot Ant Tasks
73.1.1. spring-boot:exejar
73.1.2. Examples

73.2. spring-boot:findmainclass
73.2.1. Examples

74. Supporting Other Build Systems
74.1. Repackaging Archives
74.2. Nested Libraries
74.3. Finding a Main Class
74.4. Example Repackage Implementation

75. What to Read Next

IX. ‘How-to’ guides
76. Spring Boot Application
76.1. Create Your Own FailureAnalyzer
76.2. Troubleshoot Auto-configuration
76.3. Customize the Environment or ApplicationContext Before It Starts
76.4. Build an ApplicationContext Hierarchy (Adding a Parent or Root Context)
76.5. Create a Non-web Application

77. Properties and Configuration
77.1. Automatically Expand Properties at Build Time
77.1.1. Automatic Property Expansion Using Maven
77.1.2. Automatic Property Expansion Using Gradle

77.2. Externalize the Configuration of SpringApplication
77.3. Change the Location of External Properties of an Application
77.4. Use ‘Short’ Command Line Arguments
77.5. Use YAML for External Properties
77.6. Set the Active Spring Profiles
77.7. Change Configuration Depending on the Environment
77.8. Discover Built-in Options for External Properties

78. Embedded Web Servers
78.1. Use Another Web Server
78.2. Disabling the Web Server
78.3. Change the HTTP Port
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78.4. Use a Random Unassigned HTTP Port
78.5. Discover the HTTP Port at Runtime
78.6. Enable HTTP Response Compression
78.7. Configure SSL
78.8. Configure HTTP/2
78.8.1. HTTP/2 with Undertow
78.8.2. HTTP/2 with Jetty
78.8.3. HTTP/2 with Tomcat
78.8.4. HTTP/2 with Reactor Netty

78.9. Configure the Web Server
78.10. Add a Servlet, Filter, or Listener to an Application
78.10.1. Add a Servlet, Filter, or Listener by Using a Spring Bean
Disable Registration of a Servlet or Filter
78.10.2. Add Servlets, Filters, and Listeners by Using Classpath Scanning

78.11. Configure Access Logging
78.12. Running Behind a Front-end Proxy Server
78.12.1. Customize Tomcat’s Proxy Configuration

78.13. Enable Multiple Connectors with Tomcat
78.14. Use Tomcat’s LegacyCookieProcessor
78.15. Enable Multiple Listeners with Undertow
78.16. Create WebSocket Endpoints Using @ServerEndpoint

79. Spring MVC
79.1. Write a JSON REST Service
79.2. Write an XML REST Service
79.3. Customize the Jackson ObjectMapper
79.4. Customize the @ResponseBody Rendering
79.5. Handling Multipart File Uploads
79.6. Switch Off the Spring MVC DispatcherServlet
79.7. Switch off the Default MVC Configuration
79.8. Customize ViewResolvers

80. Testing With Spring Security
81. Jersey
81.1. Secure Jersey endpoints with Spring Security

82. HTTP Clients
82.1. Configure RestTemplate to Use a Proxy

83. Logging
83.1. Configure Logback for Logging
83.1.1. Configure Logback for File-only Output

83.2. Configure Log4j for Logging
83.2.1. Use YAML or JSON to Configure Log4j 2

84. Data Access
84.1. Configure a Custom DataSource
84.2. Configure Two DataSources
84.3. Use Spring Data Repositories
84.4. Separate @Entity Definitions from Spring Configuration
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84.5. Configure JPA Properties
84.6. Configure Hibernate Naming Strategy
84.7. Configure Hibernate Second-Level Caching
84.8. Use Dependency Injection in Hibernate Components
84.9. Use a Custom EntityManagerFactory
84.10. Use Two EntityManagers
84.11. Use a Traditional persistence.xml File
84.12. Use Spring Data JPA and Mongo Repositories
84.13. Customize Spring Data’s Web Support
84.14. Expose Spring Data Repositories as REST Endpoint
84.15. Configure a Component that is Used by JPA
84.16. Configure jOOQ with Two DataSources

85. Database Initialization
85.1. Initialize a Database Using JPA
85.2. Initialize a Database Using Hibernate
85.3. Initialize a Database
85.4. Initialize a Spring Batch Database
85.5. Use a Higher-level Database Migration Tool
85.5.1. Execute Flyway Database Migrations on Startup
85.5.2. Execute Liquibase Database Migrations on Startup

86. Messaging
86.1. Disable Transacted JMS Session

87. Batch Applications
87.1. Execute Spring Batch Jobs on Startup

88. Actuator
88.1. Change the HTTP Port or Address of the Actuator Endpoints
88.2. Customize the ‘whitelabel’ Error Page
88.3. Sanitize sensible values

89. Security
89.1. Switch off the Spring Boot Security Configuration
89.2. Change the UserDetailsService and Add User Accounts
89.3. Enable HTTPS When Running behind a Proxy Server

90. Hot Swapping
90.1. Reload Static Content
90.2. Reload Templates without Restarting the Container
90.2.1. Thymeleaf Templates
90.2.2. FreeMarker Templates
90.2.3. Groovy Templates

90.3. Fast Application Restarts
90.4. Reload Java Classes without Restarting the Container

91. Build
91.1. Generate Build Information
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91.2. Generate Git Information
91.3. Customize Dependency Versions
91.4. Create an Executable JAR with Maven
91.5. Use a Spring Boot Application as a Dependency
91.6. Extract Specific Libraries When an Executable Jar Runs
91.7. Create a Non-executable JAR with Exclusions
91.8. Remote Debug a Spring Boot Application Started with Maven
91.9. Build an Executable Archive from Ant without Using spring-boot-antlib

92. Traditional Deployment
92.1. Create a Deployable War File
92.2. Convert an Existing Application to Spring Boot
92.3. Deploying a WAR to WebLogic
92.4. Use Jedis Instead of Lettuce

X. Appendices
A. Common application properties
B. Configuration Metadata
B.1. Metadata Format
B.1.1. Group Attributes
B.1.2. Property Attributes
B.1.3. Hint Attributes
B.1.4. Repeated Metadata Items

B.2. Providing Manual Hints
B.2.1. Value Hint
B.2.2. Value Providers
Any
Class Reference
Handle As
Logger Name
Spring Bean Reference
Spring Profile Name

B.3. Generating Your Own Metadata by Using the Annotation Processor
B.3.1. Nested Properties
B.3.2. Adding Additional Metadata

C. Auto-configuration classes
C.1. From the “spring-boot-autoconfigure” module
C.2. From the “spring-boot-actuator-autoconfigure” module

D. Test auto-configuration annotations
E. The Executable Jar Format
E.1. Nested JARs
E.1.1. The Executable Jar File Structure
E.1.2. The Executable War File Structure

E.2. Spring Boot’s “JarFile” Class
E.2.1. Compatibility with the Standard Java “JarFile”

E.3. Launching Executable Jars
E.3.1. Launcher Manifest
E.3.2. Exploded Archives

E.4. PropertiesLauncher Features
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E.5. Executable Jar Restrictions
E.6. Alternative Single Jar Solutions

F. Dependency versions

Part I. Spring Boot Documentation
This section provides a brief overview of Spring Boot reference documentation. It serves as a map for the rest of the document.

1. About the Documentation
The Spring Boot reference guide is available as
HTML
PDF
EPUB
The latest copy is available at docs.spring.io/spring-boot/docs/current/reference.
Copies of this document may be made for your own use and for distribution to others, provided that you do not charge any fee for such copies and
further provided that each copy contains this Copyright Notice, whether distributed in print or electronically.

2. Getting Help
If you have trouble with Spring Boot, we would like to help.
Try the How-to documents. They provide solutions to the most common questions.
Learn the Spring basics. Spring Boot builds on many other Spring projects. Check the spring.io web-site for a wealth of reference
documentation. If you are starting out with Spring, try one of the guides.
Ask a question. We monitor stackoverflow.com for questions tagged with spring-boot .
Report bugs with Spring Boot at github.com/spring-projects/spring-boot/issues.

All of Spring Boot is open source, including the documentation. If you find problems with the docs or if you want to improve them,
please get involved.

3. First Steps
If you are getting started with Spring Boot or 'Spring' in general, start with the following topics:
From scratch: Overview | Requirements | Installation
Tutorial: Part 1 | Part 2
Running your example: Part 1 | Part 2

4. Working with Spring Boot
Ready to actually start using Spring Boot? We have you covered:
Build systems: Maven | Gradle | Ant | Starters
Best practices: Code Structure | @Configuration | @EnableAutoConfiguration | Beans and Dependency Injection
Running your code IDE | Packaged | Maven | Gradle
Packaging your app: Production jars
Spring Boot CLI: Using the CLI

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5. Learning about Spring Boot Features
Need more details about Spring Boot’s core features? The following content is for you:
Core Features: SpringApplication | External Configuration | Profiles | Logging
Web Applications: MVC | Embedded Containers
Working with data: SQL | NO-SQL
Messaging: Overview | JMS
Testing: Overview | Boot Applications | Utils
Extending: Auto-configuration | @Conditions

6. Moving to Production
When you are ready to push your Spring Boot application to production, we have some tricks that you might like:
Management endpoints: Overview | Customization
Connection options: HTTP | JMX
Monitoring: Metrics | Auditing | Tracing | Process

7. Advanced Topics
Finally, we have a few topics for more advanced users:
Spring Boot Applications Deployment: Cloud Deployment | OS Service
Build tool plugins: Maven | Gradle
Appendix: Application Properties | Auto-configuration classes | Executable Jars

Part II. Getting Started
If you are getting started with Spring Boot, or “Spring” in general, start by reading this section. It answers the basic “what?”, “how?” and “why?”
questions. It includes an introduction to Spring Boot, along with installation instructions. We then walk you through building your first Spring Boot
application, discussing some core principles as we go.

8. Introducing Spring Boot
Spring Boot makes it easy to create stand-alone, production-grade Spring-based Applications that you can run. We take an opinionated view of the
Spring platform and third-party libraries, so that you can get started with minimum fuss. Most Spring Boot applications need very little Spring
configuration.
You can use Spring Boot to create Java applications that can be started by using java -jar or more traditional war deployments. We also provide
a command line tool that runs “spring scripts”.
Our primary goals are:
Provide a radically faster and widely accessible getting-started experience for all Spring development.
Be opinionated out of the box but get out of the way quickly as requirements start to diverge from the defaults.
Provide a range of non-functional features that are common to large classes of projects (such as embedded servers, security, metrics, health
checks, and externalized configuration).
Absolutely no code generation and no requirement for XML configuration.

9. System Requirements
Spring Boot 2.1.2.BUILD-SNAPSHOT requires Java 8 and is compatible up to Java 11 (included). Spring Framework 5.1.3.RELEASE or above is
also required.

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Explicit build support is provided for the following build tools:
Build Tool

Version

Maven

3.3+

Gradle

4.4+

9.1 Servlet Containers
Spring Boot supports the following embedded servlet containers:
Name

Servlet Version

Tomcat 9.0

4.0

Jetty 9.4

3.1

Undertow 2.0

4.0

You can also deploy Spring Boot applications to any Servlet 3.1+ compatible container.

10. Installing Spring Boot
Spring Boot can be used with “classic” Java development tools or installed as a command line tool. Either way, you need Java SDK v1.8 or higher.
Before you begin, you should check your current Java installation by using the following command:
$ java -version

If you are new to Java development or if you want to experiment with Spring Boot, you might want to try the Spring Boot CLI (Command Line
Interface) first. Otherwise, read on for “classic” installation instructions.

10.1 Installation Instructions for the Java Developer
You can use Spring Boot in the same way as any standard Java library. To do so, include the appropriate spring-boot-*.jar files on your
classpath. Spring Boot does not require any special tools integration, so you can use any IDE or text editor. Also, there is nothing special about a
Spring Boot application, so you can run and debug a Spring Boot application as you would any other Java program.
Although you could copy Spring Boot jars, we generally recommend that you use a build tool that supports dependency management (such as
Maven or Gradle).

10.1.1 Maven Installation
Spring Boot is compatible with Apache Maven 3.3 or above. If you do not already have Maven installed, you can follow the instructions at
maven.apache.org.

On many operating systems, Maven can be installed with a package manager. If you use OSX Homebrew, try brew install maven .
Ubuntu users can run sudo apt-get install maven . Windows users with Chocolatey can run choco install maven from an
elevated (administrator) prompt.

Spring Boot dependencies use the org.springframework.boot groupId . Typically, your Maven POM file inherits from the
spring-boot-starter-parent project and declares dependencies to one or more “Starters”. Spring Boot also provides an optional Maven plugin
to create executable jars.
The following listing shows a typical pom.xml file:

j t
l
"htt //
h
/POM/4 0 0"

l

i "htt

//

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3

/2001/XMLS h

i

t

"

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4.0.0
com.example
myproject
0.0.1-SNAPSHOT


org.springframework.boot
spring-boot-starter-parent
2.1.2.BUILD-SNAPSHOT




org.springframework.boot
spring-boot-starter-web






org.springframework.boot
spring-boot-maven-plugin







spring-snapshots
https://repo.spring.io/snapshot
true


spring-milestones
https://repo.spring.io/milestone




spring-snapshots
https://repo.spring.io/snapshot


spring-milestones
https://repo.spring.io/milestone




The spring-boot-starter-parent is a great way to use Spring Boot, but it might not be suitable all of the time. Sometimes you
may need to inherit from a different parent POM, or you might not like our default settings. In those cases, see Section 13.2.2, “Using
Spring Boot without the Parent POM” for an alternative solution that uses an import scope.

10.1.2 Gradle Installation
Spring Boot is compatible with Gradle 4.4 and later. If you do not already have Gradle installed, you can follow the instructions at gradle.org.
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Spring Boot dependencies can be declared by using the org.springframework.boot group . Typically, your project declares dependencies to
one or more “Starters”. Spring Boot provides a useful Gradle plugin that can be used to simplify dependency declarations and to create executable
jars.
Gradle Wrapper
The Gradle Wrapper provides a nice way of “obtaining” Gradle when you need to build a project. It is a small script and library that you commit
alongside your code to bootstrap the build process. See docs.gradle.org/4.2.1/userguide/gradle_wrapper.html for details.
More details on getting started with Spring Boot and Gradle can be found in the Getting Started section of the Gradle plugin’s reference guide.

10.2 Installing the Spring Boot CLI
The Spring Boot CLI (Command Line Interface) is a command line tool that you can use to quickly prototype with Spring. It lets you run Groovy
scripts, which means that you have a familiar Java-like syntax without so much boilerplate code.
You do not need to use the CLI to work with Spring Boot, but it is definitely the quickest way to get a Spring application off the ground.

10.2.1 Manual Installation
You can download the Spring CLI distribution from the Spring software repository:
spring-boot-cli-2.1.2.BUILD-SNAPSHOT-bin.zip
spring-boot-cli-2.1.2.BUILD-SNAPSHOT-bin.tar.gz
Cutting edge snapshot distributions are also available.
Once downloaded, follow the INSTALL.txt instructions from the unpacked archive. In summary, there is a spring script ( spring.bat for
Windows) in a bin/ directory in the .zip file. Alternatively, you can use java -jar with the .jar file (the script helps you to be sure that the
classpath is set correctly).

10.2.2 Installation with SDKMAN!
SDKMAN! (The Software Development Kit Manager) can be used for managing multiple versions of various binary SDKs, including Groovy and the
Spring Boot CLI. Get SDKMAN! from sdkman.io and install Spring Boot by using the following commands:
$ sdk install springboot
$ spring --version
Spring Boot v2.1.2.BUILD-SNAPSHOT

If you develop features for the CLI and want easy access to the version you built, use the following commands:
$ sdk install springboot dev /path/to/spring-boot/spring-boot-cli/target/spring-boot-cli-2.1.2.BUILD-SNAPSHOT-bin/spring-2.1.2
$ sdk default springboot dev
$ spring --version
Spring CLI v2.1.2.BUILD-SNAPSHOT

The preceding instructions install a local instance of spring called the dev instance. It points at your target build location, so every time you
rebuild Spring Boot, spring is up-to-date.
You can see it by running the following command:
$ sdk ls springboot
================================================================================
Available Springboot Versions
================================================================================
> + dev
* 2.1.2.BUILD-SNAPSHOT
================================================================================
+ - local version
* - installed

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installed
> - currently in use
================================================================================

10.2.3 OSX Homebrew Installation
If you are on a Mac and use Homebrew, you can install the Spring Boot CLI by using the following commands:
$ brew tap pivotal/tap
$ brew install springboot

Homebrew installs spring to /usr/local/bin .

If you do not see the formula, your installation of brew might be out-of-date. In that case, run brew update and try again.

10.2.4 MacPorts Installation
If you are on a Mac and use MacPorts, you can install the Spring Boot CLI by using the following command:
$ sudo port install spring-boot-cli

10.2.5 Command-line Completion
The Spring Boot CLI includes scripts that provide command completion for the BASH and zsh shells. You can source the script (also named
spring ) in any shell or put it in your personal or system-wide bash completion initialization. On a Debian system, the system-wide scripts are in
/shell-completion/bash and all scripts in that directory are executed when a new shell starts. For example, to run the script manually if you
have installed by using SDKMAN!, use the following commands:
$ . ~/.sdkman/candidates/springboot/current/shell-completion/bash/spring
$ spring 
grab help jar run test version

If you install the Spring Boot CLI by using Homebrew or MacPorts, the command-line completion scripts are automatically registered
with your shell.

10.2.6 Windows Scoop Installation
If you are on a Windows and use Scoop, you can install the Spring Boot CLI by using the following commands:
> scoop bucket add extras
> scoop install springboot

Scoop installs spring to ~/scoop/apps/springboot/current/bin .

If you do not see the app manifest, your installation of scoop might be out-of-date. In that case, run scoop update and try again.

10.2.7 Quick-start Spring CLI Example
You can use the following web application to test your installation. To start, create a file called app.groovy , as follows:
@RestController
class ThisWillActuallyRun {
@RequestMapping("/")
String home() {
"Hello World!"
}

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}

Then run it from a shell, as follows:
$ spring run app.groovy

The first run of your application is slow, as dependencies are downloaded. Subsequent runs are much quicker.

Open localhost:8080 in your favorite web browser. You should see the following output:
Hello World!

10.3 Upgrading from an Earlier Version of Spring Boot
If you are upgrading from an earlier release of Spring Boot, check the “migration guide” on the project wiki that provides detailed upgrade
instructions. Check also the “release notes” for a list of “new and noteworthy” features for each release.
When upgrading to a new feature release, some properties may have been renamed or removed. Spring Boot provides a way to analyze your
application’s environment and print diagnostics at startup, but also temporarily migrate properties at runtime for you. To enable that feature, add the
following dependency to your project:

org.springframework.boot
spring-boot-properties-migrator
runtime


Properties that are added late to the environment, such as when using @PropertySource , will not be taken into account.

Once you’re done with the migration, please make sure to remove this module from your project’s dependencies.

To upgrade an existing CLI installation, use the appropriate package manager command (for example, brew upgrade ) or, if you manually installed
the CLI, follow the standard instructions, remembering to update your PATH environment variable to remove any older references.

11. Developing Your First Spring Boot Application
This section describes how to develop a simple “Hello World!” web application that highlights some of Spring Boot’s key features. We use Maven to
build this project, since most IDEs support it.

The spring.io web site contains many “Getting Started” guides that use Spring Boot. If you need to solve a specific problem, check
there first.
You can shortcut the steps below by going to start.spring.io and choosing the "Web" starter from the dependencies searcher. Doing so
generates a new project structure so that you can start coding right away. Check the Spring Initializr documentation for more details.

Before we begin, open a terminal and run the following commands to ensure that you have valid versions of Java and Maven installed:
$ java -version
java version "1.8.0_102"
Java(TM) SE Runtime Environment (build 1.8.0_102-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.102-b14, mixed mode)
$ mvn -v
Apache Maven 3.5.4 (1edded0938998edf8bf061f1ceb3cfdeccf443fe; 2018-06-17T14:33:14-04:00)
Maven home: /usr/local/Cellar/maven/3.3.9/libexec
Java version: 1.8.0_102, vendor: Oracle Corporation

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This sample needs to be created in its own folder. Subsequent instructions assume that you have created a suitable folder and that it
is your current directory.

11.1 Creating the POM
We need to start by creating a Maven pom.xml file. The pom.xml is the recipe that is used to build your project. Open your favorite text editor and
add the following:


4.0.0
com.example
myproject
0.0.1-SNAPSHOT

org.springframework.boot
spring-boot-starter-parent
2.1.2.BUILD-SNAPSHOT





spring-snapshots
https://repo.spring.io/snapshot
true


spring-milestones
https://repo.spring.io/milestone




spring-snapshots
https://repo.spring.io/snapshot


spring-milestones
https://repo.spring.io/milestone




The preceding listing should give you a working build. You can test it by running mvn package (for now, you can ignore the “jar will be empty - no
content was marked for inclusion!” warning).

At this point, you could import the project into an IDE (most modern Java IDEs include built-in support for Maven). For simplicity, we
continue to use a plain text editor for this example.

11.2 Adding Classpath Dependencies
Spring Boot provides a number of “Starters” that let you add jars to your classpath. Our sample application has already used
spring-boot-starter-parent in the parent section of the POM. The spring-boot-starter-parent is a special starter that provides useful
Maven defaults. It also provides a dependency-management section so that you can omit version tags for “blessed” dependencies.

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Other “Starters” provide dependencies that you are likely to need when developing a specific type of application. Since we are developing a web
application, we add a spring-boot-starter-web dependency. Before that, we can look at what we currently have by running the following
command:
$ mvn dependency:tree
[INFO] com.example:myproject:jar:0.0.1-SNAPSHOT

The mvn dependency:tree command prints a tree representation of your project dependencies. You can see that
spring-boot-starter-parent provides no dependencies by itself. To add the necessary dependencies, edit your pom.xml and add the
spring-boot-starter-web dependency immediately below the parent section:


org.springframework.boot
spring-boot-starter-web



If you run mvn dependency:tree again, you see that there are now a number of additional dependencies, including the Tomcat web server and
Spring Boot itself.

11.3 Writing the Code
To finish our application, we need to create a single Java file. By default, Maven compiles sources from src/main/java , so you need to create that
folder structure and then add a file named src/main/java/Example.java to contain the following code:
import org.springframework.boot.*;
import org.springframework.boot.autoconfigure.*;
import org.springframework.web.bind.annotation.*;
@RestController
@EnableAutoConfiguration
public class Example {
@RequestMapping("/")
String home() {
return "Hello World!";
}
public static void main(String[] args) throws Exception {
SpringApplication.run(Example.class, args);
}
}

Although there is not much code here, quite a lot is going on. We step through the important parts in the next few sections.

11.3.1 The @RestController and @RequestMapping Annotations
The first annotation on our Example class is @RestController . This is known as a stereotype annotation. It provides hints for people reading the
code and for Spring that the class plays a specific role. In this case, our class is a web @Controller , so Spring considers it when handling
incoming web requests.
The @RequestMapping annotation provides “routing” information. It tells Spring that any HTTP request with the / path should be mapped to the
home method. The @RestController annotation tells Spring to render the resulting string directly back to the caller.

The @RestController and @RequestMapping annotations are Spring MVC annotations. (They are not specific to Spring Boot.) See
the MVC section in the Spring Reference Documentation for more details.

11.3.2 The @EnableAutoConfiguration Annotation
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The second class-level annotation is @EnableAutoConfiguration . This annotation tells Spring Boot to “guess” how you want to configure Spring,
based on the jar dependencies that you have added. Since spring-boot-starter-web added Tomcat and Spring MVC, the auto-configuration
assumes that you are developing a web application and sets up Spring accordingly.
Starters and Auto-configuration
Auto-configuration is designed to work well with “Starters”, but the two concepts are not directly tied. You are free to pick and choose jar
dependencies outside of the starters. Spring Boot still does its best to auto-configure your application.

11.3.3 The “main” Method
The final part of our application is the main method. This is just a standard method that follows the Java convention for an application entry point.
Our main method delegates to Spring Boot’s SpringApplication class by calling run . SpringApplication bootstraps our application, starting
Spring, which, in turn, starts the auto-configured Tomcat web server. We need to pass Example.class as an argument to the run method to tell
SpringApplication which is the primary Spring component. The args array is also passed through to expose any command-line arguments.

11.4 Running the Example
At this point, your application should work. Since you used the spring-boot-starter-parent POM, you have a useful run goal that you can
use to start the application. Type mvn spring-boot:run from the root project directory to start the application. You should see output similar to the
following:
$ mvn spring-boot:run
.
____
_
__ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.1.2.BUILD-SNAPSHOT)
....... . . .
....... . . . (log output here)
....... . . .
........ Started Example in 2.222 seconds (JVM running for 6.514)

If you open a web browser to localhost:8080 , you should see the following output:
Hello World!

To gracefully exit the application, press ctrl-c .

11.5 Creating an Executable Jar
We finish our example by creating a completely self-contained executable jar file that we could run in production. Executable jars (sometimes called
“fat jars”) are archives containing your compiled classes along with all of the jar dependencies that your code needs to run.
Executable jars and Java
Java does not provide a standard way to load nested jar files (jar files that are themselves contained within a jar). This can be problematic if
you are looking to distribute a self-contained application.
To solve this problem, many developers use “uber” jars. An uber jar packages all the classes from all the application’s dependencies into a
single archive. The problem with this approach is that it becomes hard to see which libraries are in your application. It can also be problematic
if the same filename is used (but with different content) in multiple jars.
Spring Boot takes a different approach and lets you actually nest jars directly.
To create an executable jar, we need to add the spring-boot-maven-plugin to our pom.xml . To do so, insert the following lines just below the
dependencies section:

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org.springframework.boot
spring-boot-maven-plugin




The spring-boot-starter-parent POM includes  configuration to bind the repackage goal. If you do not use the
parent POM, you need to declare this configuration yourself. See the plugin documentation for details.

Save your pom.xml and run mvn package from the command line, as follows:
$ mvn package
[INFO]
[INFO]
[INFO]
[INFO]
[INFO]
[INFO]
[INFO]
[INFO]
[INFO]
[INFO]
[INFO]
[INFO]
[INFO]

Scanning for projects...
-----------------------------------------------------------------------Building myproject 0.0.1-SNAPSHOT
-----------------------------------------------------------------------.... ..
--- maven-jar-plugin:2.4:jar (default-jar) @ myproject --Building jar: /Users/developer/example/spring-boot-example/target/myproject-0.0.1-SNAPSHOT.jar
--- spring-boot-maven-plugin:2.1.2.BUILD-SNAPSHOT:repackage (default) @ myproject -------------------------------------------------------------------------BUILD SUCCESS
------------------------------------------------------------------------

If you look in the target directory, you should see myproject-0.0.1-SNAPSHOT.jar . The file should be around 10 MB in size. If you want to
peek inside, you can use jar tvf , as follows:
$ jar tvf target/myproject-0.0.1-SNAPSHOT.jar

You should also see a much smaller file named myproject-0.0.1-SNAPSHOT.jar.original in the target directory. This is the original jar file
that Maven created before it was repackaged by Spring Boot.
To run that application, use the java -jar command, as follows:
$ java -jar target/myproject-0.0.1-SNAPSHOT.jar
.
____
_
__ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.1.2.BUILD-SNAPSHOT)
....... . . .
....... . . . (log output here)
....... . . .
........ Started Example in 2.536 seconds (JVM running for 2.864)

As before, to exit the application, press ctrl-c .

12. What to Read Next
Hopefully, this section provided some of the Spring Boot basics and got you on your way to writing your own applications. If you are a task-oriented
type of developer, you might want to jump over to spring.io and check out some of the getting started guides that solve specific “How do I do that
with Spring?” problems. We also have Spring Boot-specific “How-to” reference documentation.
The Spring Boot repository also has a bunch of samples you can run. The samples are independent of the rest of the code (that is, you do not need
to build the rest to run or use the samples).
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Otherwise, the next logical step is to read Part III, “Using Spring Boot”. If you are really impatient, you could also jump ahead and read about Spring
Boot features.

Part III. Using Spring Boot
This section goes into more detail about how you should use Spring Boot. It covers topics such as build systems, auto-configuration, and how to run
your applications. We also cover some Spring Boot best practices. Although there is nothing particularly special about Spring Boot (it is just another
library that you can consume), there are a few recommendations that, when followed, make your development process a little easier.
If you are starting out with Spring Boot, you should probably read the Getting Started guide before diving into this section.

13. Build Systems
It is strongly recommended that you choose a build system that supports dependency management and that can consume artifacts published to the
“Maven Central” repository. We would recommend that you choose Maven or Gradle. It is possible to get Spring Boot to work with other build
systems (Ant, for example), but they are not particularly well supported.

13.1 Dependency Management
Each release of Spring Boot provides a curated list of dependencies that it supports. In practice, you do not need to provide a version for any of
these dependencies in your build configuration, as Spring Boot manages that for you. When you upgrade Spring Boot itself, these dependencies are
upgraded as well in a consistent way.

You can still specify a version and override Spring Boot’s recommendations if you need to do so.

The curated list contains all the spring modules that you can use with Spring Boot as well as a refined list of third party libraries. The list is available
as a standard Bills of Materials ( spring-boot-dependencies ) that can be used with both Maven and Gradle.

Each release of Spring Boot is associated with a base version of the Spring Framework. We highly recommend that you not specify
its version.

13.2 Maven
Maven users can inherit from the spring-boot-starter-parent project to obtain sensible defaults. The parent project provides the following
features:
Java 1.8 as the default compiler level.
UTF-8 source encoding.
A Dependency Management section, inherited from the spring-boot-dependencies pom, that manages the versions of common dependencies.
This dependency management lets you omit  tags for those dependencies when used in your own pom.
An execution of the repackage goal with a repackage execution id.
Sensible resource filtering.
Sensible plugin configuration (exec plugin, Git commit ID, and shade).
Sensible resource filtering for application.properties and application.yml including profile-specific files (for example,
application-dev.properties and application-dev.yml )
Note that, since the application.properties and application.yml files accept Spring style placeholders ( ${…} ), the Maven filtering is
changed to use @..@ placeholders. (You can override that by setting a Maven property called resource.delimiter .)

13.2.1 Inheriting the Starter Parent
To configure your project to inherit from the spring-boot-starter-parent , set the parent as follows:
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org.springframework.boot
spring-boot-starter-parent
2.1.2.BUILD-SNAPSHOT


You should need to specify only the Spring Boot version number on this dependency. If you import additional starters, you can safely
omit the version number.

With that setup, you can also override individual dependencies by overriding a property in your own project. For instance, to upgrade to another
Spring Data release train, you would add the following to your pom.xml :

Fowler-SR2


Check the spring-boot-dependencies pom for a list of supported properties.

13.2.2 Using Spring Boot without the Parent POM
Not everyone likes inheriting from the spring-boot-starter-parent POM. You may have your own corporate standard parent that you need to
use or you may prefer to explicitly declare all your Maven configuration.
If you do not want to use the spring-boot-starter-parent , you can still keep the benefit of the dependency management (but not the plugin
management) by using a scope=import dependency, as follows:




org.springframework.boot
spring-boot-dependencies
2.1.2.BUILD-SNAPSHOT
pom
import




The preceding sample setup does not let you override individual dependencies by using a property, as explained above. To achieve the same result,
you need to add an entry in the dependencyManagement of your project before the spring-boot-dependencies entry. For instance, to upgrade
to another Spring Data release train, you could add the following element to your pom.xml :




org.springframework.data
spring-data-releasetrain
Fowler-SR2
pom
import


org.springframework.boot
spring-boot-dependencies
2.1.2.BUILD-SNAPSHOT
pom
import




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In the preceding example, we specify a BOM, but any dependency type can be overridden in the same way.

13.2.3 Using the Spring Boot Maven Plugin
Spring Boot includes a Maven plugin that can package the project as an executable jar. Add the plugin to your  section if you want to
use it, as shown in the following example:



org.springframework.boot
spring-boot-maven-plugin




If you use the Spring Boot starter parent pom, you need to add only the plugin. There is no need to configure it unless you want to
change the settings defined in the parent.

13.3 Gradle
To learn about using Spring Boot with Gradle, please refer to the documentation for Spring Boot’s Gradle plugin:
Reference (HTML and PDF)
API

13.4 Ant
It is possible to build a Spring Boot project using Apache Ant+Ivy. The spring-boot-antlib “AntLib” module is also available to help Ant create
executable jars.
To declare dependencies, a typical ivy.xml file looks something like the following example:











A typical build.xml looks like the following example:








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If you do not want to use the spring-boot-antlib module, see the Section 91.9, “Build an Executable Archive from Ant without
Using spring-boot-antlib ” “How-to” .

13.5 Starters
Starters are a set of convenient dependency descriptors that you can include in your application. You get a one-stop shop for all the Spring and
related technologies that you need without having to hunt through sample code and copy-paste loads of dependency descriptors. For example, if
you want to get started using Spring and JPA for database access, include the spring-boot-starter-data-jpa dependency in your project.
The starters contain a lot of the dependencies that you need to get a project up and running quickly and with a consistent, supported set of managed
transitive dependencies.
What’s in a name
All official starters follow a similar naming pattern; spring-boot-starter-* , where * is a particular type of application. This naming
structure is intended to help when you need to find a starter. The Maven integration in many IDEs lets you search dependencies by name. For
example, with the appropriate Eclipse or STS plugin installed, you can press ctrl-space in the POM editor and type “spring-boot-starter” for
a complete list.
As explained in the “Creating Your Own Starter” section, third party starters should not start with spring-boot , as it is reserved for official
Spring Boot artifacts. Rather, a third-party starter typically starts with the name of the project. For example, a third-party starter project called
thirdpartyproject would typically be named thirdpartyproject-spring-boot-starter .
The following application starters are provided by Spring Boot under the org.springframework.boot group:

Table 13.1. Spring Boot application starters
Name

Description

Pom

spring-boot-starter

Core starter, including auto-configuration support, logging and YAML

Pom

spring-boot-starter-activemq

Starter for JMS messaging using Apache ActiveMQ

Pom

spring-boot-starter-amqp

Starter for using Spring AMQP and Rabbit MQ

Pom

spring-boot-starter-aop

Starter for aspect-oriented programming with Spring AOP and AspectJ

Pom

spring-boot-starter-artemis

Starter for JMS messaging using Apache Artemis

Pom

spring-boot-starter-batch

Starter for using Spring Batch

Pom

spring-boot-starter-cache

Starter for using Spring Framework’s caching support

Pom

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Description
Starter for using Spring Cloud Connectors which simplifies connecting to

Pom
Pom

services in cloud platforms like Cloud Foundry and Heroku
spring-boot-starter-data-cassandra

Starter for using Cassandra distributed database and Spring Data

Pom

Cassandra
spring-boot-starter-data-cassandra-reactive

Starter for using Cassandra distributed database and Spring Data

Pom

Cassandra Reactive
spring-boot-starter-data-couchbase

Starter for using Couchbase document-oriented database and Spring

Pom

Data Couchbase
spring-boot-starter-data-couchbase-reactive

Starter for using Couchbase document-oriented database and Spring

Pom

Data Couchbase Reactive
spring-boot-starter-data-elasticsearch

Starter for using Elasticsearch search and analytics engine and Spring

Pom

Data Elasticsearch
spring-boot-starter-data-jdbc

Starter for using Spring Data JDBC

Pom

spring-boot-starter-data-jpa

Starter for using Spring Data JPA with Hibernate

Pom

spring-boot-starter-data-ldap

Starter for using Spring Data LDAP

Pom

spring-boot-starter-data-mongodb

Starter for using MongoDB document-oriented database and Spring Data

Pom

MongoDB
spring-boot-starter-data-mongodb-reactive

Starter for using MongoDB document-oriented database and Spring Data

Pom

MongoDB Reactive
spring-boot-starter-data-neo4j

Starter for using Neo4j graph database and Spring Data Neo4j

Pom

spring-boot-starter-data-redis

Starter for using Redis key-value data store with Spring Data Redis and

Pom

the Lettuce client
spring-boot-starter-data-redis-reactive

Starter for using Redis key-value data store with Spring Data Redis

Pom

reactive and the Lettuce client
spring-boot-starter-data-rest

Starter for exposing Spring Data repositories over REST using Spring

Pom

Data REST
spring-boot-starter-data-solr

Starter for using the Apache Solr search platform with Spring Data Solr

Pom

spring-boot-starter-freemarker

Starter for building MVC web applications using FreeMarker views

Pom

spring-boot-starter-groovy-templates

Starter for building MVC web applications using Groovy Templates views

Pom

spring-boot-starter-hateoas

Starter for building hypermedia-based RESTful web application with

Pom

Spring MVC and Spring HATEOAS
spring-boot-starter-integration

Starter for using Spring Integration

Pom

spring-boot-starter-jdbc

Starter for using JDBC with the HikariCP connection pool

Pom

spring-boot-starter-jersey

Starter for building RESTful web applications using JAX-RS and Jersey.

Pom

An alternative to spring-boot-starter-web
spring-boot-starter-jooq

Starter for using jOOQ to access SQL databases. An alternative to

Pom

spring-boot-starter-data-jpa or spring-boot-starter-jdbc
spring-boot-starter-json

Starter for reading and writing json

Pom

spring-boot-starter-jta-atomikos

Starter for JTA transactions using Atomikos

Pom

spring-boot-starter-jta-bitronix

Starter for JTA transactions using Bitronix

Pom

spring-boot-starter-mail

Starter for using Java Mail and Spring Framework’s email sending

Pom

support
spring-boot-starter-mustache

Starter for building web applications using Mustache views

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Name

Description

spring-boot-starter-oauth2-client

Starter for using Spring Security’s OAuth2/OpenID Connect client

Pom
Pom

features
spring-boot-starter-oauth2-resource-server

Starter for using Spring Security’s OAuth2 resource server features

Pom

spring-boot-starter-quartz

Starter for using the Quartz scheduler

Pom

spring-boot-starter-security

Starter for using Spring Security

Pom

spring-boot-starter-test

Starter for testing Spring Boot applications with libraries including JUnit,

Pom

Hamcrest and Mockito
spring-boot-starter-thymeleaf

Starter for building MVC web applications using Thymeleaf views

Pom

spring-boot-starter-validation

Starter for using Java Bean Validation with Hibernate Validator

Pom

spring-boot-starter-web

Starter for building web, including RESTful, applications using Spring

Pom

MVC. Uses Tomcat as the default embedded container
spring-boot-starter-web-services

Starter for using Spring Web Services

Pom

spring-boot-starter-webflux

Starter for building WebFlux applications using Spring Framework’s

Pom

Reactive Web support
spring-boot-starter-websocket

Starter for building WebSocket applications using Spring Framework’s

Pom

WebSocket support

In addition to the application starters, the following starters can be used to add production ready features:

Table 13.2. Spring Boot production starters
Name
spring-boot-starter-actuator

Description
Starter for using Spring Boot’s Actuator which provides production ready features to help

Pom
Pom

you monitor and manage your application

Finally, Spring Boot also includes the following starters that can be used if you want to exclude or swap specific technical facets:

Table 13.3. Spring Boot technical starters
Name
spring-boot-starter-jetty

Description
Starter for using Jetty as the embedded servlet container. An alternative to

Pom
Pom

spring-boot-starter-tomcat
spring-boot-starter-log4j2

Starter for using Log4j2 for logging. An alternative to

Pom

spring-boot-starter-logging
spring-boot-starter-logging

Starter for logging using Logback. Default logging starter

Pom

spring-boot-starter-reactor-netty

Starter for using Reactor Netty as the embedded reactive HTTP server.

Pom

spring-boot-starter-tomcat

Starter for using Tomcat as the embedded servlet container. Default servlet container

Pom

starter used by spring-boot-starter-web
spring-boot-starter-undertow

Starter for using Undertow as the embedded servlet container. An alternative to

Pom

spring-boot-starter-tomcat

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For a list of additional community contributed starters, see the README file in the spring-boot-starters module on GitHub.

14. Structuring Your Code
Spring Boot does not require any specific code layout to work. However, there are some best practices that help.

14.1 Using the “default” Package
When a class does not include a package declaration, it is considered to be in the “default package”. The use of the “default package” is generally
discouraged and should be avoided. It can cause particular problems for Spring Boot applications that use the @ComponentScan , @EntityScan , or
@SpringBootApplication annotations, since every class from every jar is read.

We recommend that you follow Java’s recommended package naming conventions and use a reversed domain name (for example,
com.example.project ).

14.2 Locating the Main Application Class
We generally recommend that you locate your main application class in a root package above other classes. The @SpringBootApplication
annotation is often placed on your main class, and it implicitly defines a base “search package” for certain items. For example, if you are writing a
JPA application, the package of the @SpringBootApplication annotated class is used to search for @Entity items. Using a root package also
allows component scan to apply only on your project.

If you don’t want to use @SpringBootApplication , the @EnableAutoConfiguration and @ComponentScan annotations that it
imports defines that behaviour so you can also use that instead.

The following listing shows a typical layout:
com
+- example
+- myapplication
+- Application.java
|
+- customer
|
+- Customer.java
|
+- CustomerController.java
|
+- CustomerService.java
|
+- CustomerRepository.java
|
+- order
+- Order.java
+- OrderController.java
+- OrderService.java
+- OrderRepository.java

The Application.java file would declare the main method, along with the basic @SpringBootApplication , as follows:
package com.example.myapplication;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}

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15. Configuration Classes
Spring Boot favors Java-based configuration. Although it is possible to use SpringApplication with XML sources, we generally recommend that
your primary source be a single @Configuration class. Usually the class that defines the main method is a good candidate as the primary
@Configuration .

Many Spring configuration examples have been published on the Internet that use XML configuration. If possible, always try to use the
equivalent Java-based configuration. Searching for Enable* annotations can be a good starting point.

15.1 Importing Additional Configuration Classes
You need not put all your @Configuration into a single class. The @Import annotation can be used to import additional configuration classes.
Alternatively, you can use @ComponentScan to automatically pick up all Spring components, including @Configuration classes.

15.2 Importing XML Configuration
If you absolutely must use XML based configuration, we recommend that you still start with a @Configuration class. You can then use an
@ImportResource annotation to load XML configuration files.

16. Auto-configuration
Spring Boot auto-configuration attempts to automatically configure your Spring application based on the jar dependencies that you have added. For
example, if HSQLDB is on your classpath, and you have not manually configured any database connection beans, then Spring Boot auto-configures
an in-memory database.
You need to opt-in to auto-configuration by adding the @EnableAutoConfiguration or @SpringBootApplication annotations to one of your
@Configuration classes.

You should only ever add one @SpringBootApplication or @EnableAutoConfiguration annotation. We generally recommend
that you add one or the other to your primary @Configuration class only.

16.1 Gradually Replacing Auto-configuration
Auto-configuration is non-invasive. At any point, you can start to define your own configuration to replace specific parts of the auto-configuration. For
example, if you add your own DataSource bean, the default embedded database support backs away.
If you need to find out what auto-configuration is currently being applied, and why, start your application with the --debug switch. Doing so enables
debug logs for a selection of core loggers and logs a conditions report to the console.

16.2 Disabling Specific Auto-configuration Classes
If you find that specific auto-configuration classes that you do not want are being applied, you can use the exclude attribute of
@EnableAutoConfiguration to disable them, as shown in the following example:
import org.springframework.boot.autoconfigure.*;
import org.springframework.boot.autoconfigure.jdbc.*;
import org.springframework.context.annotation.*;
@Configuration
@EnableAutoConfiguration(exclude={DataSourceAutoConfiguration.class})
public class MyConfiguration {
}

If the class is not on the classpath, you can use the excludeName attribute of the annotation and specify the fully qualified name instead. Finally,
you can also control the list of auto-configuration classes to exclude by using the spring.autoconfigure.exclude property.

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You can define exclusions both at the annotation level and by using the property.

17. Spring Beans and Dependency Injection
You are free to use any of the standard Spring Framework techniques to define your beans and their injected dependencies. For simplicity, we often
find that using @ComponentScan (to find your beans) and using @Autowired (to do constructor injection) works well.
If you structure your code as suggested above (locating your application class in a root package), you can add @ComponentScan without any
arguments. All of your application components ( @Component , @Service , @Repository , @Controller etc.) are automatically registered as
Spring Beans.
The following example shows a @Service Bean that uses constructor injection to obtain a required RiskAssessor bean:
package com.example.service;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
@Service
public class DatabaseAccountService implements AccountService {
private final RiskAssessor riskAssessor;
@Autowired
public DatabaseAccountService(RiskAssessor riskAssessor) {
this.riskAssessor = riskAssessor;
}
// ...
}

If a bean has one constructor, you can omit the @Autowired , as shown in the following example:
@Service
public class DatabaseAccountService implements AccountService {
private final RiskAssessor riskAssessor;
public DatabaseAccountService(RiskAssessor riskAssessor) {
this.riskAssessor = riskAssessor;
}
// ...
}

Notice how using constructor injection lets the riskAssessor field be marked as final , indicating that it cannot be subsequently
changed.

18. Using the @SpringBootApplication Annotation
Many Spring Boot developers like their apps to use auto-configuration, component scan and be able to define extra configuration on their
"application class". A single @SpringBootApplication annotation can be used to enable those three features, that is:
@EnableAutoConfiguration : enable Spring Boot’s auto-configuration mechanism
@ComponentScan : enable @Component scan on the package where the application is located (see the best practices)
@Configuration : allow to register extra beans in the context or import additional configuration classes
The @SpringBootApplication annotation is equivalent to using @Configuration , @EnableAutoConfiguration , and @ComponentScan with
their default attributes, as shown in the following example:
package com example myapplication;

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package com.example.myapplication;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication // same as @Configuration @EnableAutoConfiguration @ComponentScan
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}

@SpringBootApplication also provides aliases to customize the attributes of @EnableAutoConfiguration and
@ComponentScan .

None of these features are mandatory and you may choose to replace this single annotation by any of the features that it enables. For
instance, you may not want to use component scan in your application:
package com.example.myapplication;
import
import
import
import

org.springframework.boot.SpringApplication;
org.springframework.context.annotation.ComponentScan
org.springframework.context.annotation.Configuration;
org.springframework.context.annotation.Import;

@Configuration
@EnableAutoConfiguration
@Import({ MyConfig.class, MyAnotherConfig.class })
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}

In this example, Application is just like any other Spring Boot application except that @Component -annotated classes are not
detected automatically and the user-defined beans are imported explicitly (see @Import ).

19. Running Your Application
One of the biggest advantages of packaging your application as a jar and using an embedded HTTP server is that you can run your application as
you would any other. Debugging Spring Boot applications is also easy. You do not need any special IDE plugins or extensions.

This section only covers jar based packaging. If you choose to package your application as a war file, you should refer to your server
and IDE documentation.

19.1 Running from an IDE
You can run a Spring Boot application from your IDE as a simple Java application. However, you first need to import your project. Import steps vary
depending on your IDE and build system. Most IDEs can import Maven projects directly. For example, Eclipse users can select Import… →
Existing Maven Projects from the File menu.
If you cannot directly import your project into your IDE, you may be able to generate IDE metadata by using a build plugin. Maven includes plugins
for Eclipse and IDEA. Gradle offers plugins for various IDEs.

If you accidentally run a web application twice, you see a “Port already in use” error. STS users can use the Relaunch button rather
than the Run button to ensure that any existing instance is closed.
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19.2 Running as a Packaged Application
If you use the Spring Boot Maven or Gradle plugins to create an executable jar, you can run your application using java -jar , as shown in the
following example:
$ java -jar target/myapplication-0.0.1-SNAPSHOT.jar

It is also possible to run a packaged application with remote debugging support enabled. Doing so lets you attach a debugger to your packaged
application, as shown in the following example:
$ java -Xdebug -Xrunjdwp:server=y,transport=dt_socket,address=8000,suspend=n \
-jar target/myapplication-0.0.1-SNAPSHOT.jar

19.3 Using the Maven Plugin
The Spring Boot Maven plugin includes a run goal that can be used to quickly compile and run your application. Applications run in an exploded
form, as they do in your IDE. The following example shows a typical Maven command to run a Spring Boot application:
$ mvn spring-boot:run

You might also want to use the MAVEN_OPTS operating system environment variable, as shown in the following example:
$ export MAVEN_OPTS=-Xmx1024m

19.4 Using the Gradle Plugin
The Spring Boot Gradle plugin also includes a bootRun task that can be used to run your application in an exploded form. The bootRun task is
added whenever you apply the org.springframework.boot and java plugins and is shown in the following example:
$ gradle bootRun

You might also want to use the JAVA_OPTS operating system environment variable, as shown in the following example:
$ export JAVA_OPTS=-Xmx1024m

19.5 Hot Swapping
Since Spring Boot applications are just plain Java applications, JVM hot-swapping should work out of the box. JVM hot swapping is somewhat
limited with the bytecode that it can replace. For a more complete solution, JRebel can be used.
The spring-boot-devtools module also includes support for quick application restarts. See the Chapter 20, Developer Tools section later in this
chapter and the Hot swapping “How-to” for details.

20. Developer Tools
Spring Boot includes an additional set of tools that can make the application development experience a little more pleasant. The
spring-boot-devtools module can be included in any project to provide additional development-time features. To include devtools support, add
the module dependency to your build, as shown in the following listings for Maven and Gradle:
Maven.


org.springframework.boot
spring-boot-devtools
true



Gradle.
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configurations {
developmentOnly
runtimeClasspath {
extendsFrom developmentOnly
}
}
dependencies {
developmentOnly("org.springframework.boot:spring-boot-devtools")
}

Developer tools are automatically disabled when running a fully packaged application. If your application is launched from java -jar
or if it is started from a special classloader, then it is considered a “production application”. Flagging the dependency as optional in
Maven or using a custom`developmentOnly` configuration in Gradle (as shown above) is a best practice that prevents devtools from
being transitively applied to other modules that use your project.

Repackaged archives do not contain devtools by default. If you want to use a certain remote devtools feature, you need to disable the
excludeDevtools build property to include it. The property is supported with both the Maven and Gradle plugins.

20.1 Property Defaults
Several of the libraries supported by Spring Boot use caches to improve performance. For example, template engines cache compiled templates to
avoid repeatedly parsing template files. Also, Spring MVC can add HTTP caching headers to responses when serving static resources.
While caching is very beneficial in production, it can be counter-productive during development, preventing you from seeing the changes you just
made in your application. For this reason, spring-boot-devtools disables the caching options by default.
Cache options are usually configured by settings in your application.properties file. For example, Thymeleaf offers the
spring.thymeleaf.cache property. Rather than needing to set these properties manually, the spring-boot-devtools module automatically
applies sensible development-time configuration.
Because you need more information about web requests while developing Spring MVC and Spring WebFlux applications, developer tools will enable
DEBUG logging for the web logging group. This will give you information about the incoming request, which handler is processing it, the response
outcome, etc. If you wish to log all request details (including potentially sensitive information), you can turn on the
spring.http.log-request-details configuration property.

If you don’t want property defaults to be applied you can set spring.devtools.add-properties to false in your
application.properties .

For a complete list of the properties that are applied by the devtools, see DevToolsPropertyDefaultsPostProcessor.

20.2 Automatic Restart
Applications that use spring-boot-devtools automatically restart whenever files on the classpath change. This can be a useful feature when
working in an IDE, as it gives a very fast feedback loop for code changes. By default, any entry on the classpath that points to a folder is monitored
for changes. Note that certain resources, such as static assets and view templates, do not need to restart the application.
Triggering a restart
As DevTools monitors classpath resources, the only way to trigger a restart is to update the classpath. The way in which you cause the
classpath to be updated depends on the IDE that you are using. In Eclipse, saving a modified file causes the classpath to be updated and
triggers a restart. In IntelliJ IDEA, building the project ( Build -> Build Project ) has the same effect.

As long as forking is enabled, you can also start your application by using the supported build plugins (Maven and Gradle), since
DevTools needs an isolated application classloader to operate properly. By default, Gradle and Maven do that when they detect
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DevTools on the classpath.

Automatic restart works very well when used with LiveReload. See the LiveReload section for details. If you use JRebel, automatic
restarts are disabled in favor of dynamic class reloading. Other devtools features (such as LiveReload and property overrides) can still
be used.

DevTools relies on the application context’s shutdown hook to close it during a restart. It does not work correctly if you have disabled
the shutdown hook ( SpringApplication.setRegisterShutdownHook(false) ).

When deciding if an entry on the classpath should trigger a restart when it changes, DevTools automatically ignores projects named
spring-boot , spring-boot-devtools , spring-boot-autoconfigure , spring-boot-actuator , and spring-boot-starter .

DevTools needs to customize the ResourceLoader used by the ApplicationContext . If your application provides one already, it is
going to be wrapped. Direct override of the getResource method on the ApplicationContext is not supported.

Restart vs Reload
The restart technology provided by Spring Boot works by using two classloaders. Classes that do not change (for example, those from thirdparty jars) are loaded into a base classloader. Classes that you are actively developing are loaded into a restart classloader. When the
application is restarted, the restart classloader is thrown away and a new one is created. This approach means that application restarts are
typically much faster than “cold starts”, since the base classloader is already available and populated.
If you find that restarts are not quick enough for your applications or you encounter classloading issues, you could consider reloading
technologies such as JRebel from ZeroTurnaround. These work by rewriting classes as they are loaded to make them more amenable to
reloading.

20.2.1 Logging changes in condition evaluation
By default, each time your application restarts, a report showing the condition evaluation delta is logged. The report shows the changes to your
application’s auto-configuration as you make changes such as adding or removing beans and setting configuration properties.
To disable the logging of the report, set the following property:
spring.devtools.restart.log-condition-evaluation-delta=false

20.2.2 Excluding Resources
Certain resources do not necessarily need to trigger a restart when they are changed. For example, Thymeleaf templates can be edited in-place. By
default, changing resources in /META-INF/maven , /META-INF/resources , /resources , /static , /public , or /templates does not trigger
a restart but does trigger a live reload. If you want to customize these exclusions, you can use the spring.devtools.restart.exclude property.
For example, to exclude only /static and /public you would set the following property:
spring.devtools.restart.exclude=static/**,public/**

If you want to keep those defaults and add additional exclusions, use the spring.devtools.restart.additional-exclude
property instead.

20.2.3 Watching Additional Paths
You may want your application to be restarted or reloaded when you make changes to files that are not on the classpath. To do so, use the
spring.devtools.restart.additional-paths property to configure additional paths to watch for changes. You can use the
spring.devtools.restart.exclude property described earlier to control whether changes beneath the additional paths trigger a full restart or a
live reload.
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20.2.4 Disabling Restart
If you do not want to use the restart feature, you can disable it by using the spring.devtools.restart.enabled property. In most cases, you can
set this property in your application.properties (doing so still initializes the restart classloader, but it does not watch for file changes).
If you need to completely disable restart support (for example, because it does not work with a specific library), you need to set the
spring.devtools.restart.enabled System property to false before calling SpringApplication.run(…) , as shown in the following
example:
public static void main(String[] args) {
System.setProperty("spring.devtools.restart.enabled", "false");
SpringApplication.run(MyApp.class, args);
}

20.2.5 Using a Trigger File
If you work with an IDE that continuously compiles changed files, you might prefer to trigger restarts only at specific times. To do so, you can use a
“trigger file”, which is a special file that must be modified when you want to actually trigger a restart check. Changing the file only triggers the check
and the restart only occurs if Devtools has detected it has to do something. The trigger file can be updated manually or with an IDE plugin.
To use a trigger file, set the spring.devtools.restart.trigger-file property to the path of your trigger file.

You might want to set spring.devtools.restart.trigger-file as a global setting, so that all your projects behave in the same
way.

20.2.6 Customizing the Restart Classloader
As described earlier in the Restart vs Reload section, restart functionality is implemented by using two classloaders. For most applications, this
approach works well. However, it can sometimes cause classloading issues.
By default, any open project in your IDE is loaded with the “restart” classloader, and any regular .jar file is loaded with the “base” classloader. If
you work on a multi-module project, and not every module is imported into your IDE, you may need to customize things. To do so, you can create a
META-INF/spring-devtools.properties file.
The spring-devtools.properties file can contain properties prefixed with restart.exclude and restart.include . The include elements
are items that should be pulled up into the “restart” classloader, and the exclude elements are items that should be pushed down into the “base”
classloader. The value of the property is a regex pattern that is applied to the classpath, as shown in the following example:
restart.exclude.companycommonlibs=/mycorp-common-[\\w-]+\.jar
restart.include.projectcommon=/mycorp-myproj-[\\w-]+\.jar

All property keys must be unique. As long as a property starts with restart.include. or restart.exclude. it is considered.

All META-INF/spring-devtools.properties from the classpath are loaded. You can package files inside your project, or in the
libraries that the project consumes.

20.2.7 Known Limitations
Restart functionality does not work well with objects that are deserialized by using a standard ObjectInputStream . If you need to deserialize data,
you may need to use Spring’s ConfigurableObjectInputStream in combination with Thread.currentThread().getContextClassLoader() .
Unfortunately, several third-party libraries deserialize without considering the context classloader. If you find such a problem, you need to request a
fix with the original authors.

20.3 LiveReload
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The spring-boot-devtools module includes an embedded LiveReload server that can be used to trigger a browser refresh when a resource is
changed. LiveReload browser extensions are freely available for Chrome, Firefox and Safari from livereload.com.
If you do not want to start the LiveReload server when your application runs, you can set the spring.devtools.livereload.enabled property to
false .

You can only run one LiveReload server at a time. Before starting your application, ensure that no other LiveReload servers are
running. If you start multiple applications from your IDE, only the first has LiveReload support.

20.4 Global Settings
You can configure global devtools settings by adding a file named .spring-boot-devtools.properties to your $HOME folder (note that the
filename starts with “.”). Any properties added to this file apply to all Spring Boot applications on your machine that use devtools. For example, to
configure restart to always use a trigger file, you would add the following property:
~/.spring-boot-devtools.properties.
spring.devtools.reload.trigger-file=.reloadtrigger

Profiles activated in .spring-boot-devtools.properties will not affect the loading of profile-specific configuration files.

20.5 Remote Applications
The Spring Boot developer tools are not limited to local development. You can also use several features when running applications remotely.
Remote support is opt-in. To enable it, you need to make sure that devtools is included in the repackaged archive, as shown in the following
listing:



org.springframework.boot
spring-boot-maven-plugin

false





Then you need to set a spring.devtools.remote.secret property, as shown in the following example:
spring.devtools.remote.secret=mysecret

Enabling spring-boot-devtools on a remote application is a security risk. You should never enable support on a production
deployment.

Remote devtools support is provided in two parts: a server-side endpoint that accepts connections and a client application that you run in your IDE.
The server component is automatically enabled when the spring.devtools.remote.secret property is set. The client component must be
launched manually.

20.5.1 Running the Remote Client Application
The remote client application is designed to be run from within your IDE. You need to run
org.springframework.boot.devtools.RemoteSpringApplication with the same classpath as the remote project that you connect to. The
application’s single required argument is the remote URL to which it connects.

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For example, if you are using Eclipse or STS and you have a project named my-app that you have deployed to Cloud Foundry, you would do the
following:
Select Run Configurations… from the Run menu.
Create a new Java Application “launch configuration”.
Browse for the my-app project.
Use org.springframework.boot.devtools.RemoteSpringApplication as the main class.
Add https://myapp.cfapps.io to the Program arguments (or whatever your remote URL is).
A running remote client might resemble the following listing:
.
____
_
__ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _
___
_
\ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` |
| _ \___ _ __ ___| |_ ___ \ \ \ \
\\/ ___)| |_)| | | | | || (_| []::::::[]
/ -_) ' \/ _ \ _/ -_) ) ) ) )
' |____| .__|_| |_|_| |_\__, |
|_|_\___|_|_|_\___/\__\___|/ / / /
=========|_|==============|___/===================================/_/_/_/
:: Spring Boot Remote :: 2.1.2.BUILD-SNAPSHOT
2015-06-10
2015-06-10
2015-06-10
2015-06-10
2015-06-10

18:25:06.632
18:25:06.671
18:25:07.043
18:25:07.074
18:25:07.130

INFO
INFO
WARN
INFO
INFO

14938
14938
14938
14938
14938

-----------

[
[
[
[
[

main]
main]
main]
main]
main]

o.s.b.devtools.RemoteSpringApplication
s.c.a.AnnotationConfigApplicationContext
o.s.b.d.r.c.RemoteClientConfiguration
o.s.b.d.a.OptionalLiveReloadServer
o.s.b.devtools.RemoteSpringApplication

:
:
:
:
:

Starting RemoteSpringAppl
Refreshing org.springfram
The connection to http://
LiveReload server is runn
Started RemoteSpringAppli

Because the remote client is using the same classpath as the real application it can directly read application properties. This is how
the spring.devtools.remote.secret property is read and passed to the server for authentication.

It is always advisable to use https:// as the connection protocol, so that traffic is encrypted and passwords cannot be intercepted.

If you need to use a proxy to access the remote application, configure the spring.devtools.remote.proxy.host and
spring.devtools.remote.proxy.port properties.

20.5.2 Remote Update
The remote client monitors your application classpath for changes in the same way as the local restart. Any updated resource is pushed to the
remote application and (if required) triggers a restart. This can be helpful if you iterate on a feature that uses a cloud service that you do not have
locally. Generally, remote updates and restarts are much quicker than a full rebuild and deploy cycle.

Files are only monitored when the remote client is running. If you change a file before starting the remote client, it is not pushed to the
remote server.

21. Packaging Your Application for Production
Executable jars can be used for production deployment. As they are self-contained, they are also ideally suited for cloud-based deployment.
For additional “production ready” features, such as health, auditing, and metric REST or JMX end-points, consider adding
spring-boot-actuator . See Part V, “Spring Boot Actuator: Production-ready features” for details.

22. What to Read Next
You should now understand how you can use Spring Boot and some best practices that you should follow. You can now go on to learn about specific
Spring Boot features in depth, or you could skip ahead and read about the “production ready” aspects of Spring Boot.

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Part IV. Spring Boot features
This section dives into the details of Spring Boot. Here you can learn about the key features that you may want to use and customize. If you have
not already done so, you might want to read the "Part II, “Getting Started”" and "Part III, “Using Spring Boot”" sections, so that you have a good
grounding of the basics.

23. SpringApplication
The SpringApplication class provides a convenient way to bootstrap a Spring application that is started from a main() method. In many
situations, you can delegate to the static SpringApplication.run method, as shown in the following example:
public static void main(String[] args) {
SpringApplication.run(MySpringConfiguration.class, args);
}

When your application starts, you should see something similar to the following output:
.
____
_
__ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot ::
v2.1.2.BUILD-SNAPSHOT
2013-07-31
2013-07-31
2014-03-04
2014-03-04

00:08:16.117
00:08:16.166
13:09:54.912
13:09:56.501

INFO
INFO
INFO
INFO

56603
56603
41370
41370

---------

[
[
[
[

main]
main]
main]
main]

o.s.b.s.app.SampleApplication
: Starting SampleApplicatio
ationConfigServletWebServerApplicationContext : Refreshing org.sprin
.t.TomcatServletWebServerFactory : Server initialized with port: 808
o.s.b.s.app.SampleApplication
: Started SampleApplication

By default, INFO logging messages are shown, including some relevant startup details, such as the user that launched the application. If you need
a log level other than INFO , you can set it, as described in Section 26.4, “Log Levels”,

23.1 Startup Failure
If your application fails to start, registered FailureAnalyzers get a chance to provide a dedicated error message and a concrete action to fix the
problem. For instance, if you start a web application on port 8080 and that port is already in use, you should see something similar to the following
message:
***************************
APPLICATION FAILED TO START
***************************
Description:
Embedded servlet container failed to start. Port 8080 was already in use.
Action:
Identify and stop the process that's listening on port 8080 or configure this application to listen on another port.

Spring Boot provides numerous FailureAnalyzer implementations, and you can add your own.

If no failure analyzers are able to handle the exception, you can still display the full conditions report to better understand what went wrong. To do
so, you need to enable the debug property or enable DEBUG logging for
org.springframework.boot.autoconfigure.logging.ConditionEvaluationReportLoggingListener .
For instance, if you are running your application by using java -jar , you can enable the debug property as follows:
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$ java -jar myproject-0.0.1-SNAPSHOT.jar --debug

23.2 Customizing the Banner
The banner that is printed on start up can be changed by adding a banner.txt file to your classpath or by setting the spring.banner.location
property to the location of such a file. If the file has an encoding other than UTF-8, you can set spring.banner.charset . In addition to a text file,
you can also add a banner.gif , banner.jpg , or banner.png image file to your classpath or set the spring.banner.image.location
property. Images are converted into an ASCII art representation and printed above any text banner.
Inside your banner.txt file, you can use any of the following placeholders:

Table 23.1. Banner variables
Variable

Description

${application.version}

The version number of your application, as declared in MANIFEST.MF . For example,
Implementation-Version: 1.0 is printed as 1.0 .

${application.formatted-version}

The version number of your application, as declared in MANIFEST.MF and formatted
for display (surrounded with brackets and prefixed with v ). For example (v1.0) .

${spring-boot.version}

The Spring Boot version that you are using. For example 2.1.2.BUILD-SNAPSHOT .

${spring-boot.formatted-version}

The Spring Boot version that you are using, formatted for display (surrounded with
brackets and prefixed with v ). For example (v2.1.2.BUILD-SNAPSHOT) .

${Ansi.NAME} (or ${AnsiColor.NAME} ,

Where NAME is the name of an ANSI escape code. See AnsiPropertySource for

${AnsiBackground.NAME} ,

details.

${AnsiStyle.NAME} )
${application.title}

The title of your application, as declared in MANIFEST.MF . For example
Implementation-Title: MyApp is printed as MyApp .

The SpringApplication.setBanner(…) method can be used if you want to generate a banner programmatically. Use the
org.springframework.boot.Banner interface and implement your own printBanner() method.

You can also use the spring.main.banner-mode property to determine if the banner has to be printed on System.out ( console ), sent to the
configured logger ( log ), or not produced at all ( off ).
The printed banner is registered as a singleton bean under the following name: springBootBanner .

YAML maps off to false , so be sure to add quotes if you want to disable the banner in your application, as shown in the following
example:
spring:
main:
banner-mode: "off"

23.3 Customizing SpringApplication
If the SpringApplication defaults are not to your taste, you can instead create a local instance and customize it. For example, to turn off the
banner, you could write:
public static void main(String[] args) {
SpringApplication app = new SpringApplication(MySpringConfiguration.class);
app.setBannerMode(Banner.Mode.OFF);
app.run(args);
}

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The constructor arguments passed to SpringApplication are configuration sources for Spring beans. In most cases, these are
references to @Configuration classes, but they could also be references to XML configuration or to packages that should be
scanned.

It is also possible to configure the SpringApplication by using an application.properties file. See Chapter 24, Externalized Configuration
for details.
For a complete list of the configuration options, see the SpringApplication Javadoc.

23.4 Fluent Builder API
If you need to build an ApplicationContext hierarchy (multiple contexts with a parent/child relationship) or if you prefer using a “fluent” builder
API, you can use the SpringApplicationBuilder .
The SpringApplicationBuilder lets you chain together multiple method calls and includes parent and child methods that let you create a
hierarchy, as shown in the following example:
new SpringApplicationBuilder()
.sources(Parent.class)
.child(Application.class)
.bannerMode(Banner.Mode.OFF)
.run(args);

There are some restrictions when creating an ApplicationContext hierarchy. For example, Web components must be contained
within the child context, and the same Environment is used for both parent and child contexts. See the
SpringApplicationBuilder Javadoc for full details.

23.5 Application Events and Listeners
In addition to the usual Spring Framework events, such as ContextRefreshedEvent , a SpringApplication sends some additional application
events.

Some events are actually triggered before the ApplicationContext is created, so you cannot register a listener on those as a
@Bean . You can register them with the SpringApplication.addListeners(…) method or the
SpringApplicationBuilder.listeners(…) method.
If you want those listeners to be registered automatically, regardless of the way the application is created, you can add a
META-INF/spring.factories file to your project and reference your listener(s) by using the
org.springframework.context.ApplicationListener key, as shown in the following example:
org.springframework.context.ApplicationListener=com.example.project.MyListener

Application events are sent in the following order, as your application runs:
1. An ApplicationStartingEvent is sent at the start of a run but before any processing, except for the registration of listeners and initializers.
2. An ApplicationEnvironmentPreparedEvent is sent when the Environment to be used in the context is known but before the context is
created.
3. An ApplicationPreparedEvent is sent just before the refresh is started but after bean definitions have been loaded.
4. An ApplicationStartedEvent is sent after the context has been refreshed but before any application and command-line runners have been
called.
5. An ApplicationReadyEvent is sent after any application and command-line runners have been called. It indicates that the application is ready
to service requests.
6. An ApplicationFailedEvent is sent if there is an exception on startup.

You often need not use application events, but it can be handy to know that they exist. Internally, Spring Boot uses events to handle a
variety of tasks.
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Application events are sent by using Spring Framework’s event publishing mechanism. Part of this mechanism ensures that an event published to
the listeners in a child context is also published to the listeners in any ancestor contexts. As a result of this, if your application uses a hierarchy of
SpringApplication instances, a listener may receive multiple instances of the same type of application event.
To allow your listener to distinguish between an event for its context and an event for a descendant context, it should request that its application
context is injected and then compare the injected context with the context of the event. The context can be injected by implementing
ApplicationContextAware or, if the listener is a bean, by using @Autowired .

23.6 Web Environment
A SpringApplication attempts to create the right type of ApplicationContext on your behalf. The algorithm used to determine a
WebApplicationType is fairly simple:
If Spring MVC is present, an AnnotationConfigServletWebServerApplicationContext is used
If Spring MVC is not present and Spring WebFlux is present, an AnnotationConfigReactiveWebServerApplicationContext is used
Otherwise, AnnotationConfigApplicationContext is used
This means that if you are using Spring MVC and the new WebClient from Spring WebFlux in the same application, Spring MVC will be used by
default. You can override that easily by calling setWebApplicationType(WebApplicationType) .
It is also possible to take complete control of the ApplicationContext type that is used by calling setApplicationContextClass(…) .

It is often desirable to call setWebApplicationType(WebApplicationType.NONE) when using SpringApplication within a JUnit
test.

23.7 Accessing Application Arguments
If you need to access the application arguments that were passed to SpringApplication.run(…) , you can inject a
org.springframework.boot.ApplicationArguments bean. The ApplicationArguments interface provides access to both the raw String[]
arguments as well as parsed option and non-option arguments, as shown in the following example:
import org.springframework.boot.*;
import org.springframework.beans.factory.annotation.*;
import org.springframework.stereotype.*;
@Component
public class MyBean {
@Autowired
public MyBean(ApplicationArguments args) {
boolean debug = args.containsOption("debug");
List files = args.getNonOptionArgs();
// if run with "--debug logfile.txt" debug=true, files=["logfile.txt"]
}
}

Spring Boot also registers a CommandLinePropertySource with the Spring Environment . This lets you also inject single application
arguments by using the @Value annotation.

23.8 Using the ApplicationRunner or CommandLineRunner
If you need to run some specific code once the SpringApplication has started, you can implement the ApplicationRunner or
CommandLineRunner interfaces. Both interfaces work in the same way and offer a single run method, which is called just before
SpringApplication.run(…) completes.
The CommandLineRunner interfaces provides access to application arguments as a simple string array, whereas the ApplicationRunner uses
the ApplicationArguments interface discussed earlier. The following example shows a CommandLineRunner with a run method:

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import org.springframework.boot.*;
import org.springframework.stereotype.*;
@Component
public class MyBean implements CommandLineRunner {
public void run(String... args) {
// Do something...
}
}

If several CommandLineRunner or ApplicationRunner beans are defined that must be called in a specific order, you can additionally implement
the org.springframework.core.Ordered interface or use the org.springframework.core.annotation.Order annotation.

23.9 Application Exit
Each SpringApplication registers a shutdown hook with the JVM to ensure that the ApplicationContext closes gracefully on exit. All the
standard Spring lifecycle callbacks (such as the DisposableBean interface or the @PreDestroy annotation) can be used.
In addition, beans may implement the org.springframework.boot.ExitCodeGenerator interface if they wish to return a specific exit code when
SpringApplication.exit() is called. This exit code can then be passed to System.exit() to return it as a status code, as shown in the
following example:
@SpringBootApplication
public class ExitCodeApplication {
@Bean
public ExitCodeGenerator exitCodeGenerator() {
return () -> 42;
}
public static void main(String[] args) {
System.exit(SpringApplication
.exit(SpringApplication.run(ExitCodeApplication.class, args)));
}
}

Also, the ExitCodeGenerator interface may be implemented by exceptions. When such an exception is encountered, Spring Boot returns the exit
code provided by the implemented getExitCode() method.

23.10 Admin Features
It is possible to enable admin-related features for the application by specifying the spring.application.admin.enabled property. This exposes
the SpringApplicationAdminMXBean on the platform MBeanServer . You could use this feature to administer your Spring Boot application
remotely. This feature could also be useful for any service wrapper implementation.

If you want to know on which HTTP port the application is running, get the property with a key of local.server.port .

Caution
Take care when enabling this feature, as the MBean exposes a method to shutdown the application.

24. Externalized Configuration
Spring Boot lets you externalize your configuration so that you can work with the same application code in different environments. You can use
properties files, YAML files, environment variables, and command-line arguments to externalize configuration. Property values can be injected
directly into your beans by using the @Value annotation, accessed through Spring’s Environment abstraction, or be bound to structured objects
through @ConfigurationProperties .
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Spring Boot uses a very particular PropertySource order that is designed to allow sensible overriding of values. Properties are considered in the
following order:
1. Devtools global settings properties on your home directory ( ~/.spring-boot-devtools.properties when devtools is active).
2. @TestPropertySource annotations on your tests.
3. properties attribute on your tests. Available on @SpringBootTest and the test annotations for testing a particular slice of your application.
4. Command line arguments.
5. Properties from SPRING_APPLICATION_JSON (inline JSON embedded in an environment variable or system property).
6. ServletConfig init parameters.
7. ServletContext init parameters.
8. JNDI attributes from java:comp/env .
9. Java System properties ( System.getProperties() ).
10. OS environment variables.
11. A RandomValuePropertySource that has properties only in random.* .
12. Profile-specific application properties outside of your packaged jar ( application-{profile}.properties and YAML variants).
13. Profile-specific application properties packaged inside your jar ( application-{profile}.properties and YAML variants).
14. Application properties outside of your packaged jar ( application.properties and YAML variants).
15. Application properties packaged inside your jar ( application.properties and YAML variants).
16. @PropertySource annotations on your @Configuration classes.
17. Default properties (specified by setting SpringApplication.setDefaultProperties ).
To provide a concrete example, suppose you develop a @Component that uses a name property, as shown in the following example:
import org.springframework.stereotype.*;
import org.springframework.beans.factory.annotation.*;
@Component
public class MyBean {
@Value("${name}")
private String name;
// ...
}

On your application classpath (for example, inside your jar) you can have an application.properties file that provides a sensible default
property value for name . When running in a new environment, an application.properties file can be provided outside of your jar that overrides
the name . For one-off testing, you can launch with a specific command line switch (for example, java -jar app.jar --name="Spring" ).

The SPRING_APPLICATION_JSON properties can be supplied on the command line with an environment variable. For example, you
could use the following line in a UN*X shell:
$ SPRING_APPLICATION_JSON='{"acme":{"name":"test"}}' java -jar myapp.jar

In the preceding example, you end up with acme.name=test in the Spring Environment . You can also supply the JSON as
spring.application.json in a System property, as shown in the following example:
$ java -Dspring.application.json='{"name":"test"}' -jar myapp.jar

You can also supply the JSON by using a command line argument, as shown in the following example:
$ java -jar myapp.jar --spring.application.json='{"name":"test"}'

You can also supply the JSON as a JNDI variable, as follows: java:comp/env/spring.application.json .

24.1 Configuring Random Values
The RandomValuePropertySource is useful for injecting random values (for example, into secrets or test cases). It can produce integers, longs,
uuids, or strings, as shown in the following example:
my.secret=${random.value}
my.number=${random.int}
my.bignumber=${random.long}
my.uuid=${random.uuid}

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my.number.less.than.ten=${random.int(10)}
my.number.in.range=${random.int[1024,65536]}

The random.int* syntax is OPEN value (,max) CLOSE where the OPEN,CLOSE are any character and value,max are integers. If max is
provided, then value is the minimum value and max is the maximum value (exclusive).

24.2 Accessing Command Line Properties
By default, SpringApplication converts any command line option arguments (that is, arguments starting with -- , such as
--server.port=9000 ) to a property and adds them to the Spring Environment . As mentioned previously, command line properties always
take precedence over other property sources.
If you do not want command line properties to be added to the Environment , you can disable them by using
SpringApplication.setAddCommandLineProperties(false) .

24.3 Application Property Files
SpringApplication loads properties from application.properties files in the following locations and adds them to the Spring Environment :
1. A /config subdirectory of the current directory
2. The current directory
3. A classpath /config package
4. The classpath root
The list is ordered by precedence (properties defined in locations higher in the list override those defined in lower locations).

You can also use YAML ('.yml') files as an alternative to '.properties'.

If you do not like application.properties as the configuration file name, you can switch to another file name by specifying a
spring.config.name environment property. You can also refer to an explicit location by using the spring.config.location environment
property (which is a comma-separated list of directory locations or file paths). The following example shows how to specify a different file name:
$ java -jar myproject.jar --spring.config.name=myproject

The following example shows how to specify two locations:
$ java -jar myproject.jar --spring.config.location=classpath:/default.properties,classpath:/override.properties

spring.config.name and spring.config.location are used very early to determine which files have to be loaded, so they must
be defined as an environment property (typically an OS environment variable, a system property, or a command-line argument).

If spring.config.location contains directories (as opposed to files), they should end in / (and, at runtime, be appended with the names
generated from spring.config.name before being loaded, including profile-specific file names). Files specified in spring.config.location are
used as-is, with no support for profile-specific variants, and are overridden by any profile-specific properties.
Config locations are searched in reverse order. By default, the configured locations are
classpath:/,classpath:/config/,file:./,file:./config/ . The resulting search order is the following:
1. file:./config/
2. file:./
3. classpath:/config/
4. classpath:/
When custom config locations are configured by using spring.config.location , they replace the default locations. For example, if
spring.config.location is configured with the value classpath:/custom-config/,file:./custom-config/ , the search order becomes the
following:
1. file:./custom-config/
2. classpath:custom-config/
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Alternatively, when custom config locations are configured by using spring.config.additional-location , they are used in addition to the
default locations. Additional locations are searched before the default locations. For example, if additional locations of
classpath:/custom-config/,file:./custom-config/ are configured, the search order becomes the following:
1. file:./custom-config/
2. classpath:custom-config/
3. file:./config/
4. file:./
5. classpath:/config/
6. classpath:/
This search ordering lets you specify default values in one configuration file and then selectively override those values in another. You can provide
default values for your application in application.properties (or whatever other basename you choose with spring.config.name ) in one of
the default locations. These default values can then be overridden at runtime with a different file located in one of the custom locations.

If you use environment variables rather than system properties, most operating systems disallow period-separated key names, but you
can use underscores instead (for example, SPRING_CONFIG_NAME instead of spring.config.name ).

If your application runs in a container, then JNDI properties (in java:comp/env ) or servlet context initialization parameters can be
used instead of, or as well as, environment variables or system properties.

24.4 Profile-specific Properties
In addition to application.properties files, profile-specific properties can also be defined by using the following naming convention:
application-{profile}.properties . The Environment has a set of default profiles (by default, [default] ) that are used if no active profiles
are set. In other words, if no profiles are explicitly activated, then properties from application-default.properties are loaded.
Profile-specific properties are loaded from the same locations as standard application.properties , with profile-specific files always overriding
the non-specific ones, whether or not the profile-specific files are inside or outside your packaged jar.
If several profiles are specified, a last-wins strategy applies. For example, profiles specified by the spring.profiles.active property are added
after those configured through the SpringApplication API and therefore take precedence.

If you have specified any files in spring.config.location , profile-specific variants of those files are not considered. Use directories
in spring.config.location if you want to also use profile-specific properties.

24.5 Placeholders in Properties
The values in application.properties are filtered through the existing Environment when they are used, so you can refer back to previously
defined values (for example, from System properties).
app.name=MyApp
app.description=${app.name} is a Spring Boot application

You can also use this technique to create “short” variants of existing Spring Boot properties. See the Section 77.4, “Use ‘Short’
Command Line Arguments” how-to for details.

24.6 Encrypting Properties
Spring Boot does not provide any built in support for encrypting property values, however, it does provide the hook points necessary to modify
values contained in the Spring Environment . The EnvironmentPostProcessor interface allows you to manipulate the Environment before the
application starts. See Section 76.3, “Customize the Environment or ApplicationContext Before It Starts” for details.
If you’re looking for a secure way to store credentials and passwords, the Spring Cloud Vault project provides support for storing externalized
configuration in HashiCorp Vault.
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24.7 Using YAML Instead of Properties
YAML is a superset of JSON and, as such, is a convenient format for specifying hierarchical configuration data. The SpringApplication class
automatically supports YAML as an alternative to properties whenever you have the SnakeYAML library on your classpath.

If you use “Starters”, SnakeYAML is automatically provided by spring-boot-starter .

24.7.1 Loading YAML
Spring Framework provides two convenient classes that can be used to load YAML documents. The YamlPropertiesFactoryBean loads YAML as
Properties and the YamlMapFactoryBean loads YAML as a Map .
For example, consider the following YAML document:
environments:
dev:
url: http://dev.example.com
name: Developer Setup
prod:
url: http://another.example.com
name: My Cool App

The preceding example would be transformed into the following properties:
environments.dev.url=http://dev.example.com
environments.dev.name=Developer Setup
environments.prod.url=http://another.example.com
environments.prod.name=My Cool App

YAML lists are represented as property keys with [index] dereferencers. For example, consider the following YAML:
my:
servers:
- dev.example.com
- another.example.com

The preceding example would be transformed into these properties:
my.servers[0]=dev.example.com
my.servers[1]=another.example.com

To bind to properties like that by using Spring Boot’s Binder utilities (which is what @ConfigurationProperties does), you need to have a
property in the target bean of type java.util.List (or Set ) and you either need to provide a setter or initialize it with a mutable value. For
example, the following example binds to the properties shown previously:
@ConfigurationProperties(prefix="my")
public class Config {
private List servers = new ArrayList();
public List getServers() {
return this.servers;
}
}

24.7.2 Exposing YAML as Properties in the Spring Environment
The YamlPropertySourceLoader class can be used to expose YAML as a PropertySource in the Spring Environment . Doing so lets you use
the @Value annotation with placeholders syntax to access YAML properties.

24.7.3 Multi-profile YAML Documents
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You can specify multiple profile-specific YAML documents in a single file by using a spring.profiles key to indicate when the document applies,
as shown in the following example:
server:
address: 192.168.1.100
--spring:
profiles: development
server:
address: 127.0.0.1
--spring:
profiles: production & eu-central
server:
address: 192.168.1.120

In the preceding example, if the development profile is active, the server.address property is 127.0.0.1 . Similarly, if the production and
eu-central profiles are active, the server.address property is 192.168.1.120 . If the development , production and eu-central profiles
are not enabled, then the value for the property is 192.168.1.100 .

spring.profiles can therefore contain a simple profile name (for example production ) or a profile expression. A profile
expression allows for more complicated profile logic to be expressed, for example production & (eu-central | eu-west) . Check
the reference guide for more details.

If none are explicitly active when the application context starts, the default profiles are activated. So, in the following YAML, we set a value for
spring.security.user.password that is available only in the "default" profile:
server:
port: 8000
--spring:
profiles: default
security:
user:
password: weak

Whereas, in the following example, the password is always set because it is not attached to any profile, and it would have to be explicitly reset in all
other profiles as necessary:
server:
port: 8000
spring:
security:
user:
password: weak

Spring profiles designated by using the spring.profiles element may optionally be negated by using the ! character. If both negated and nonnegated profiles are specified for a single document, at least one non-negated profile must match, and no negated profiles may match.

24.7.4 YAML Shortcomings
YAML files cannot be loaded by using the @PropertySource annotation. So, in the case that you need to load values that way, you need to use a
properties file.

24.8 Type-safe Configuration Properties
Using the @Value("${property}") annotation to inject configuration properties can sometimes be cumbersome, especially if you are working with
multiple properties or your data is hierarchical in nature. Spring Boot provides an alternative method of working with properties that lets strongly
typed beans govern and validate the configuration of your application, as shown in the following example:
package com.example;
import java net InetAddress;

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import
import
import
import

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java.net.InetAddress;
java.util.ArrayList;
java.util.Collections;
java.util.List;

import org.springframework.boot.context.properties.ConfigurationProperties;
@ConfigurationProperties("acme")
public class AcmeProperties {
private boolean enabled;
private InetAddress remoteAddress;
private final Security security = new Security();
public boolean isEnabled() { ... }
public void setEnabled(boolean enabled) { ... }
public InetAddress getRemoteAddress() { ... }
public void setRemoteAddress(InetAddress remoteAddress) { ... }
public Security getSecurity() { ... }
public static class Security {
private String username;
private String password;
private List roles = new ArrayList<>(Collections.singleton("USER"));
public String getUsername() { ... }
public void setUsername(String username) { ... }
public String getPassword() { ... }
public void setPassword(String password) { ... }
public List getRoles() { ... }
public void setRoles(List roles) { ... }
}
}

The preceding POJO defines the following properties:
acme.enabled , with a value of false by default.
acme.remote-address , with a type that can be coerced from String .
acme.security.username , with a nested "security" object whose name is determined by the name of the property. In particular, the return
type is not used at all there and could have been SecurityProperties .
acme.security.password .
acme.security.roles , with a collection of String .

Getters and setters are usually mandatory, since binding is through standard Java Beans property descriptors, just like in Spring MVC.
A setter may be omitted in the following cases:
Maps, as long as they are initialized, need a getter but not necessarily a setter, since they can be mutated by the binder.
Collections and arrays can be accessed either through an index (typically with YAML) or by using a single comma-separated value
(properties). In the latter case, a setter is mandatory. We recommend to always add a setter for such types. If you initialize a
collection, make sure it is not immutable (as in the preceding example).
If nested POJO properties are initialized (like the Security field in the preceding example), a setter is not required. If you want
the binder to create the instance on the fly by using its default constructor, you need a setter.
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Some people use Project Lombok to add getters and setters automatically. Make sure that Lombok does not generate any particular
constructor for such a type, as it is used automatically by the container to instantiate the object.
Finally, only standard Java Bean properties are considered and binding on static properties is not supported.

See also the differences between @Value and @ConfigurationProperties .

You also need to list the properties classes to register in the @EnableConfigurationProperties annotation, as shown in the following example:
@Configuration
@EnableConfigurationProperties(AcmeProperties.class)
public class MyConfiguration {
}

When the @ConfigurationProperties bean is registered that way, the bean has a conventional name: - , where
 is the environment key prefix specified in the @ConfigurationProperties annotation and  is the fully qualified
name of the bean. If the annotation does not provide any prefix, only the fully qualified name of the bean is used.
The bean name in the example above is acme-com.example.AcmeProperties .

Even if the preceding configuration creates a regular bean for AcmeProperties , we recommend that @ConfigurationProperties only deal with
the environment and, in particular, does not inject other beans from the context. Having said that, the @EnableConfigurationProperties
annotation is also automatically applied to your project so that any existing bean annotated with @ConfigurationProperties is configured from
the Environment . You could shortcut MyConfiguration by making sure AcmeProperties is already a bean, as shown in the following example:
@Component
@ConfigurationProperties(prefix="acme")
public class AcmeProperties {
// ... see the preceding example
}

This style of configuration works particularly well with the SpringApplication external YAML configuration, as shown in the following example:
# application.yml
acme:
remote-address: 192.168.1.1
security:
username: admin
roles:
- USER
- ADMIN
# additional configuration as required

To work with @ConfigurationProperties beans, you can inject them in the same way as any other bean, as shown in the following example:
@Service
public class MyService {
private final AcmeProperties properties;
@Autowired
public MyService(AcmeProperties properties) {
this.properties = properties;
}
//...
@PostConstruct
public void openConnection() {
Server server = new Server(this.properties.getRemoteAddress());

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// ...
}

}

Using @ConfigurationProperties also lets you generate metadata files that can be used by IDEs to offer auto-completion for your
own keys. See the Appendix B, Configuration Metadata appendix for details.

24.8.1 Third-party Configuration
As well as using @ConfigurationProperties to annotate a class, you can also use it on public @Bean methods. Doing so can be particularly
useful when you want to bind properties to third-party components that are outside of your control.
To configure a bean from the Environment properties, add @ConfigurationProperties to its bean registration, as shown in the following
example:
@ConfigurationProperties(prefix = "another")
@Bean
public AnotherComponent anotherComponent() {
...
}

Any property defined with the another prefix is mapped onto that AnotherComponent bean in manner similar to the preceding AcmeProperties
example.

24.8.2 Relaxed Binding
Spring Boot uses some relaxed rules for binding Environment properties to @ConfigurationProperties beans, so there does not need to be an
exact match between the Environment property name and the bean property name. Common examples where this is useful include dashseparated environment properties (for example, context-path binds to contextPath ), and capitalized environment properties (for example,
PORT binds to port ).
For example, consider the following @ConfigurationProperties class:
@ConfigurationProperties(prefix="acme.my-project.person")
public class OwnerProperties {
private String firstName;
public String getFirstName() {
return this.firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
}

In the preceding example, the following properties names can all be used:

Table 24.1. relaxed binding
Property

Note

acme.my-project.person.first-name

Kebab case, which is recommended for use in .properties and .yml files.

acme.myProject.person.firstName

Standard camel case syntax.

acme.my_project.person.first_name

Underscore notation, which is an alternative format for use in .properties and .yml files.

ACME_MYPROJECT_PERSON_FIRSTNAME

Upper case format, which is recommended when using system environment variables.

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The prefix value for the annotation must be in kebab case (lowercase and separated by - , such as acme.my-project.person ).

Table 24.2. relaxed binding rules per property source
Property

Simple

List

Source
Camel case, kebab case, or underscore notation

Standard list syntax using [ ] or comma-separated values

YAML Files

Camel case, kebab case, or underscore notation

Standard YAML list syntax or comma-separated values

Environment

Upper case format with underscore as the delimiter. _

Numeric values surrounded by underscores, such as

Variables

should not be used within a property name

MY_ACME_1_OTHER = my.acme[1].other

System

Camel case, kebab case, or underscore notation

Standard list syntax using [ ] or comma-separated values

Properties
Files

properties

We recommend that, when possible, properties are stored in lower-case kebab format, such as my.property-name=acme .

When binding to Map properties, if the key contains anything other than lowercase alpha-numeric characters or - , you need to use the bracket
notation so that the original value is preserved. If the key is not surrounded by [] , any characters that are not alpha-numeric or - are removed.
For example, consider binding the following properties to a Map :
acme:
map:
"[/key1]": value1
"[/key2]": value2
/key3: value3

The properties above will bind to a Map with /key1 , /key2 and key3 as the keys in the map.

24.8.3 Merging Complex Types
When lists are configured in more than one place, overriding works by replacing the entire list.
For example, assume a MyPojo object with name and description attributes that are null by default. The following example exposes a list of
MyPojo objects from AcmeProperties :
@ConfigurationProperties("acme")
public class AcmeProperties {
private final List list = new ArrayList<>();
public List getList() {
return this.list;
}
}

Consider the following configuration:
acme:
list:
- name: my name
description: my description
---

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spring:
profiles: dev
acme:
list:
- name: my another name

If the dev profile is not active, AcmeProperties.list contains one MyPojo entry, as previously defined. If the dev profile is enabled, however,
the list still contains only one entry (with a name of my another name and a description of null ). This configuration does not add a second
MyPojo instance to the list, and it does not merge the items.
When a List is specified in multiple profiles, the one with the highest priority (and only that one) is used. Consider the following example:
acme:
list:
- name: my name
description: my description
- name: another name
description: another description
--spring:
profiles: dev
acme:
list:
- name: my another name

In the preceding example, if the dev profile is active, AcmeProperties.list contains one MyPojo entry (with a name of my another name and
a description of null ). For YAML, both comma-separated lists and YAML lists can be used for completely overriding the contents of the list.
For Map properties, you can bind with property values drawn from multiple sources. However, for the same property in multiple sources, the one
with the highest priority is used. The following example exposes a Map from AcmeProperties :
@ConfigurationProperties("acme")
public class AcmeProperties {
private final Map map = new HashMap<>();
public Map getMap() {
return this.map;
}
}

Consider the following configuration:
acme:
map:
key1:
name: my name 1
description: my description 1
--spring:
profiles: dev
acme:
map:
key1:
name: dev name 1
key2:
name: dev name 2
description: dev description 2

If the dev profile is not active, AcmeProperties.map contains one entry with key key1 (with a name of my name 1 and a description of
my description 1 ). If the dev profile is enabled, however, map contains two entries with keys key1 (with a name of dev name 1 and a
description of my description 1 ) and key2 (with a name of dev name 2 and a description of dev description 2 ).

The preceding merging rules apply to properties from all property sources and not just YAML files.

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24.8.4 Properties Conversion
Spring Boot attempts to coerce the external application properties to the right type when it binds to the @ConfigurationProperties beans. If you
need custom type conversion, you can provide a ConversionService bean (with a bean named conversionService ) or custom property editors
(through a CustomEditorConfigurer bean) or custom Converters (with bean definitions annotated as @ConfigurationPropertiesBinding ).

As this bean is requested very early during the application lifecycle, make sure to limit the dependencies that your
ConversionService is using. Typically, any dependency that you require may not be fully initialized at creation time. You may want
to rename your custom ConversionService if it is not required for configuration keys coercion and only rely on custom converters
qualified with @ConfigurationPropertiesBinding .

Converting durations
Spring Boot has dedicated support for expressing durations. If you expose a java.time.Duration property, the following formats in application
properties are available:
A regular long representation (using milliseconds as the default unit unless a @DurationUnit has been specified)
The standard ISO-8601 format used by java.util.Duration
A more readable format where the value and the unit are coupled (e.g. 10s means 10 seconds)
Consider the following example:
@ConfigurationProperties("app.system")
public class AppSystemProperties {
@DurationUnit(ChronoUnit.SECONDS)
private Duration sessionTimeout = Duration.ofSeconds(30);
private Duration readTimeout = Duration.ofMillis(1000);
public Duration getSessionTimeout() {
return this.sessionTimeout;
}
public void setSessionTimeout(Duration sessionTimeout) {
this.sessionTimeout = sessionTimeout;
}
public Duration getReadTimeout() {
return this.readTimeout;
}
public void setReadTimeout(Duration readTimeout) {
this.readTimeout = readTimeout;
}
}

To specify a session timeout of 30 seconds, 30 , PT30S and 30s are all equivalent. A read timeout of 500ms can be specified in any of the
following form: 500 , PT0.5S and 500ms .
You can also use any of the supported units. These are:
ns for nanoseconds
us for microseconds
ms for milliseconds
s for seconds
m for minutes
h for hours
d for days
The default unit is milliseconds and can be overridden using @DurationUnit as illustrated in the sample above.

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If you are upgrading from a previous version that is simply using Long to express the duration, make sure to define the unit (using
@DurationUnit ) if it isn’t milliseconds alongside the switch to Duration . Doing so gives a transparent upgrade path while
supporting a much richer format.

Converting Data Sizes
Spring Framework has a DataSize value type that allows to express size in bytes. If you expose a DataSize property, the following formats in
application properties are available:
A regular long representation (using bytes as the default unit unless a @DataSizeUnit has been specified)
A more readable format where the value and the unit are coupled (e.g. 10MB means 10 megabytes)
Consider the following example:
@ConfigurationProperties("app.io")
public class AppIoProperties {
@DataSizeUnit(DataUnit.MEGABYTES)
private DataSize bufferSize = DataSize.ofMegabytes(2);
private DataSize sizeThreshold = DataSize.ofBytes(512);
public DataSize getBufferSize() {
return this.bufferSize;
}
public void setBufferSize(DataSize bufferSize) {
this.bufferSize = bufferSize;
}
public DataSize getSizeThreshold() {
return this.sizeThreshold;
}
public void setSizeThreshold(DataSize sizeThreshold) {
this.sizeThreshold = sizeThreshold;
}
}

To specify a buffer size of 10 megabytes, 10 and 10MB are equivalent. A size threshold of 256 bytes can be specified as 256 or 256B .
You can also use any of the supported units. These are:
B for bytes
KB for kilobytes
MB for megabytes
GB for gigabytes
TB for terabytes
The default unit is bytes and can be overridden using @DataSizeUnit as illustrated in the sample above.

If you are upgrading from a previous version that is simply using Long to express the size, make sure to define the unit (using
@DataSizeUnit ) if it isn’t bytes alongside the switch to DataSize . Doing so gives a transparent upgrade path while supporting a
much richer format.

24.8.5 @ConfigurationProperties Validation
Spring Boot attempts to validate @ConfigurationProperties classes whenever they are annotated with Spring’s @Validated annotation. You
can use JSR-303 javax.validation constraint annotations directly on your configuration class. To do so, ensure that a compliant JSR-303
implementation is on your classpath and then add constraint annotations to your fields, as shown in the following example:

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@ConfigurationProperties(prefix="acme")
@Validated
public class AcmeProperties {
@NotNull
private InetAddress remoteAddress;
// ... getters and setters
}

You can also trigger validation by annotating the @Bean method that creates the configuration properties with @Validated .

Although nested properties will also be validated when bound, it’s good practice to also annotate the associated field as @Valid . This ensure that
validation is triggered even if no nested properties are found. The following example builds on the preceding AcmeProperties example:
@ConfigurationProperties(prefix="acme")
@Validated
public class AcmeProperties {
@NotNull
private InetAddress remoteAddress;
@Valid
private final Security security = new Security();
// ... getters and setters
public static class Security {
@NotEmpty
public String username;
// ... getters and setters
}
}

You can also add a custom Spring Validator by creating a bean definition called configurationPropertiesValidator . The @Bean method
should be declared static . The configuration properties validator is created very early in the application’s lifecycle, and declaring the @Bean
method as static lets the bean be created without having to instantiate the @Configuration class. Doing so avoids any problems that may be
caused by early instantiation. There is a property validation sample that shows how to set things up.

The spring-boot-actuator module includes an endpoint that exposes all @ConfigurationProperties beans. Point your web
browser to /actuator/configprops or use the equivalent JMX endpoint. See the "Production ready features" section for details.

24.8.6 @ConfigurationProperties vs. @Value
The @Value annotation is a core container feature, and it does not provide the same features as type-safe configuration properties. The following
table summarizes the features that are supported by @ConfigurationProperties and @Value :
Feature

@ConfigurationProperties

@Value

Relaxed binding

Yes

No

Meta-data support

Yes

No

SpEL evaluation

No

Yes

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If you define a set of configuration keys for your own components, we recommend you group them in a POJO annotated with
@ConfigurationProperties . You should also be aware that, since @Value does not support relaxed binding, it is not a good candidate if you
need to provide the value by using environment variables.
Finally, while you can write a SpEL expression in @Value , such expressions are not processed from application property files.

25. Profiles
Spring Profiles provide a way to segregate parts of your application configuration and make it be available only in certain environments. Any
@Component or @Configuration can be marked with @Profile to limit when it is loaded, as shown in the following example:
@Configuration
@Profile("production")
public class ProductionConfiguration {
// ...
}

You can use a spring.profiles.active Environment property to specify which profiles are active. You can specify the property in any of the
ways described earlier in this chapter. For example, you could include it in your application.properties , as shown in the following example:
spring.profiles.active=dev,hsqldb

You could also specify it on the command line by using the following switch: --spring.profiles.active=dev,hsqldb .

25.1 Adding Active Profiles
The spring.profiles.active property follows the same ordering rules as other properties: The highest PropertySource wins. This means that
you can specify active profiles in application.properties and then replace them by using the command line switch.
Sometimes, it is useful to have profile-specific properties that add to the active profiles rather than replace them. The spring.profiles.include
property can be used to unconditionally add active profiles. The SpringApplication entry point also has a Java API for setting additional profiles
(that is, on top of those activated by the spring.profiles.active property). See the setAdditionalProfiles() method in SpringApplication.
For example, when an application with the following properties is run by using the switch, --spring.profiles.active=prod , the proddb and
prodmq profiles are also activated:
--my.property: fromyamlfile
--spring.profiles: prod
spring.profiles.include:
- proddb
- prodmq

Remember that the spring.profiles property can be defined in a YAML document to determine when this particular document is
included in the configuration. See Section 77.7, “Change Configuration Depending on the Environment” for more details.

25.2 Programmatically Setting Profiles
You can programmatically set active profiles by calling SpringApplication.setAdditionalProfiles(…) before your application runs. It is also
possible to activate profiles by using Spring’s ConfigurableEnvironment interface.

25.3 Profile-specific Configuration Files
Profile-specific variants of both application.properties (or application.yml ) and files referenced through @ConfigurationProperties
are considered as files and loaded. See "Section 24.4, “Profile-specific Properties”" for details.

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26. Logging
Spring Boot uses Commons Logging for all internal logging but leaves the underlying log implementation open. Default configurations are provided
for Java Util Logging, Log4J2, and Logback. In each case, loggers are pre-configured to use console output with optional file output also available.
By default, if you use the “Starters”, Logback is used for logging. Appropriate Logback routing is also included to ensure that dependent libraries that
use Java Util Logging, Commons Logging, Log4J, or SLF4J all work correctly.

There are a lot of logging frameworks available for Java. Do not worry if the above list seems confusing. Generally, you do not need to
change your logging dependencies and the Spring Boot defaults work just fine.

26.1 Log Format
The default log output from Spring Boot resembles the following example:
2014-03-05
2014-03-05
2014-03-05
2014-03-05
2014-03-05

10:57:51.112
10:57:51.253
10:57:51.253
10:57:51.698
10:57:51.702

INFO
INFO
INFO
INFO
INFO

45469
45469
45469
45469
45469

-----------

[
main]
[ost-startStop-1]
[ost-startStop-1]
[ost-startStop-1]
[ost-startStop-1]

org.apache.catalina.core.StandardEngine
o.a.c.c.C.[Tomcat].[localhost].[/]
o.s.web.context.ContextLoader
o.s.b.c.e.ServletRegistrationBean
o.s.b.c.embedded.FilterRegistrationBean

:
:
:
:
:

Starting Servlet Engine:
Initializing Spring embed
Root WebApplicationContex
Mapping servlet: 'dispatc
Mapping filter: 'hiddenHt

The following items are output:
Date and Time: Millisecond precision and easily sortable.
Log Level: ERROR , WARN , INFO , DEBUG , or TRACE .
Process ID.
A --- separator to distinguish the start of actual log messages.
Thread name: Enclosed in square brackets (may be truncated for console output).
Logger name: This is usually the source class name (often abbreviated).
The log message.

Logback does not have a FATAL level. It is mapped to ERROR .

26.2 Console Output
The default log configuration echoes messages to the console as they are written. By default, ERROR -level, WARN -level, and INFO -level messages
are logged. You can also enable a “debug” mode by starting your application with a --debug flag.
$ java -jar myapp.jar --debug

You can also specify debug=true in your application.properties .

When the debug mode is enabled, a selection of core loggers (embedded container, Hibernate, and Spring Boot) are configured to output more
information. Enabling the debug mode does not configure your application to log all messages with DEBUG level.
Alternatively, you can enable a “trace” mode by starting your application with a --trace flag (or trace=true in your application.properties ).
Doing so enables trace logging for a selection of core loggers (embedded container, Hibernate schema generation, and the whole Spring portfolio).

26.2.1 Color-coded Output
If your terminal supports ANSI, color output is used to aid readability. You can set spring.output.ansi.enabled to a supported value to override
the auto detection.
Color coding is configured by using the %clr conversion word. In its simplest form, the converter colors the output according to the log level, as
shown in the following example:

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%clr(%5p)

The following table describes the mapping of log levels to colors:
Level

Color

FATAL

Red

ERROR

Red

WARN

Yellow

INFO

Green

DEBUG

Green

TRACE

Green

Alternatively, you can specify the color or style that should be used by providing it as an option to the conversion. For example, to make the text
yellow, use the following setting:
%clr(%d{yyyy-MM-dd HH:mm:ss.SSS}){yellow}

The following colors and styles are supported:
blue
cyan
faint
green
magenta
red
yellow

26.3 File Output
By default, Spring Boot logs only to the console and does not write log files. If you want to write log files in addition to the console output, you need
to set a logging.file or logging.path property (for example, in your application.properties ).
The following table shows how the logging.* properties can be used together:

Table 26.1. Logging properties
logging.file

logging.path

(none)

(none)

Specific file

(none)

Example

Description
Console only logging.

my.log

Writes to the specified log file. Names can be an exact location or relative to the
current directory.

(none)

Specific directory

/var/log

Writes spring.log to the specified directory. Names can be an exact location or
relative to the current directory.

Log files rotate when they reach 10 MB and, as with console output, ERROR -level, WARN -level, and INFO -level messages are logged by default.
Size limits can be changed using the logging.file.max-size property. Previously rotated files are archived indefinitely unless the
logging.file.max-history property has been set.

The logging system is initialized early in the application lifecycle. Consequently, logging properties are not found in property files
loaded through @PropertySource annotations.
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Logging properties are independent of the actual logging infrastructure. As a result, specific configuration keys (such as
logback.configurationFile for Logback) are not managed by spring Boot.

26.4 Log Levels
All the supported logging systems can have the logger levels set in the Spring Environment (for example, in application.properties ) by using
logging.level.= where level is one of TRACE, DEBUG, INFO, WARN, ERROR, FATAL, or OFF. The root logger
can be configured by using logging.level.root .
The following example shows potential logging settings in application.properties :
logging.level.root=WARN
logging.level.org.springframework.web=DEBUG
logging.level.org.hibernate=ERROR

26.5 Log Groups
It’s often useful to be able to group related loggers together so that they can all be configured at the same time. For example, you might commonly
change the logging levels for all Tomcat related loggers, but you can’t easily remember top level packages.
To help with this, Spring Boot allows you to define logging groups in your Spring Environment . For example, here’s how you could define a
“tomcat” group by adding it to your application.properties :
logging.group.tomcat=org.apache.catalina, org.apache.coyote, org.apache.tomcat

Once defined, you can change the level for all the loggers in the group with a single line:
logging.level.tomcat=TRACE

Spring Boot includes the following pre-defined logging groups that can be used out-of-the-box:
Name

Loggers

web

org.springframework.core.codec , org.springframework.http , org.springframework.web

sql

org.springframework.jdbc.core , org.hibernate.SQL

26.6 Custom Log Configuration
The various logging systems can be activated by including the appropriate libraries on the classpath and can be further customized by providing a
suitable configuration file in the root of the classpath or in a location specified by the following Spring Environment property: logging.config .
You can force Spring Boot to use a particular logging system by using the org.springframework.boot.logging.LoggingSystem system
property. The value should be the fully qualified class name of a LoggingSystem implementation. You can also disable Spring Boot’s logging
configuration entirely by using a value of none .

Since logging is initialized before the ApplicationContext is created, it is not possible to control logging from @PropertySources
in Spring @Configuration files. The only way to change the logging system or disable it entirely is via System properties.

Depending on your logging system, the following files are loaded:
Logging System

Customization

Logback

logback-spring.xml , logback-spring.groovy , logback.xml , or logback.groovy

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Logging System

Customization

Log4j2

log4j2-spring.xml or log4j2.xml

JDK (Java Util Logging)

logging.properties

When possible, we recommend that you use the -spring variants for your logging configuration (for example,
logback-spring.xml rather than logback.xml ). If you use standard configuration locations, Spring cannot completely control log
initialization.

There are known classloading issues with Java Util Logging that cause problems when running from an 'executable jar'. We
recommend that you avoid it when running from an 'executable jar' if at all possible.

To help with the customization, some other properties are transferred from the Spring Environment to System properties, as described in the
following table:
Spring Environment

System Property

Comments

logging.exception-conversion-word

LOG_EXCEPTION_CONVERSION_WORD

The conversion word used when logging exceptions.

logging.file

LOG_FILE

If defined, it is used in the default log configuration.

logging.file.max-size

LOG_FILE_MAX_SIZE

Maximum log file size (if LOG_FILE enabled). (Only
supported with the default Logback setup.)

logging.file.max-history

LOG_FILE_MAX_HISTORY

Maximum number of archive log files to keep (if
LOG_FILE enabled). (Only supported with the default
Logback setup.)

logging.path

LOG_PATH

If defined, it is used in the default log configuration.

logging.pattern.console

CONSOLE_LOG_PATTERN

The log pattern to use on the console (stdout). (Only
supported with the default Logback setup.)

logging.pattern.dateformat

LOG_DATEFORMAT_PATTERN

Appender pattern for log date format. (Only supported
with the default Logback setup.)

logging.pattern.file

FILE_LOG_PATTERN

The log pattern to use in a file (if LOG_FILE is enabled).
(Only supported with the default Logback setup.)

logging.pattern.level

LOG_LEVEL_PATTERN

The format to use when rendering the log level (default
%5p ). (Only supported with the default Logback setup.)

PID

PID

The current process ID (discovered if possible and when
not already defined as an OS environment variable).

All the supported logging systems can consult System properties when parsing their configuration files. See the default configurations in
spring-boot.jar for examples:
Logback
Log4j 2
Java Util logging

If you want to use a placeholder in a logging property, you should use Spring Boot’s syntax and not the syntax of the underlying
framework. Notably, if you use Logback, you should use : as the delimiter between a property name and its default value and not use
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:- .

You can add MDC and other ad-hoc content to log lines by overriding only the LOG_LEVEL_PATTERN (or logging.pattern.level
with Logback). For example, if you use logging.pattern.level=user:%X{user} %5p , then the default log format contains an MDC
entry for "user", if it exists, as shown in the following example.
2015-09-30 12:30:04.031 user:someone INFO 22174 --- [
Handling authenticated request

nio-8080-exec-0] demo.Controller

26.7 Logback Extensions
Spring Boot includes a number of extensions to Logback that can help with advanced configuration. You can use these extensions in your
logback-spring.xml configuration file.

Because the standard logback.xml configuration file is loaded too early, you cannot use extensions in it. You need to either use
logback-spring.xml or define a logging.config property.

The extensions cannot be used with Logback’s configuration scanning. If you attempt to do so, making changes to the configuration
file results in an error similar to one of the following being logged:

ERROR in ch.qos.logback.core.joran.spi.Interpreter@4:71 - no applicable action for [springProperty], current ElementPath is [[
ERROR in ch.qos.logback.core.joran.spi.Interpreter@4:71 - no applicable action for [springProfile], current ElementPath is [[c

26.7.1 Profile-specific Configuration
The  tag lets you optionally include or exclude sections of configuration based on the active Spring profiles. Profile sections are
supported anywhere within the  element. Use the name attribute to specify which profile accepts the configuration. The
 tag can contain a simple profile name (for example staging ) or a profile expression. A profile expression allows for more
complicated profile logic to be expressed, for example production & (eu-central | eu-west) . Check the reference guide for more details. The
following listing shows three sample profiles:










26.7.2 Environment Properties
The  tag lets you expose properties from the Spring Environment for use within Logback. Doing so can be useful if you want
to access values from your application.properties file in your Logback configuration. The tag works in a similar way to Logback’s standard
 tag. However, rather than specifying a direct value , you specify the source of the property (from the Environment ). If you need to
store the property somewhere other than in local scope, you can use the scope attribute. If you need a fallback value (in case the property is not
set in the Environment ), you can use the defaultValue attribute. The following example shows how to expose properties for use within
Logback:


${fluentHost}

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...


The source must be specified in kebab case (such as my.property-name ). However, properties can be added to the
Environment by using the relaxed rules.

27. JSON
Spring Boot provides integration with three JSON mapping libraries:
Gson
Jackson
JSON-B
Jackson is the preferred and default library.

27.1 Jackson
Auto-configuration for Jackson is provided and Jackson is part of spring-boot-starter-json . When Jackson is on the classpath an
ObjectMapper bean is automatically configured. Several configuration properties are provided for customizing the configuration of the
ObjectMapper .

27.2 Gson
Auto-configuration for Gson is provided. When Gson is on the classpath a Gson bean is automatically configured. Several spring.gson.*
configuration properties are provided for customizing the configuration. To take more control, one or more GsonBuilderCustomizer beans can be
used.

27.3 JSON-B
Auto-configuration for JSON-B is provided. When the JSON-B API and an implementation are on the classpath a Jsonb bean will be automatically
configured. The preferred JSON-B implementation is Apache Johnzon for which dependency management is provided.

28. Developing Web Applications
Spring Boot is well suited for web application development. You can create a self-contained HTTP server by using embedded Tomcat, Jetty,
Undertow, or Netty. Most web applications use the spring-boot-starter-web module to get up and running quickly. You can also choose to build
reactive web applications by using the spring-boot-starter-webflux module.
If you have not yet developed a Spring Boot web application, you can follow the "Hello World!" example in the Getting started section.

28.1 The “Spring Web MVC Framework”
The Spring Web MVC framework (often referred to as simply “Spring MVC”) is a rich “model view controller” web framework. Spring MVC lets you
create special @Controller or @RestController beans to handle incoming HTTP requests. Methods in your controller are mapped to HTTP by
using @RequestMapping annotations.
The following code shows a typical @RestController that serves JSON data:
@RestController
@RequestMapping(value="/users")
public class MyRestController {
@RequestMapping(value="/{user}", method=RequestMethod.GET)
public User getUser(@PathVariable Long user) {
// ...
}

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@RequestMapping(value="/{user}/customers", method=RequestMethod.GET)
List getUserCustomers(@PathVariable Long user) {
// ...
}
@RequestMapping(value="/{user}", method=RequestMethod.DELETE)
public User deleteUser(@PathVariable Long user) {
// ...
}

}

Spring MVC is part of the core Spring Framework, and detailed information is available in the reference documentation. There are also several
guides that cover Spring MVC available at spring.io/guides.

28.1.1 Spring MVC Auto-configuration
Spring Boot provides auto-configuration for Spring MVC that works well with most applications.
The auto-configuration adds the following features on top of Spring’s defaults:
Inclusion of ContentNegotiatingViewResolver and BeanNameViewResolver beans.
Support for serving static resources, including support for WebJars (covered later in this document)).
Automatic registration of Converter , GenericConverter , and Formatter beans.
Support for HttpMessageConverters (covered later in this document).
Automatic registration of MessageCodesResolver (covered later in this document).
Static index.html support.
Custom Favicon support (covered later in this document).
Automatic use of a ConfigurableWebBindingInitializer bean (covered later in this document).
If you want to keep Spring Boot MVC features and you want to add additional MVC configuration (interceptors, formatters, view controllers, and
other features), you can add your own @Configuration class of type WebMvcConfigurer but without @EnableWebMvc . If you wish to provide
custom instances of RequestMappingHandlerMapping , RequestMappingHandlerAdapter , or ExceptionHandlerExceptionResolver , you
can declare a WebMvcRegistrationsAdapter instance to provide such components.
If you want to take complete control of Spring MVC, you can add your own @Configuration annotated with @EnableWebMvc .

28.1.2 HttpMessageConverters
Spring MVC uses the HttpMessageConverter interface to convert HTTP requests and responses. Sensible defaults are included out of the box.
For example, objects can be automatically converted to JSON (by using the Jackson library) or XML (by using the Jackson XML extension, if
available, or by using JAXB if the Jackson XML extension is not available). By default, strings are encoded in UTF-8 .
If you need to add or customize converters, you can use Spring Boot’s HttpMessageConverters class, as shown in the following listing:
import org.springframework.boot.autoconfigure.web.HttpMessageConverters;
import org.springframework.context.annotation.*;
import org.springframework.http.converter.*;
@Configuration
public class MyConfiguration {
@Bean
public HttpMessageConverters customConverters() {
HttpMessageConverter additional = ...
HttpMessageConverter another = ...
return new HttpMessageConverters(additional, another);
}
}

Any HttpMessageConverter bean that is present in the context is added to the list of converters. You can also override default converters in the
same way.

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28.1.3 Custom JSON Serializers and Deserializers
If you use Jackson to serialize and deserialize JSON data, you might want to write your own JsonSerializer and JsonDeserializer classes.
Custom serializers are usually registered with Jackson through a module, but Spring Boot provides an alternative @JsonComponent annotation that
makes it easier to directly register Spring Beans.
You can use the @JsonComponent annotation directly on JsonSerializer or JsonDeserializer implementations. You can also use it on
classes that contain serializers/deserializers as inner classes, as shown in the following example:
import
import
import
import

java.io.*;
com.fasterxml.jackson.core.*;
com.fasterxml.jackson.databind.*;
org.springframework.boot.jackson.*;

@JsonComponent
public class Example {
public static class Serializer extends JsonSerializer {
// ...
}
public static class Deserializer extends JsonDeserializer {
// ...
}
}

All @JsonComponent beans in the ApplicationContext are automatically registered with Jackson. Because @JsonComponent is metaannotated with @Component , the usual component-scanning rules apply.
Spring Boot also provides JsonObjectSerializer and JsonObjectDeserializer base classes that provide useful alternatives to the standard
Jackson versions when serializing objects. See JsonObjectSerializer and JsonObjectDeserializer in the Javadoc for details.

28.1.4 MessageCodesResolver
Spring MVC has a strategy for generating error codes for rendering error messages from binding errors: MessageCodesResolver . If you set the
spring.mvc.message-codes-resolver.format property PREFIX_ERROR_CODE or POSTFIX_ERROR_CODE , Spring Boot creates one for you (see
the enumeration in DefaultMessageCodesResolver.Format ).

28.1.5 Static Content
By default, Spring Boot serves static content from a directory called /static (or /public or /resources or /META-INF/resources ) in the
classpath or from the root of the ServletContext . It uses the ResourceHttpRequestHandler from Spring MVC so that you can modify that
behavior by adding your own WebMvcConfigurer and overriding the addResourceHandlers method.
In a stand-alone web application, the default servlet from the container is also enabled and acts as a fallback, serving content from the root of the
ServletContext if Spring decides not to handle it. Most of the time, this does not happen (unless you modify the default MVC configuration),
because Spring can always handle requests through the DispatcherServlet .
By default, resources are mapped on /** , but you can tune that with the spring.mvc.static-path-pattern property. For instance, relocating
all resources to /resources/** can be achieved as follows:
spring.mvc.static-path-pattern=/resources/**

You can also customize the static resource locations by using the spring.resources.static-locations property (replacing the default values
with a list of directory locations). The root Servlet context path, "/" , is automatically added as a location as well.
In addition to the “standard” static resource locations mentioned earlier, a special case is made for Webjars content. Any resources with a path in
/webjars/** are served from jar files if they are packaged in the Webjars format.

Do not use the src/main/webapp directory if your application is packaged as a jar. Although this directory is a common standard, it
works only with war packaging, and it is silently ignored by most build tools if you generate a jar.

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Spring Boot also supports the advanced resource handling features provided by Spring MVC, allowing use cases such as cache-busting static
resources or using version agnostic URLs for Webjars.
To use version agnostic URLs for Webjars, add the webjars-locator-core dependency. Then declare your Webjar. Using jQuery as an example,
adding "/webjars/jquery/jquery.min.js" results in "/webjars/jquery/x.y.z/jquery.min.js" . where x.y.z is the Webjar version.

If you use JBoss, you need to declare the webjars-locator-jboss-vfs dependency instead of the webjars-locator-core .
Otherwise, all Webjars resolve as a 404 .

To use cache busting, the following configuration configures a cache busting solution for all static resources, effectively adding a content hash, such
as  , in URLs:
spring.resources.chain.strategy.content.enabled=true
spring.resources.chain.strategy.content.paths=/**

Links to resources are rewritten in templates at runtime, thanks to a ResourceUrlEncodingFilter that is auto-configured for
Thymeleaf and FreeMarker. You should manually declare this filter when using JSPs. Other template engines are currently not
automatically supported but can be with custom template macros/helpers and the use of the ResourceUrlProvider .

When loading resources dynamically with, for example, a JavaScript module loader, renaming files is not an option. That is why other strategies are
also supported and can be combined. A "fixed" strategy adds a static version string in the URL without changing the file name, as shown in the
following example:
spring.resources.chain.strategy.content.enabled=true
spring.resources.chain.strategy.content.paths=/**
spring.resources.chain.strategy.fixed.enabled=true
spring.resources.chain.strategy.fixed.paths=/js/lib/
spring.resources.chain.strategy.fixed.version=v12

With this configuration, JavaScript modules located under "/js/lib/" use a fixed versioning strategy ( "/v12/js/lib/mymodule.js" ), while
other resources still use the content one (  ).
See ResourceProperties for more supported options.

This feature has been thoroughly described in a dedicated blog post and in Spring Framework’s reference documentation.

28.1.6 Welcome Page
Spring Boot supports both static and templated welcome pages. It first looks for an index.html file in the configured static content locations. If one
is not found, it then looks for an index template. If either is found, it is automatically used as the welcome page of the application.

28.1.7 Custom Favicon
Spring Boot looks for a favicon.ico in the configured static content locations and the root of the classpath (in that order). If such a file is present,
it is automatically used as the favicon of the application.

28.1.8 Path Matching and Content Negotiation
Spring MVC can map incoming HTTP requests to handlers by looking at the request path and matching it to the mappings defined in your
application (for example, @GetMapping annotations on Controller methods).
Spring Boot chooses to disable suffix pattern matching by default, which means that requests like "GET /projects/spring-boot.json" won’t be
matched to @GetMapping("/projects/spring-boot") mappings. This is considered as a best practice for Spring MVC applications. This feature
was mainly useful in the past for HTTP clients which did not send proper "Accept" request headers; we needed to make sure to send the correct
Content Type to the client. Nowadays, Content Negotiation is much more reliable.

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There are other ways to deal with HTTP clients that don’t consistently send proper "Accept" request headers. Instead of using suffix matching, we
can use a query parameter to ensure that requests like "GET /projects/spring-boot?format=json" will be mapped to
@GetMapping("/projects/spring-boot") :
spring.mvc.contentnegotiation.favor-parameter=true
# We can change the parameter name, which is "format" by default:
# spring.mvc.contentnegotiation.parameter-name=myparam
# We can also register additional file extensions/media types with:
spring.mvc.contentnegotiation.media-types.markdown=text/markdown

If you understand the caveats and would still like your application to use suffix pattern matching, the following configuration is required:
spring.mvc.contentnegotiation.favor-path-extension=true
spring.mvc.pathmatch.use-suffix-pattern=true

Alternatively, rather than open all suffix patterns, it’s more secure to just support registered suffix patterns:
spring.mvc.contentnegotiation.favor-path-extension=true
spring.mvc.pathmatch.use-registered-suffix-pattern=true
# You can also register additional file extensions/media types with:
# spring.mvc.contentnegotiation.media-types.adoc=text/asciidoc

28.1.9 ConfigurableWebBindingInitializer
Spring MVC uses a WebBindingInitializer to initialize a WebDataBinder for a particular request. If you create your own
ConfigurableWebBindingInitializer @Bean , Spring Boot automatically configures Spring MVC to use it.

28.1.10 Template Engines
As well as REST web services, you can also use Spring MVC to serve dynamic HTML content. Spring MVC supports a variety of templating
technologies, including Thymeleaf, FreeMarker, and JSPs. Also, many other templating engines include their own Spring MVC integrations.
Spring Boot includes auto-configuration support for the following templating engines:
FreeMarker
Groovy
Thymeleaf
Mustache

If possible, JSPs should be avoided. There are several known limitations when using them with embedded servlet containers.

When you use one of these templating engines with the default configuration, your templates are picked up automatically from
src/main/resources/templates .

Depending on how you run your application, IntelliJ IDEA orders the classpath differently. Running your application in the IDE from its
main method results in a different ordering than when you run your application by using Maven or Gradle or from its packaged jar. This
can cause Spring Boot to fail to find the templates on the classpath. If you have this problem, you can reorder the classpath in the IDE
to place the module’s classes and resources first. Alternatively, you can configure the template prefix to search every templates
directory on the classpath, as follows: classpath*:/templates/ .

28.1.11 Error Handling
By default, Spring Boot provides an /error mapping that handles all errors in a sensible way, and it is registered as a “global” error page in the
servlet container. For machine clients, it produces a JSON response with details of the error, the HTTP status, and the exception message. For
browser clients, there is a “whitelabel” error view that renders the same data in HTML format (to customize it, add a View that resolves to error ).

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To replace the default behavior completely, you can implement ErrorController and register a bean definition of that type or add a bean of type
ErrorAttributes to use the existing mechanism but replace the contents.

The BasicErrorController can be used as a base class for a custom ErrorController . This is particularly useful if you want to
add a handler for a new content type (the default is to handle text/html specifically and provide a fallback for everything else). To
do so, extend BasicErrorController , add a public method with a @RequestMapping that has a produces attribute, and create a
bean of your new type.

You can also define a class annotated with @ControllerAdvice to customize the JSON document to return for a particular controller and/or
exception type, as shown in the following example:
@ControllerAdvice(basePackageClasses = AcmeController.class)
public class AcmeControllerAdvice extends ResponseEntityExceptionHandler {
@ExceptionHandler(YourException.class)
@ResponseBody
ResponseEntity handleControllerException(HttpServletRequest request, Throwable ex) {
HttpStatus status = getStatus(request);
return new ResponseEntity<>(new CustomErrorType(status.value(), ex.getMessage()), status);
}
private HttpStatus getStatus(HttpServletRequest request) {
Integer statusCode = (Integer) request.getAttribute("javax.servlet.error.status_code");
if (statusCode == null) {
return HttpStatus.INTERNAL_SERVER_ERROR;
}
return HttpStatus.valueOf(statusCode);
}
}

In the preceding example, if YourException is thrown by a controller defined in the same package as AcmeController , a JSON representation
of the CustomErrorType POJO is used instead of the ErrorAttributes representation.

Custom Error Pages
If you want to display a custom HTML error page for a given status code, you can add a file to an /error folder. Error pages can either be static
HTML (that is, added under any of the static resource folders) or be built by using templates. The name of the file should be the exact status code or
a series mask.
For example, to map 404 to a static HTML file, your folder structure would be as follows:
src/
+- main/
+- java/
|
+ 
+- resources/
+- public/
+- error/
|
+- 404.html
+- 

To map all 5xx errors by using a FreeMarker template, your folder structure would be as follows:
src/
+- main/
+- java/
|
+ 
+- resources/
+- templates/
+- error/
|
+- 5xx.ftl
+- 

For more complex mappings, you can also add beans that implement the ErrorViewResolver interface, as shown in the following example:
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public class MyErrorViewResolver implements ErrorViewResolver {
@Override
public ModelAndView resolveErrorView(HttpServletRequest request,
HttpStatus status, Map model) {
// Use the request or status to optionally return a ModelAndView
return ...
}
}

You can also use regular Spring MVC features such as @ExceptionHandler methods and @ControllerAdvice . The ErrorController then
picks up any unhandled exceptions.

Mapping Error Pages outside of Spring MVC
For applications that do not use Spring MVC, you can use the ErrorPageRegistrar interface to directly register ErrorPages . This abstraction
works directly with the underlying embedded servlet container and works even if you do not have a Spring MVC DispatcherServlet .
@Bean
public ErrorPageRegistrar errorPageRegistrar(){
return new MyErrorPageRegistrar();
}
// ...
private static class MyErrorPageRegistrar implements ErrorPageRegistrar {
@Override
public void registerErrorPages(ErrorPageRegistry registry) {
registry.addErrorPages(new ErrorPage(HttpStatus.BAD_REQUEST, "/400"));
}
}

If you register an ErrorPage with a path that ends up being handled by a Filter (as is common with some non-Spring web
frameworks, like Jersey and Wicket), then the Filter has to be explicitly registered as an ERROR dispatcher, as shown in the
following example:

@Bean
public FilterRegistrationBean myFilter() {
FilterRegistrationBean registration = new FilterRegistrationBean();
registration.setFilter(new MyFilter());
...
registration.setDispatcherTypes(EnumSet.allOf(DispatcherType.class));
return registration;
}

Note that the default FilterRegistrationBean does not include the ERROR dispatcher type.
CAUTION:When deployed to a servlet container, Spring Boot uses its error page filter to forward a request with an error status to the appropriate
error page. The request can only be forwarded to the correct error page if the response has not already been committed. By default, WebSphere
Application Server 8.0 and later commits the response upon successful completion of a servlet’s service method. You should disable this behavior
by setting com.ibm.ws.webcontainer.invokeFlushAfterService to false .

28.1.12 Spring HATEOAS
If you develop a RESTful API that makes use of hypermedia, Spring Boot provides auto-configuration for Spring HATEOAS that works well with
most applications. The auto-configuration replaces the need to use @EnableHypermediaSupport and registers a number of beans to ease building
hypermedia-based applications, including a LinkDiscoverers (for client side support) and an ObjectMapper configured to correctly marshal
responses into the desired representation. The ObjectMapper is customized by setting the various spring.jackson.* properties or, if one
exists, by a Jackson2ObjectMapperBuilder bean.
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You can take control of Spring HATEOAS’s configuration by using @EnableHypermediaSupport . Note that doing so disables the ObjectMapper
customization described earlier.

28.1.13 CORS Support
Cross-origin resource sharing (CORS) is a W3C specification implemented by most browsers that lets you specify in a flexible way what kind of
cross-domain requests are authorized, instead of using some less secure and less powerful approaches such as IFRAME or JSONP.
As of version 4.2, Spring MVC supports CORS. Using controller method CORS configuration with @CrossOrigin annotations in your Spring Boot
application does not require any specific configuration. Global CORS configuration can be defined by registering a WebMvcConfigurer bean with a
customized addCorsMappings(CorsRegistry) method, as shown in the following example:
@Configuration
public class MyConfiguration {
@Bean
public WebMvcConfigurer corsConfigurer() {
return new WebMvcConfigurer() {
@Override
public void addCorsMappings(CorsRegistry registry) {
registry.addMapping("/api/**");
}
};
}
}

28.2 The “Spring WebFlux Framework”
Spring WebFlux is the new reactive web framework introduced in Spring Framework 5.0. Unlike Spring MVC, it does not require the Servlet API, is
fully asynchronous and non-blocking, and implements the Reactive Streams specification through the Reactor project.
Spring WebFlux comes in two flavors: functional and annotation-based. The annotation-based one is quite close to the Spring MVC model, as
shown in the following example:
@RestController
@RequestMapping("/users")
public class MyRestController {
@GetMapping("/{user}")
public Mono getUser(@PathVariable Long user) {
// ...
}
@GetMapping("/{user}/customers")
public Flux getUserCustomers(@PathVariable Long user) {
// ...
}
@DeleteMapping("/{user}")
public Mono deleteUser(@PathVariable Long user) {
// ...
}
}

“WebFlux.fn”, the functional variant, separates the routing configuration from the actual handling of the requests, as shown in the following example:
@Configuration
public class RoutingConfiguration {
@Bean
public RouterFunction monoRouterFunction(UserHandler userHandler) {
return route(GET("/{user}").and(accept(APPLICATION_JSON)), userHandler::getUser)
.andRoute(GET("/{user}/customers").and(accept(APPLICATION_JSON)), userHandler::getUserCustomer
.andRoute(DELETE("/{user}").and(accept(APPLICATION_JSON)), userHandler::deleteUser);

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}

}
@Component
public class UserHandler {
public Mono getUser(ServerRequest request) {
// ...
}
public Mono getUserCustomers(ServerRequest request) {
// ...
}
public Mono deleteUser(ServerRequest request) {
// ...
}
}

WebFlux is part of the Spring Framework and detailed information is available in its reference documentation.

You can define as many RouterFunction beans as you like to modularize the definition of the router. Beans can be ordered if you
need to apply a precedence.

To get started, add the spring-boot-starter-webflux module to your application.

Adding both spring-boot-starter-web and spring-boot-starter-webflux modules in your application results in Spring Boot
auto-configuring Spring MVC, not WebFlux. This behavior has been chosen because many Spring developers add
spring-boot-starter-webflux to their Spring MVC application to use the reactive WebClient . You can still enforce your choice
by setting the chosen application type to SpringApplication.setWebApplicationType(WebApplicationType.REACTIVE) .

28.2.1 Spring WebFlux Auto-configuration
Spring Boot provides auto-configuration for Spring WebFlux that works well with most applications.
The auto-configuration adds the following features on top of Spring’s defaults:
Configuring codecs for HttpMessageReader and HttpMessageWriter instances (described later in this document).
Support for serving static resources, including support for WebJars (described later in this document).
If you want to keep Spring Boot WebFlux features and you want to add additional WebFlux configuration, you can add your own @Configuration
class of type WebFluxConfigurer but without @EnableWebFlux .
If you want to take complete control of Spring WebFlux, you can add your own @Configuration annotated with @EnableWebFlux .

28.2.2 HTTP Codecs with HttpMessageReaders and HttpMessageWriters
Spring WebFlux uses the HttpMessageReader and HttpMessageWriter interfaces to convert HTTP requests and responses. They are
configured with CodecConfigurer to have sensible defaults by looking at the libraries available in your classpath.
Spring Boot applies further customization by using CodecCustomizer instances. For example, spring.jackson.* configuration keys are applied
to the Jackson codec.
If you need to add or customize codecs, you can create a custom CodecCustomizer component, as shown in the following example:
import org.springframework.boot.web.codec.CodecCustomizer;
@Configuration
public class MyConfiguration {
@Bean

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public CodecCustomizer myCodecCustomizer() {
return codecConfigurer -> {
// ...
}
}

}

You can also leverage Boot’s custom JSON serializers and deserializers.

28.2.3 Static Content
By default, Spring Boot serves static content from a directory called /static (or /public or /resources or /META-INF/resources ) in the
classpath. It uses the ResourceWebHandler from Spring WebFlux so that you can modify that behavior by adding your own WebFluxConfigurer
and overriding the addResourceHandlers method.
By default, resources are mapped on /** , but you can tune that by setting the spring.webflux.static-path-pattern property. For instance,
relocating all resources to /resources/** can be achieved as follows:
spring.webflux.static-path-pattern=/resources/**

You can also customize the static resource locations by using spring.resources.static-locations . Doing so replaces the default values with
a list of directory locations. If you do so, the default welcome page detection switches to your custom locations. So, if there is an index.html in
any of your locations on startup, it is the home page of the application.
In addition to the “standard” static resource locations listed earlier, a special case is made for Webjars content. Any resources with a path in
/webjars/** are served from jar files if they are packaged in the Webjars format.

Spring WebFlux applications do not strictly depend on the Servlet API, so they cannot be deployed as war files and do not use the
src/main/webapp directory.

28.2.4 Template Engines
As well as REST web services, you can also use Spring WebFlux to serve dynamic HTML content. Spring WebFlux supports a variety of templating
technologies, including Thymeleaf, FreeMarker, and Mustache.
Spring Boot includes auto-configuration support for the following templating engines:
FreeMarker
Thymeleaf
Mustache
When you use one of these templating engines with the default configuration, your templates are picked up automatically from
src/main/resources/templates .

28.2.5 Error Handling
Spring Boot provides a WebExceptionHandler that handles all errors in a sensible way. Its position in the processing order is immediately before
the handlers provided by WebFlux, which are considered last. For machine clients, it produces a JSON response with details of the error, the HTTP
status, and the exception message. For browser clients, there is a “whitelabel” error handler that renders the same data in HTML format. You can
also provide your own HTML templates to display errors (see the next section).
The first step to customizing this feature often involves using the existing mechanism but replacing or augmenting the error contents. For that, you
can add a bean of type ErrorAttributes .
To change the error handling behavior, you can implement ErrorWebExceptionHandler and register a bean definition of that type. Because a
WebExceptionHandler is quite low-level, Spring Boot also provides a convenient AbstractErrorWebExceptionHandler to let you handle errors
in a WebFlux functional way, as shown in the following example:
public class CustomErrorWebExceptionHandler extends AbstractErrorWebExceptionHandler {
// Define constructor here

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f

@Override
protected RouterFunction getRoutingFunction(ErrorAttributes errorAttributes) {
return RouterFunctions
.route(aPredicate, aHandler)
.andRoute(anotherPredicate, anotherHandler);
}
}

For a more complete picture, you can also subclass DefaultErrorWebExceptionHandler directly and override specific methods.

Custom Error Pages
If you want to display a custom HTML error page for a given status code, you can add a file to an /error folder. Error pages can either be static
HTML (that is, added under any of the static resource folders) or built with templates. The name of the file should be the exact status code or a
series mask.
For example, to map 404 to a static HTML file, your folder structure would be as follows:
src/
+- main/
+- java/
|
+ 
+- resources/
+- public/
+- error/
|
+- 404.html
+- 

To map all 5xx errors by using a Mustache template, your folder structure would be as follows:
src/
+- main/
+- java/
|
+ 
+- resources/
+- templates/
+- error/
|
+- 5xx.mustache
+- 

28.2.6 Web Filters
Spring WebFlux provides a WebFilter interface that can be implemented to filter HTTP request-response exchanges. WebFilter beans found in
the application context will be automatically used to filter each exchange.
Where the order of the filters is important they can implement Ordered or be annotated with @Order . Spring Boot auto-configuration may
configure web filters for you. When it does so, the orders shown in the following table will be used:
Web Filter

Order

MetricsWebFilter

Ordered.HIGHEST_PRECEDENCE + 1

WebFilterChainProxy (Spring Security)

-100

HttpTraceWebFilter

Ordered.LOWEST_PRECEDENCE - 10

28.3 JAX-RS and Jersey
If you prefer the JAX-RS programming model for REST endpoints, you can use one of the available implementations instead of Spring MVC. Jersey
and Apache CXF work quite well out of the box. CXF requires you to register its Servlet or Filter as a @Bean in your application context.
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Jersey has some native Spring support, so we also provide auto-configuration support for it in Spring Boot, together with a starter.
To get started with Jersey, include the spring-boot-starter-jersey as a dependency and then you need one @Bean of type ResourceConfig
in which you register all the endpoints, as shown in the following example:
@Component
public class JerseyConfig extends ResourceConfig {
public JerseyConfig() {
register(Endpoint.class);
}
}

Jersey’s support for scanning executable archives is rather limited. For example, it cannot scan for endpoints in a package found in a
fully executable jar file or in WEB-INF/classes when running an executable war file. To avoid this limitation, the packages method
should not be used, and endpoints should be registered individually by using the register method, as shown in the preceding
example.

For more advanced customizations, you can also register an arbitrary number of beans that implement ResourceConfigCustomizer .
All the registered endpoints should be @Components with HTTP resource annotations ( @GET and others), as shown in the following example:
@Component
@Path("/hello")
public class Endpoint {
@GET
public String message() {
return "Hello";
}
}

Since the Endpoint is a Spring @Component , its lifecycle is managed by Spring and you can use the @Autowired annotation to inject
dependencies and use the @Value annotation to inject external configuration. By default, the Jersey servlet is registered and mapped to /* . You
can change the mapping by adding @ApplicationPath to your ResourceConfig .
By default, Jersey is set up as a Servlet in a @Bean of type ServletRegistrationBean named jerseyServletRegistration . By default, the
servlet is initialized lazily, but you can customize that behavior by setting spring.jersey.servlet.load-on-startup . You can disable or
override that bean by creating one of your own with the same name. You can also use a filter instead of a servlet by setting
spring.jersey.type=filter (in which case, the @Bean to replace or override is jerseyFilterRegistration ). The filter has an @Order ,
which you can set with spring.jersey.filter.order . Both the servlet and the filter registrations can be given init parameters by using
spring.jersey.init.* to specify a map of properties.
There is a Jersey sample so that you can see how to set things up.

28.4 Embedded Servlet Container Support
Spring Boot includes support for embedded Tomcat, Jetty, and Undertow servers. Most developers use the appropriate “Starter” to obtain a fully
configured instance. By default, the embedded server listens for HTTP requests on port 8080 .

If you choose to use Tomcat on CentOS, be aware that, by default, a temporary directory is used to store compiled JSPs, file uploads,
and so on. This directory may be deleted by tmpwatch while your application is running, leading to failures. To avoid this behavior,
you may want to customize your tmpwatch configuration such that tomcat.* directories are not deleted or configure
server.tomcat.basedir such that embedded Tomcat uses a different location.

28.4.1 Servlets, Filters, and listeners

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When using an embedded servlet container, you can register servlets, filters, and all the listeners (such as HttpSessionListener ) from the
Servlet spec, either by using Spring beans or by scanning for Servlet components.

Registering Servlets, Filters, and Listeners as Spring Beans
Any Servlet , Filter , or servlet *Listener instance that is a Spring bean is registered with the embedded container. This can be particularly
convenient if you want to refer to a value from your application.properties during configuration.
By default, if the context contains only a single Servlet, it is mapped to / . In the case of multiple servlet beans, the bean name is used as a path
prefix. Filters map to /* .
If convention-based mapping is not flexible enough, you can use the ServletRegistrationBean , FilterRegistrationBean , and
ServletListenerRegistrationBean classes for complete control.
Spring Boot ships with many auto-configurations that may define Filter beans. Here are a few examples of Filters and their respective order (lower
order value means higher precedence):
Servlet Filter

Order

OrderedCharacterEncodingFilter

Ordered.HIGHEST_PRECEDENCE

WebMvcMetricsFilter

Ordered.HIGHEST_PRECEDENCE + 1

ErrorPageFilter

Ordered.HIGHEST_PRECEDENCE + 1

HttpTraceFilter

Ordered.LOWEST_PRECEDENCE - 10

It is usually safe to leave Filter beans unordered.
If a specific order is required, you should avoid configuring a Filter that reads the request body at Ordered.HIGHEST_PRECEDENCE , since it might go
against the character encoding configuration of your application. If a Servlet filter wraps the request, it should be configured with an order that is less
than or equal to OrderedFilter.REQUEST_WRAPPER_FILTER_MAX_ORDER .

28.4.2 Servlet Context Initialization
Embedded servlet containers do not directly execute the Servlet 3.0+ javax.servlet.ServletContainerInitializer interface or Spring’s
org.springframework.web.WebApplicationInitializer interface. This is an intentional design decision intended to reduce the risk that third
party libraries designed to run inside a war may break Spring Boot applications.
If you need to perform servlet context initialization in a Spring Boot application, you should register a bean that implements the
org.springframework.boot.web.servlet.ServletContextInitializer interface. The single onStartup method provides access to the
ServletContext and, if necessary, can easily be used as an adapter to an existing WebApplicationInitializer .

Scanning for Servlets, Filters, and listeners
When using an embedded container, automatic registration of classes annotated with @WebServlet , @WebFilter , and @WebListener can be
enabled by using @ServletComponentScan .

@ServletComponentScan has no effect in a standalone container, where the container’s built-in discovery mechanisms are used
instead.

28.4.3 The ServletWebServerApplicationContext
Under the hood, Spring Boot uses a different type of ApplicationContext for embedded servlet container support. The
ServletWebServerApplicationContext is a special type of WebApplicationContext that bootstraps itself by searching for a single
ServletWebServerFactory bean. Usually a TomcatServletWebServerFactory , JettyServletWebServerFactory , or
UndertowServletWebServerFactory has been auto-configured.

You usually do not need to be aware of these implementation classes. Most applications are auto-configured, and the appropriate
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ApplicationContext and ServletWebServerFactory are created on your behalf.

28.4.4 Customizing Embedded Servlet Containers
Common servlet container settings can be configured by using Spring Environment properties. Usually, you would define the properties in your
application.properties file.
Common server settings include:
Network settings: Listen port for incoming HTTP requests ( server.port ), interface address to bind to server.address , and so on.
Session settings: Whether the session is persistent ( server.servlet.session.persistence ), session timeout
( server.servlet.session.timeout ), location of session data ( server.servlet.session.store-dir ), and session-cookie configuration
( server.servlet.session.cookie.* ).
Error management: Location of the error page ( server.error.path ) and so on.
SSL
HTTP compression
Spring Boot tries as much as possible to expose common settings, but this is not always possible. For those cases, dedicated namespaces offer
server-specific customizations (see server.tomcat and server.undertow ). For instance, access logs can be configured with specific features of
the embedded servlet container.

See the ServerProperties class for a complete list.

Programmatic Customization
If you need to programmatically configure your embedded servlet container, you can register a Spring bean that implements the
WebServerFactoryCustomizer interface. WebServerFactoryCustomizer provides access to the ConfigurableServletWebServerFactory ,
which includes numerous customization setter methods. The following example shows programmatically setting the port:
import org.springframework.boot.web.server.WebServerFactoryCustomizer;
import org.springframework.boot.web.servlet.server.ConfigurableServletWebServerFactory;
import org.springframework.stereotype.Component;
@Component
public class CustomizationBean implements WebServerFactoryCustomizer {
@Override
public void customize(ConfigurableServletWebServerFactory server) {
server.setPort(9000);
}
}

TomcatServletWebServerFactory , JettyServletWebServerFactory and UndertowServletWebServerFactory are dedicated
variants of ConfigurableServletWebServerFactory that have additional customization setter methods for Tomcat, Jetty and
Undertow respectively.

Customizing ConfigurableServletWebServerFactory Directly
If the preceding customization techniques are too limited, you can register the TomcatServletWebServerFactory ,
JettyServletWebServerFactory , or UndertowServletWebServerFactory bean yourself.
@Bean
public ConfigurableServletWebServerFactory webServerFactory() {
TomcatServletWebServerFactory factory = new TomcatServletWebServerFactory();
factory.setPort(9000);
factory.setSessionTimeout(10, TimeUnit.MINUTES);
factory.addErrorPages(new ErrorPage(HttpStatus.NOT_FOUND, "/notfound.html"));
return factory;
}

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Setters are provided for many configuration options. Several protected method “hooks” are also provided should you need to do something more
exotic. See the source code documentation for details.

28.4.5 JSP Limitations
When running a Spring Boot application that uses an embedded servlet container (and is packaged as an executable archive), there are some
limitations in the JSP support.
With Jetty and Tomcat, it should work if you use war packaging. An executable war will work when launched with java -jar , and will also be
deployable to any standard container. JSPs are not supported when using an executable jar.
Undertow does not support JSPs.
Creating a custom error.jsp page does not override the default view for error handling. Custom error pages should be used instead.
There is a JSP sample so that you can see how to set things up.

28.5 Embedded Reactive Server Support
Spring Boot includes support for the following embedded reactive web servers: Reactor Netty, Tomcat, Jetty, and Undertow. Most developers use
the appropriate “Starter” to obtain a fully configured instance. By default, the embedded server listens for HTTP requests on port 8080.

28.6 Reactive Server Resources Configuration
When auto-configuring a Reactor Netty or Jetty server, Spring Boot will create specific beans that will provide HTTP resources to the server
instance: ReactorResourceFactory or JettyResourceFactory .
By default, those resources will be also shared with the Reactor Netty and Jetty clients for optimal performances, given:
the same technology is used for server and client
the client instance is built using the WebClient.Builder bean auto-configured by Spring Boot
Developers can override the resource configuration for Jetty and Reactor Netty by providing a custom ReactorResourceFactory or
JettyResourceFactory bean - this will be applied to both clients and servers.
You can learn more about the resource configuration on the client side in the WebClient Runtime section.

29. Security
If Spring Security is on the classpath, then web applications are secured by default. Spring Boot relies on Spring Security’s content-negotiation
strategy to determine whether to use httpBasic or formLogin . To add method-level security to a web application, you can also add
@EnableGlobalMethodSecurity with your desired settings. Additional information can be found in the Spring Security Reference Guide.
The default UserDetailsService has a single user. The user name is user , and the password is random and is printed at INFO level when the
application starts, as shown in the following example:
Using generated security password: 78fa095d-3f4c-48b1-ad50-e24c31d5cf35

If you fine-tune your logging configuration, ensure that the org.springframework.boot.autoconfigure.security category is set
to log INFO -level messages. Otherwise, the default password is not printed.

You can change the username and password by providing a spring.security.user.name and spring.security.user.password .
The basic features you get by default in a web application are:
A UserDetailsService (or ReactiveUserDetailsService in case of a WebFlux application) bean with in-memory store and a single user
with a generated password (see SecurityProperties.User for the properties of the user).
Form-based login or HTTP Basic security (depending on Content-Type) for the entire application (including actuator endpoints if actuator is on
the classpath).
A DefaultAuthenticationEventPublisher for publishing authentication events.
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You can provide a different AuthenticationEventPublisher by adding a bean for it.

29.1 MVC Security
The default security configuration is implemented in SecurityAutoConfiguration and UserDetailsServiceAutoConfiguration .
SecurityAutoConfiguration imports SpringBootWebSecurityConfiguration for web security and
UserDetailsServiceAutoConfiguration configures authentication, which is also relevant in non-web applications. To switch off the default web
application security configuration completely, you can add a bean of type WebSecurityConfigurerAdapter (doing so does not disable the
UserDetailsService configuration or Actuator’s security).
To also switch off the UserDetailsService configuration, you can add a bean of type UserDetailsService , AuthenticationProvider , or
AuthenticationManager . There are several secure applications in the Spring Boot samples to get you started with common use cases.
Access rules can be overridden by adding a custom WebSecurityConfigurerAdapter . Spring Boot provides convenience methods that can be
used to override access rules for actuator endpoints and static resources. EndpointRequest can be used to create a RequestMatcher that is
based on the management.endpoints.web.base-path property. PathRequest can be used to create a RequestMatcher for resources in
commonly used locations.

29.2 WebFlux Security
Similar to Spring MVC applications, you can secure your WebFlux applications by adding the spring-boot-starter-security dependency. The
default security configuration is implemented in ReactiveSecurityAutoConfiguration and UserDetailsServiceAutoConfiguration .
ReactiveSecurityAutoConfiguration imports WebFluxSecurityConfiguration for web security and
UserDetailsServiceAutoConfiguration configures authentication, which is also relevant in non-web applications. To switch off the default web
application security configuration completely, you can add a bean of type WebFilterChainProxy (doing so does not disable the
UserDetailsService configuration or Actuator’s security).
To also switch off the UserDetailsService configuration, you can add a bean of type ReactiveUserDetailsService or
ReactiveAuthenticationManager .
Access rules can be configured by adding a custom SecurityWebFilterChain . Spring Boot provides convenience methods that can be used to
override access rules for actuator endpoints and static resources. EndpointRequest can be used to create a ServerWebExchangeMatcher that is
based on the management.endpoints.web.base-path property.
PathRequest can be used to create a ServerWebExchangeMatcher for resources in commonly used locations.
For example, you can customize your security configuration by adding something like:
@Bean
public SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http) {
return http
.authorizeExchange()
.matchers(PathRequest.toStaticResources().atCommonLocations()).permitAll()
.pathMatchers("/foo", "/bar")
.authenticated().and()
.formLogin().and()
.build();
}

29.3 OAuth2
OAuth2 is a widely used authorization framework that is supported by Spring.

29.3.1 Client
If you have spring-security-oauth2-client on your classpath, you can take advantage of some auto-configuration to make it easy to set up an
OAuth2/Open ID Connect clients. This configuration makes use of the properties under OAuth2ClientProperties . The same properties are
applicable to both servlet and reactive applications.
You can register multiple OAuth2 clients and providers under the spring.security.oauth2.client prefix, as shown in the following example:
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spring.security.oauth2.client.registration.my-client-1.client-id=abcd
spring.security.oauth2.client.registration.my-client-1.client-secret=password
spring.security.oauth2.client.registration.my-client-1.client-name=Client for user scope
spring.security.oauth2.client.registration.my-client-1.provider=my-oauth-provider
spring.security.oauth2.client.registration.my-client-1.scope=user
spring.security.oauth2.client.registration.my-client-1.redirect-uri-template=http://my-redirect-uri.com
spring.security.oauth2.client.registration.my-client-1.client-authentication-method=basic
spring.security.oauth2.client.registration.my-client-1.authorization-grant-type=authorization_code
spring.security.oauth2.client.registration.my-client-2.client-id=abcd
spring.security.oauth2.client.registration.my-client-2.client-secret=password
spring.security.oauth2.client.registration.my-client-2.client-name=Client for email scope
spring.security.oauth2.client.registration.my-client-2.provider=my-oauth-provider
spring.security.oauth2.client.registration.my-client-2.scope=email
spring.security.oauth2.client.registration.my-client-2.redirect-uri-template=http://my-redirect-uri.com
spring.security.oauth2.client.registration.my-client-2.client-authentication-method=basic
spring.security.oauth2.client.registration.my-client-2.authorization-grant-type=authorization_code
spring.security.oauth2.client.provider.my-oauth-provider.authorization-uri=http://my-auth-server/oauth/authorize
spring.security.oauth2.client.provider.my-oauth-provider.token-uri=http://my-auth-server/oauth/token
spring.security.oauth2.client.provider.my-oauth-provider.user-info-uri=http://my-auth-server/userinfo
spring.security.oauth2.client.provider.my-oauth-provider.user-info-authentication-method=header
spring.security.oauth2.client.provider.my-oauth-provider.jwk-set-uri=http://my-auth-server/token_keys
spring.security.oauth2.client.provider.my-oauth-provider.user-name-attribute=name

For OpenID Connect providers that support OpenID Connect discovery, the configuration can be further simplified. The provider needs to be
configured with an issuer-uri which is the URI that the it asserts as its Issuer Identifier. For example, if the issuer-uri provided is
"https://example.com", then an OpenID Provider Configuration Request will be made to "https://example.com/.well-known/openidconfiguration". The result is expected to be an OpenID Provider Configuration Response . The following example shows how an OpenID
Connect Provider can be configured with the issuer-uri :
spring.security.oauth2.client.provider.oidc-provider.issuer-uri=https://dev-123456.oktapreview.com/oauth2/default/

By default, Spring Security’s OAuth2LoginAuthenticationFilter only processes URLs matching /login/oauth2/code/* . If you want to
customize the redirect-uri to use a different pattern, you need to provide configuration to process that custom pattern. For example, for servlet
applications, you can add your own WebSecurityConfigurerAdapter that resembles the following:
public class OAuth2LoginSecurityConfig extends WebSecurityConfigurerAdapter {
@Override
protected void configure(HttpSecurity http) throws Exception {
http
.authorizeRequests()
.anyRequest().authenticated()
.and()
.oauth2Login()
.redirectionEndpoint()
.baseUri("/custom-callback");
}
}

OAuth2 client registration for common providers
For common OAuth2 and OpenID providers, including Google, Github, Facebook, and Okta, we provide a set of provider defaults ( google ,
github , facebook , and okta , respectively).
If you do not need to customize these providers, you can set the provider attribute to the one for which you need to infer defaults. Also, if the key
for the client registration matches a default supported provider, Spring Boot infers that as well.
In other words, the two configurations in the following example use the Google provider:
spring.security.oauth2.client.registration.my-client.client-id=abcd
spring.security.oauth2.client.registration.my-client.client-secret=password
spring.security.oauth2.client.registration.my-client.provider=google
spring.security.oauth2.client.registration.google.client-id=abcd
spring.security.oauth2.client.registration.google.client-secret=password

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29.3.2 Resource Server
If you have spring-security-oauth2-resource-server on your classpath, Spring Boot can set up an OAuth2 Resource Server as long as a
JWK Set URI or OIDC Issuer URI is specified, as shown in the following examples:
spring.security.oauth2.resourceserver.jwt.jwk-set-uri=https://example.com/oauth2/default/v1/keys
spring.security.oauth2.resourceserver.jwt.issuer-uri=https://dev-123456.oktapreview.com/oauth2/default/

The same properties are applicable for both servlet and reactive applications.
Alternatively, you can define your own JwtDecoder bean for servlet applications or a ReactiveJwtDecoder for reactive applications.

29.3.3 Authorization Server
Currently, Spring Security does not provide support for implementing an OAuth 2.0 Authorization Server. However, this functionality is available from
the Spring Security OAuth project, which will eventually be superseded by Spring Security completely. Until then, you can use the
spring-security-oauth2-autoconfigure module to easily set up an OAuth 2.0 authorization server; see its documentation for instructions.

29.4 Actuator Security
For security purposes, all actuators other than /health and /info are disabled by default. The
management.endpoints.web.exposure.include property can be used to enable the actuators.
If Spring Security is on the classpath and no other WebSecurityConfigurerAdapter is present, all actuators other than /health and /info are
secured by Spring Boot auto-configuration. If you define a custom WebSecurityConfigurerAdapter , Spring Boot auto-configuration will back off
and you will be in full control of actuator access rules.

Before setting the management.endpoints.web.exposure.include , ensure that the exposed actuators do not contain sensitive
information and/or are secured by placing them behind a firewall or by something like Spring Security.

29.4.1 Cross Site Request Forgery Protection
Since Spring Boot relies on Spring Security’s defaults, CSRF protection is turned on by default. This means that the actuator endpoints that require
a POST (shutdown and loggers endpoints), PUT or DELETE will get a 403 forbidden error when the default security configuration is in use.

We recommend disabling CSRF protection completely only if you are creating a service that is used by non-browser clients.

Additional information about CSRF protection can be found in the Spring Security Reference Guide.

30. Working with SQL Databases
The Spring Framework provides extensive support for working with SQL databases, from direct JDBC access using JdbcTemplate to complete
“object relational mapping” technologies such as Hibernate. Spring Data provides an additional level of functionality: creating Repository
implementations directly from interfaces and using conventions to generate queries from your method names.

30.1 Configure a DataSource
Java’s javax.sql.DataSource interface provides a standard method of working with database connections. Traditionally, a 'DataSource' uses a
URL along with some credentials to establish a database connection.

See the “How-to” section for more advanced examples, typically to take full control over the configuration of the DataSource.

30.1.1 Embedded Database Support
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It is often convenient to develop applications by using an in-memory embedded database. Obviously, in-memory databases do not provide
persistent storage. You need to populate your database when your application starts and be prepared to throw away data when your application
ends.

The “How-to” section includes a section on how to initialize a database.

Spring Boot can auto-configure embedded H2, HSQL, and Derby databases. You need not provide any connection URLs. You need only include a
build dependency to the embedded database that you want to use.

If you are using this feature in your tests, you may notice that the same database is reused by your whole test suite regardless of the
number of application contexts that you use. If you want to make sure that each context has a separate embedded database, you
should set spring.datasource.generate-unique-name to true .

For example, the typical POM dependencies would be as follows:

org.springframework.boot
spring-boot-starter-data-jpa


org.hsqldb
hsqldb
runtime


You need a dependency on spring-jdbc for an embedded database to be auto-configured. In this example, it is pulled in transitively
through spring-boot-starter-data-jpa .

If, for whatever reason, you do configure the connection URL for an embedded database, take care to ensure that the database’s
automatic shutdown is disabled. If you use H2, you should use DB_CLOSE_ON_EXIT=FALSE to do so. If you use HSQLDB, you should
ensure that shutdown=true is not used. Disabling the database’s automatic shutdown lets Spring Boot control when the database is
closed, thereby ensuring that it happens once access to the database is no longer needed.

30.1.2 Connection to a Production Database
Production database connections can also be auto-configured by using a pooling DataSource . Spring Boot uses the following algorithm for
choosing a specific implementation:
1. We prefer HikariCP for its performance and concurrency. If HikariCP is available, we always choose it.
2. Otherwise, if the Tomcat pooling DataSource is available, we use it.
3. If neither HikariCP nor the Tomcat pooling datasource are available and if Commons DBCP2 is available, we use it.
If you use the spring-boot-starter-jdbc or spring-boot-starter-data-jpa “starters”, you automatically get a dependency to HikariCP .

You can bypass that algorithm completely and specify the connection pool to use by setting the spring.datasource.type property.
This is especially important if you run your application in a Tomcat container, as tomcat-jdbc is provided by default.

Additional connection pools can always be configured manually. If you define your own DataSource bean, auto-configuration does
not occur.

DataSource configuration is controlled by external configuration properties in spring.datasource.* . For example, you might declare the following
section in application.properties :

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spring.datasource.url=jdbc:mysql://localhost/test
spring.datasource.username=dbuser
spring.datasource.password=dbpass
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

You should at least specify the URL by setting the spring.datasource.url property. Otherwise, Spring Boot tries to auto-configure
an embedded database.

You often do not need to specify the driver-class-name , since Spring Boot can deduce it for most databases from the url .

For a pooling DataSource to be created, we need to be able to verify that a valid Driver class is available, so we check for that
before doing anything. In other words, if you set spring.datasource.driver-class-name=com.mysql.jdbc.Driver , then that
class has to be loadable.

See DataSourceProperties for more of the supported options. These are the standard options that work regardless of the actual implementation.
It is also possible to fine-tune implementation-specific settings by using their respective prefix ( spring.datasource.hikari.* ,
spring.datasource.tomcat.* , and spring.datasource.dbcp2.* ). Refer to the documentation of the connection pool implementation you are
using for more details.
For instance, if you use the Tomcat connection pool, you could customize many additional settings, as shown in the following example:
# Number of ms to wait before throwing an exception if no connection is available.
spring.datasource.tomcat.max-wait=10000
# Maximum number of active connections that can be allocated from this pool at the same time.
spring.datasource.tomcat.max-active=50
# Validate the connection before borrowing it from the pool.
spring.datasource.tomcat.test-on-borrow=true

30.1.3 Connection to a JNDI DataSource
If you deploy your Spring Boot application to an Application Server, you might want to configure and manage your DataSource by using your
Application Server’s built-in features and access it by using JNDI.
The spring.datasource.jndi-name property can be used as an alternative to the spring.datasource.url , spring.datasource.username ,
and spring.datasource.password properties to access the DataSource from a specific JNDI location. For example, the following section in
application.properties shows how you can access a JBoss AS defined DataSource :
spring.datasource.jndi-name=java:jboss/datasources/customers

30.2 Using JdbcTemplate
Spring’s JdbcTemplate and NamedParameterJdbcTemplate classes are auto-configured, and you can @Autowire them directly into your own
beans, as shown in the following example:
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Component;
@Component
public class MyBean {
private final JdbcTemplate jdbcTemplate;
@Autowired
public MyBean(JdbcTemplate jdbcTemplate) {
this.jdbcTemplate = jdbcTemplate;
}

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// ...

}

You can customize some properties of the template by using the spring.jdbc.template.* properties, as shown in the following example:
spring.jdbc.template.max-rows=500

The NamedParameterJdbcTemplate reuses the same JdbcTemplate instance behind the scenes. If more than one JdbcTemplate
is defined and no primary candidate exists, the NamedParameterJdbcTemplate is not auto-configured.

30.3 JPA and Spring Data JPA
The Java Persistence API is a standard technology that lets you “map” objects to relational databases. The spring-boot-starter-data-jpa
POM provides a quick way to get started. It provides the following key dependencies:
Hibernate: One of the most popular JPA implementations.
Spring Data JPA: Makes it easy to implement JPA-based repositories.
Spring ORMs: Core ORM support from the Spring Framework.

We do not go into too many details of JPA or Spring Data here. You can follow the “Accessing Data with JPA” guide from spring.io and
read the Spring Data JPA and Hibernate reference documentation.

30.3.1 Entity Classes
Traditionally, JPA “Entity” classes are specified in a persistence.xml file. With Spring Boot, this file is not necessary and “Entity Scanning” is used
instead. By default, all packages below your main configuration class (the one annotated with @EnableAutoConfiguration or
@SpringBootApplication ) are searched.
Any classes annotated with @Entity , @Embeddable , or @MappedSuperclass are considered. A typical entity class resembles the following
example:
package com.example.myapp.domain;
import java.io.Serializable;
import javax.persistence.*;
@Entity
public class City implements Serializable {
@Id
@GeneratedValue
private Long id;
@Column(nullable = false)
private String name;
@Column(nullable = false)
private String state;
// ... additional members, often include @OneToMany mappings
protected City() {
// no-args constructor required by JPA spec
// this one is protected since it shouldn't be used directly
}
public City(String name, String state) {
this.name = name;
this.state = state;
}

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public String getName() {
return this.name;
}
public String getState() {
return this.state;
}
// ... etc

}

You can customize entity scanning locations by using the @EntityScan annotation. See the “Section 84.4, “Separate @Entity
Definitions from Spring Configuration”” how-to.

30.3.2 Spring Data JPA Repositories
Spring Data JPA repositories are interfaces that you can define to access data. JPA queries are created automatically from your method names. For
example, a CityRepository interface might declare a findAllByState(String state) method to find all the cities in a given state.
For more complex queries, you can annotate your method with Spring Data’s Query annotation.
Spring Data repositories usually extend from the Repository or CrudRepository interfaces. If you use auto-configuration, repositories are
searched from the package containing your main configuration class (the one annotated with @EnableAutoConfiguration or
@SpringBootApplication ) down.
The following example shows a typical Spring Data repository interface definition:
package com.example.myapp.domain;
import org.springframework.data.domain.*;
import org.springframework.data.repository.*;
public interface CityRepository extends Repository {
Page findAll(Pageable pageable);
City findByNameAndStateAllIgnoringCase(String name, String state);
}

Spring Data JPA repositories support three different modes of bootstrapping: default, deferred, and lazy. To enable deferred or lazy bootstrapping,
set the spring.data.jpa.repositories.bootstrap-mode to deferred or lazy respectively. When using deferred or lazy bootstrapping, the
auto-configured EntityManagerFactoryBuilder will use the context’s async task executor, if any, as the bootstrap executor.

We have barely scratched the surface of Spring Data JPA. For complete details, see the Spring Data JPA reference documentation.

30.3.3 Creating and Dropping JPA Databases
By default, JPA databases are automatically created only if you use an embedded database (H2, HSQL, or Derby). You can explicitly configure JPA
settings by using spring.jpa.* properties. For example, to create and drop tables you can add the following line to your
application.properties :
spring.jpa.hibernate.ddl-auto=create-drop

Hibernate’s own internal property name for this (if you happen to remember it better) is hibernate.hbm2ddl.auto . You can set it,
along with other Hibernate native properties, by using spring.jpa.properties.* (the prefix is stripped before adding them to the
entity manager). The following line shows an example of setting JPA properties for Hibernate:

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spring.jpa.properties.hibernate.globally_quoted_identifiers=true

The line in the preceding example passes a value of true for the hibernate.globally_quoted_identifiers property to the Hibernate entity
manager.
By default, the DDL execution (or validation) is deferred until the ApplicationContext has started. There is also a spring.jpa.generate-ddl
flag, but it is not used if Hibernate auto-configuration is active, because the ddl-auto settings are more fine-grained.

30.3.4 Open EntityManager in View
If you are running a web application, Spring Boot by default registers OpenEntityManagerInViewInterceptor to apply the “Open EntityManager
in View” pattern, to allow for lazy loading in web views. If you do not want this behavior, you should set spring.jpa.open-in-view to false in
your application.properties .

30.4 Spring Data JDBC
Spring Data includes repository support for JDBC and will automatically generate SQL for the methods on CrudRepository . For more advanced
queries, a @Query annotation is provided.
Spring Boot will auto-configure Spring Data’s JDBC repositories when the necessary dependencies are on the classpath. They can be added to your
project with a single dependency on spring-boot-starter-data-jdbc . If necessary, you can take control of Spring Data JDBC’s configuration by
adding the @EnableJdbcRepositories annotation or a JdbcConfiguration subclass to your application.

For complete details of Spring Data JDBC, please refer to the reference documentation.

30.5 Using H2’s Web Console
The H2 database provides a browser-based console that Spring Boot can auto-configure for you. The console is auto-configured when the following
conditions are met:
You are developing a servlet-based web application.
com.h2database:h2 is on the classpath.
You are using Spring Boot’s developer tools.

If you are not using Spring Boot’s developer tools but would still like to make use of H2’s console, you can configure the
spring.h2.console.enabled property with a value of true .

The H2 console is only intended for use during development, so you should take care to ensure that spring.h2.console.enabled
is not set to true in production.

30.5.1 Changing the H2 Console’s Path
By default, the console is available at /h2-console . You can customize the console’s path by using the spring.h2.console.path property.

30.6 Using jOOQ
Java Object Oriented Querying (jOOQ) is a popular product from Data Geekery which generates Java code from your database and lets you build
type-safe SQL queries through its fluent API. Both the commercial and open source editions can be used with Spring Boot.

30.6.1 Code Generation
In order to use jOOQ type-safe queries, you need to generate Java classes from your database schema. You can follow the instructions in the jOOQ
user manual. If you use the jooq-codegen-maven plugin and you also use the spring-boot-starter-parent “parent POM”, you can safely

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omit the plugin’s  tag. You can also use Spring Boot-defined version variables (such as h2.version ) to declare the plugin’s database
dependency. The following listing shows an example:

org.jooq
jooq-codegen-maven

...



com.h2database
h2
${h2.version}




org.h2.Driver
jdbc:h2:~/yourdatabase


...




30.6.2 Using DSLContext
The fluent API offered by jOOQ is initiated through the org.jooq.DSLContext interface. Spring Boot auto-configures a DSLContext as a Spring
Bean and connects it to your application DataSource . To use the DSLContext , you can @Autowire it, as shown in the following example:
@Component
public class JooqExample implements CommandLineRunner {
private final DSLContext create;
@Autowired
public JooqExample(DSLContext dslContext) {
this.create = dslContext;
}
}

The jOOQ manual tends to use a variable named create to hold the DSLContext .

You can then use the DSLContext to construct your queries, as shown in the following example:
public List authorsBornAfter1980() {
return this.create.selectFrom(AUTHOR)
.where(AUTHOR.DATE_OF_BIRTH.greaterThan(new GregorianCalendar(1980, 0, 1)))
.fetch(AUTHOR.DATE_OF_BIRTH);
}

30.6.3 jOOQ SQL Dialect
Unless the spring.jooq.sql-dialect property has been configured, Spring Boot determines the SQL dialect to use for your datasource. If
Spring Boot could not detect the dialect, it uses DEFAULT .

Spring Boot can only auto-configure dialects supported by the open source version of jOOQ.

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30.6.4 Customizing jOOQ
More advanced customizations can be achieved by defining your own @Bean definitions, which is used when the jOOQ Configuration is
created. You can define beans for the following jOOQ Types:
ConnectionProvider
ExecutorProvider
TransactionProvider
RecordMapperProvider
RecordUnmapperProvider
RecordListenerProvider
ExecuteListenerProvider
VisitListenerProvider
TransactionListenerProvider
You can also create your own org.jooq.Configuration @Bean if you want to take complete control of the jOOQ configuration.

31. Working with NoSQL Technologies
Spring Data provides additional projects that help you access a variety of NoSQL technologies, including: MongoDB, Neo4J, Elasticsearch, Solr,
Redis, Gemfire, Cassandra, Couchbase and LDAP. Spring Boot provides auto-configuration for Redis, MongoDB, Neo4j, Elasticsearch, Solr
Cassandra, Couchbase, and LDAP. You can make use of the other projects, but you must configure them yourself. Refer to the appropriate
reference documentation at projects.spring.io/spring-data.

31.1 Redis
Redis is a cache, message broker, and richly-featured key-value store. Spring Boot offers basic auto-configuration for the Lettuce and Jedis client
libraries and the abstractions on top of them provided by Spring Data Redis.
There is a spring-boot-starter-data-redis “Starter” for collecting the dependencies in a convenient way. By default, it uses Lettuce. That
starter handles both traditional and reactive applications.

we also provide a spring-boot-starter-data-redis-reactive “Starter” for consistency with the other stores with reactive
support.

31.1.1 Connecting to Redis
You can inject an auto-configured RedisConnectionFactory , StringRedisTemplate , or vanilla RedisTemplate instance as you would any
other Spring Bean. By default, the instance tries to connect to a Redis server at localhost:6379 . The following listing shows an example of such
a bean:
@Component
public class MyBean {
private StringRedisTemplate template;
@Autowired
public MyBean(StringRedisTemplate template) {
this.template = template;
}
// ...
}

You can also register an arbitrary number of beans that implement LettuceClientConfigurationBuilderCustomizer for more
advanced customizations. If you use Jedis, JedisClientConfigurationBuilderCustomizer is also available.

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If you add your own @Bean of any of the auto-configured types, it replaces the default (except in the case of RedisTemplate , when the exclusion
is based on the bean name, redisTemplate , not its type). By default, if commons-pool2 is on the classpath, you get a pooled connection factory.

31.2 MongoDB
MongoDB is an open-source NoSQL document database that uses a JSON-like schema instead of traditional table-based relational data. Spring
Boot offers several conveniences for working with MongoDB, including the spring-boot-starter-data-mongodb and
spring-boot-starter-data-mongodb-reactive “Starters”.

31.2.1 Connecting to a MongoDB Database
To access Mongo databases, you can inject an auto-configured org.springframework.data.mongodb.MongoDbFactory . By default, the instance
tries to connect to a MongoDB server at mongodb://localhost/test The following example shows how to connect to a MongoDB database:
import org.springframework.data.mongodb.MongoDbFactory;
import com.mongodb.DB;
@Component
public class MyBean {
private final MongoDbFactory mongo;
@Autowired
public MyBean(MongoDbFactory mongo) {
this.mongo = mongo;
}
// ...
public void example() {
DB db = mongo.getDb();
// ...
}
}

You can set the spring.data.mongodb.uri property to change the URL and configure additional settings such as the replica set, as shown in the
following example:
spring.data.mongodb.uri=mongodb://user:secret@mongo1.example.com:12345,mongo2.example.com:23456/test

Alternatively, as long as you use Mongo 2.x, you can specify a host / port . For example, you might declare the following settings in your
application.properties :
spring.data.mongodb.host=mongoserver
spring.data.mongodb.port=27017

If you have defined your own MongoClient , it will be used to auto-configure a suitable MongoDbFactory . Both com.mongodb.MongoClient and
com.mongodb.client.MongoClient are supported.

If you use the Mongo 3.0 Java driver, spring.data.mongodb.host and spring.data.mongodb.port are not supported. In such
cases, spring.data.mongodb.uri should be used to provide all of the configuration.

If spring.data.mongodb.port is not specified, the default of 27017 is used. You could delete this line from the example shown
earlier.

If you do not use Spring Data Mongo, you can inject com.mongodb.MongoClient beans instead of using MongoDbFactory . If you
want to take complete control of establishing the MongoDB connection, you can also declare your own MongoDbFactory or
MongoClient bean.
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If you are using the reactive driver, Netty is required for SSL. The auto-configuration configures this factory automatically if Netty is
available and the factory to use hasn’t been customized already.

31.2.2 MongoTemplate
Spring Data MongoDB provides a MongoTemplate class that is very similar in its design to Spring’s JdbcTemplate . As with JdbcTemplate ,
Spring Boot auto-configures a bean for you to inject the template, as follows:
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.stereotype.Component;
@Component
public class MyBean {
private final MongoTemplate mongoTemplate;
@Autowired
public MyBean(MongoTemplate mongoTemplate) {
this.mongoTemplate = mongoTemplate;
}
// ...
}

See the MongoOperations Javadoc for complete details.

31.2.3 Spring Data MongoDB Repositories
Spring Data includes repository support for MongoDB. As with the JPA repositories discussed earlier, the basic principle is that queries are
constructed automatically, based on method names.
In fact, both Spring Data JPA and Spring Data MongoDB share the same common infrastructure. You could take the JPA example from earlier and,
assuming that City is now a Mongo data class rather than a JPA @Entity , it works in the same way, as shown in the following example:
package com.example.myapp.domain;
import org.springframework.data.domain.*;
import org.springframework.data.repository.*;
public interface CityRepository extends Repository {
Page findAll(Pageable pageable);
City findByNameAndStateAllIgnoringCase(String name, String state);
}

You can customize document scanning locations by using the @EntityScan annotation.

For complete details of Spring Data MongoDB, including its rich object mapping technologies, refer to its reference documentation.

31.2.4 Embedded Mongo
Spring Boot offers auto-configuration for Embedded Mongo. To use it in your Spring Boot application, add a dependency on
de.flapdoodle.embed:de.flapdoodle.embed.mongo .

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The port that Mongo listens on can be configured by setting the spring.data.mongodb.port property. To use a randomly allocated free port, use
a value of 0. The MongoClient created by MongoAutoConfiguration is automatically configured to use the randomly allocated port.

If you do not configure a custom port, the embedded support uses a random port (rather than 27017) by default.

If you have SLF4J on the classpath, the output produced by Mongo is automatically routed to a logger named
org.springframework.boot.autoconfigure.mongo.embedded.EmbeddedMongo .
You can declare your own IMongodConfig and IRuntimeConfig beans to take control of the Mongo instance’s configuration and logging routing.

31.3 Neo4j
Neo4j is an open-source NoSQL graph database that uses a rich data model of nodes connected by first class relationships, which is better suited
for connected big data than traditional RDBMS approaches. Spring Boot offers several conveniences for working with Neo4j, including the
spring-boot-starter-data-neo4j “Starter”.

31.3.1 Connecting to a Neo4j Database
To access a Neo4j server, you can inject an auto-configured org.neo4j.ogm.session.Session . By default, the instance tries to connect to a
Neo4j server at localhost:7687 using the Bolt protocol. The following example shows how to inject a Neo4j Session :
@Component
public class MyBean {
private final Session session;
@Autowired
public MyBean(Session session) {
this.session = session;
}
// ...
}

You can configure the uri and credentials to use by setting the spring.data.neo4j.* properties, as shown in the following example:
spring.data.neo4j.uri=bolt://my-server:7687
spring.data.neo4j.username=neo4j
spring.data.neo4j.password=secret

You can take full control over the session creation by adding a org.neo4j.ogm.config.Configuration @Bean . Also, adding a @Bean of type
SessionFactory disables the auto-configuration and gives you full control.

31.3.2 Using the Embedded Mode
If you add org.neo4j:neo4j-ogm-embedded-driver to the dependencies of your application, Spring Boot automatically configures an in-process
embedded instance of Neo4j that does not persist any data when your application shuts down.

As the embedded Neo4j OGM driver does not provide the Neo4j kernel itself, you have to declare org.neo4j:neo4j as dependency
yourself. Refer to the Neo4j OGM documentation for a list of compatible versions.

The embedded driver takes precedence over the other drivers when there are multiple drivers on the classpath. You can explicitly disable the
embedded mode by setting spring.data.neo4j.embedded.enabled=false .
Data Neo4j Tests automatically make use of an embedded Neo4j instance if the embedded driver and Neo4j kernel are on the classpath as
described above.

You can enable persistence for the embedded mode by providing a path to a database file in your configuration, e.g.
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spring.data.neo4j.uri=file://var/tmp/graph.db .

31.3.3 Neo4jSession
By default, if you are running a web application, the session is bound to the thread for the entire processing of the request (that is, it uses the "Open
Session in View" pattern). If you do not want this behavior, add the following line to your application.properties file:
spring.data.neo4j.open-in-view=false

31.3.4 Spring Data Neo4j Repositories
Spring Data includes repository support for Neo4j.
Spring Data Neo4j shares the common infrastructure with Spring Data JPA as many other Spring Data modules do. You could take the JPA example
from earlier and define City as Neo4j OGM @NodeEntity rather than JPA @Entity and the repository abstraction works in the same way, as
shown in the following example:
package com.example.myapp.domain;
import java.util.Optional;
import org.springframework.data.neo4j.repository.*;
public interface CityRepository extends Neo4jRepository {
Optional findOneByNameAndState(String name, String state);
}

The spring-boot-starter-data-neo4j “Starter” enables the repository support as well as transaction management. You can customize the
locations to look for repositories and entities by using @EnableNeo4jRepositories and @EntityScan respectively on a @Configuration -bean.

For complete details of Spring Data Neo4j, including its object mapping technologies, refer to the reference documentation.

31.4 Gemfire
Spring Data Gemfire provides convenient Spring-friendly tools for accessing the Pivotal Gemfire data management platform. There is a
spring-boot-starter-data-gemfire “Starter” for collecting the dependencies in a convenient way. There is currently no auto-configuration
support for Gemfire, but you can enable Spring Data Repositories with a single annotation: @EnableGemfireRepositories .

31.5 Solr
Apache Solr is a search engine. Spring Boot offers basic auto-configuration for the Solr 5 client library and the abstractions on top of it provided by
Spring Data Solr. There is a spring-boot-starter-data-solr “Starter” for collecting the dependencies in a convenient way.

31.5.1 Connecting to Solr
You can inject an auto-configured SolrClient instance as you would any other Spring bean. By default, the instance tries to connect to a server at
localhost:8983/solr . The following example shows how to inject a Solr bean:
@Component
public class MyBean {
private SolrClient solr;
@Autowired
public MyBean(SolrClient solr) {
this.solr = solr;
}

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// ...

}

If you add your own @Bean of type SolrClient , it replaces the default.

31.5.2 Spring Data Solr Repositories
Spring Data includes repository support for Apache Solr. As with the JPA repositories discussed earlier, the basic principle is that queries are
automatically constructed for \ you based on method names.
In fact, both Spring Data JPA and Spring Data Solr share the same common infrastructure. You could take the JPA example from earlier and,
assuming that City is now a @SolrDocument class rather than a JPA @Entity , it works in the same way.

For complete details of Spring Data Solr, refer to the reference documentation.

31.6 Elasticsearch
Elasticsearch is an open source, distributed, RESTful search and analytics engine. Spring Boot offers basic auto-configuration for Elasticsearch.
Spring Boot supports several HTTP clients:
The official Java "Low Level" and "High Level" REST clients
Jest
The transport client is still being used by Spring Data Elasticsearch, which you can start using with the
spring-boot-starter-data-elasticsearch “Starter”.

31.6.1 Connecting to Elasticsearch by REST clients
Elasticsearch ships two different REST clients that you can use to query a cluster: the "Low Level" client and the "High Level" client.
If you have the org.elasticsearch.client:elasticsearch-rest-client dependency on the classpath, Spring Boot will auto-configure and
register a RestClient bean that by default targets localhost:9200 . You can further tune how RestClient is configured, as shown in the
following example:
spring.elasticsearch.rest.uris=http://search.example.com:9200
spring.elasticsearch.rest.username=user
spring.elasticsearch.rest.password=secret

You can also register an arbitrary number of beans that implement RestClientBuilderCustomizer for more advanced customizations. To take
full control over the registration, define a RestClient bean.
If you have the org.elasticsearch.client:elasticsearch-rest-high-level-client dependency on the classpath, Spring Boot will autoconfigure a RestHighLevelClient , which wraps any existing RestClient bean, reusing its HTTP configuration.

31.6.2 Connecting to Elasticsearch by Using Jest
If you have Jest on the classpath, you can inject an auto-configured JestClient that by default targets localhost:9200 . You can further tune
how the client is configured, as shown in the following example:
spring.elasticsearch.jest.uris=http://search.example.com:9200
spring.elasticsearch.jest.read-timeout=10000
spring.elasticsearch.jest.username=user
spring.elasticsearch.jest.password=secret

You can also register an arbitrary number of beans that implement HttpClientConfigBuilderCustomizer for more advanced customizations.
The following example tunes additional HTTP settings:
static class HttpSettingsCustomizer implements HttpClientConfigBuilderCustomizer {

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@Override
public void customize(HttpClientConfig.Builder builder) {
builder.maxTotalConnection(100).defaultMaxTotalConnectionPerRoute(5);
}

}

To take full control over the registration, define a JestClient bean.

31.6.3 Connecting to Elasticsearch by Using Spring Data
To connect to Elasticsearch, you must provide the address of one or more cluster nodes. The address can be specified by setting the
spring.data.elasticsearch.cluster-nodes property to a comma-separated host:port list. With this configuration in place, an
ElasticsearchTemplate or TransportClient can be injected like any other Spring bean, as shown in the following example:
spring.data.elasticsearch.cluster-nodes=localhost:9300
@Component
public class MyBean {
private final ElasticsearchTemplate template;
public MyBean(ElasticsearchTemplate template) {
this.template = template;
}
// ...
}

If you add your own ElasticsearchTemplate or TransportClient @Bean , it replaces the default.

31.6.4 Spring Data Elasticsearch Repositories
Spring Data includes repository support for Elasticsearch. As with the JPA repositories discussed earlier, the basic principle is that queries are
constructed for you automatically based on method names.
In fact, both Spring Data JPA and Spring Data Elasticsearch share the same common infrastructure. You could take the JPA example from earlier
and, assuming that City is now an Elasticsearch @Document class rather than a JPA @Entity , it works in the same way.

For complete details of Spring Data Elasticsearch, refer to the reference documentation.

31.7 Cassandra
Cassandra is an open source, distributed database management system designed to handle large amounts of data across many commodity
servers. Spring Boot offers auto-configuration for Cassandra and the abstractions on top of it provided by Spring Data Cassandra. There is a
spring-boot-starter-data-cassandra “Starter” for collecting the dependencies in a convenient way.

31.7.1 Connecting to Cassandra
You can inject an auto-configured CassandraTemplate or a Cassandra Session instance as you would with any other Spring Bean. The
spring.data.cassandra.* properties can be used to customize the connection. Generally, you provide keyspace-name and contact-points
properties, as shown in the following example:
spring.data.cassandra.keyspace-name=mykeyspace
spring.data.cassandra.contact-points=cassandrahost1,cassandrahost2

You can also register an arbitrary number of beans that implement ClusterBuilderCustomizer for more advanced customizations.
The following code listing shows how to inject a Cassandra bean:
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@Component
public class MyBean {
private CassandraTemplate template;
@Autowired
public MyBean(CassandraTemplate template) {
this.template = template;
}
// ...
}

If you add your own @Bean of type CassandraTemplate , it replaces the default.

31.7.2 Spring Data Cassandra Repositories
Spring Data includes basic repository support for Cassandra. Currently, this is more limited than the JPA repositories discussed earlier and needs to
annotate finder methods with @Query .

For complete details of Spring Data Cassandra, refer to the reference documentation.

31.8 Couchbase
Couchbase is an open-source, distributed, multi-model NoSQL document-oriented database that is optimized for interactive applications. Spring
Boot offers auto-configuration for Couchbase and the abstractions on top of it provided by Spring Data Couchbase. There are
spring-boot-starter-data-couchbase and spring-boot-starter-data-couchbase-reactive “Starters” for collecting the dependencies in
a convenient way.

31.8.1 Connecting to Couchbase
You can get a Bucket and Cluster by adding the Couchbase SDK and some configuration. The spring.couchbase.* properties can be used
to customize the connection. Generally, you provide the bootstrap hosts, bucket name, and password, as shown in the following example:
spring.couchbase.bootstrap-hosts=my-host-1,192.168.1.123
spring.couchbase.bucket.name=my-bucket
spring.couchbase.bucket.password=secret

You need to provide at least the bootstrap host(s), in which case the bucket name is default and the password is an empty String.
Alternatively, you can define your own org.springframework.data.couchbase.config.CouchbaseConfigurer @Bean to take
control over the whole configuration.

It is also possible to customize some of the CouchbaseEnvironment settings. For instance, the following configuration changes the timeout to use
to open a new Bucket and enables SSL support:
spring.couchbase.env.timeouts.connect=3000
spring.couchbase.env.ssl.key-store=/location/of/keystore.jks
spring.couchbase.env.ssl.key-store-password=secret

Check the spring.couchbase.env.* properties for more details.

31.8.2 Spring Data Couchbase Repositories
Spring Data includes repository support for Couchbase. For complete details of Spring Data Couchbase, refer to the reference documentation.
You can inject an auto-configured CouchbaseTemplate instance as you would with any other Spring Bean, provided a default
CouchbaseConfigurer is available (which happens when you enable Couchbase support, as explained earlier).
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The following examples shows how to inject a Couchbase bean:
@Component
public class MyBean {
private final CouchbaseTemplate template;
@Autowired
public MyBean(CouchbaseTemplate template) {
this.template = template;
}
// ...
}

There are a few beans that you can define in your own configuration to override those provided by the auto-configuration:
A CouchbaseTemplate @Bean with a name of couchbaseTemplate .
An IndexManager @Bean with a name of couchbaseIndexManager .
A CustomConversions @Bean with a name of couchbaseCustomConversions .
To avoid hard-coding those names in your own config, you can reuse BeanNames provided by Spring Data Couchbase. For instance, you can
customize the converters to use, as follows:
@Configuration
public class SomeConfiguration {
@Bean(BeanNames.COUCHBASE_CUSTOM_CONVERSIONS)
public CustomConversions myCustomConversions() {
return new CustomConversions(...);
}
// ...
}

If you want to fully bypass the auto-configuration for Spring Data Couchbase, provide your own implementation of
org.springframework.data.couchbase.config.AbstractCouchbaseDataConfiguration .

31.9 LDAP
LDAP (Lightweight Directory Access Protocol) is an open, vendor-neutral, industry standard application protocol for accessing and maintaining
distributed directory information services over an IP network. Spring Boot offers auto-configuration for any compliant LDAP server as well as support
for the embedded in-memory LDAP server from UnboundID.
LDAP abstractions are provided by Spring Data LDAP. There is a spring-boot-starter-data-ldap “Starter” for collecting the dependencies in a
convenient way.

31.9.1 Connecting to an LDAP Server
To connect to an LDAP server, make sure you declare a dependency on the spring-boot-starter-data-ldap “Starter” or spring-ldap-core
and then declare the URLs of your server in your application.properties, as shown in the following example:
spring.ldap.urls=ldap://myserver:1235
spring.ldap.username=admin
spring.ldap.password=secret

If you need to customize connection settings, you can use the spring.ldap.base and spring.ldap.base-environment properties.
An LdapContextSource is auto-configured based on these settings. If you need to customize it, for instance to use a PooledContextSource , you
can still inject the auto-configured LdapContextSource . Make sure to flag your customized ContextSource as @Primary so that the autoconfigured LdapTemplate uses it.
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31.9.2 Spring Data LDAP Repositories
Spring Data includes repository support for LDAP. For complete details of Spring Data LDAP, refer to the reference documentation.
You can also inject an auto-configured LdapTemplate instance as you would with any other Spring Bean, as shown in the following example:
@Component
public class MyBean {
private final LdapTemplate template;
@Autowired
public MyBean(LdapTemplate template) {
this.template = template;
}
// ...
}

31.9.3 Embedded In-memory LDAP Server
For testing purposes, Spring Boot supports auto-configuration of an in-memory LDAP server from UnboundID. To configure the server, add a
dependency to com.unboundid:unboundid-ldapsdk and declare a base-dn property, as follows:
spring.ldap.embedded.base-dn=dc=spring,dc=io

It is possible to define multiple base-dn values, however, since distinguished names usually contain commas, they must be defined
using the correct notation.
In yaml files, you can use the yaml list notation:
spring.ldap.embedded.base-dn:
- dc=spring,dc=io
- dc=pivotal,dc=io

In properties files, you must include the index as part of the property name:
spring.ldap.embedded.base-dn[0]=dc=spring,dc=io
spring.ldap.embedded.base-dn[1]=dc=pivotal,dc=io

By default, the server starts on a random port and triggers the regular LDAP support. There is no need to specify a spring.ldap.urls property.
If there is a schema.ldif file on your classpath, it is used to initialize the server. If you want to load the initialization script from a different resource,
you can also use the spring.ldap.embedded.ldif property.
By default, a standard schema is used to validate LDIF files. You can turn off validation altogether by setting the
spring.ldap.embedded.validation.enabled property. If you have custom attributes, you can use
spring.ldap.embedded.validation.schema to define your custom attribute types or object classes.

31.10 InfluxDB
InfluxDB is an open-source time series database optimized for fast, high-availability storage and retrieval of time series data in fields such as
operations monitoring, application metrics, Internet-of-Things sensor data, and real-time analytics.

31.10.1 Connecting to InfluxDB
Spring Boot auto-configures an InfluxDB instance, provided the influxdb-java client is on the classpath and the URL of the database is set, as
shown in the following example:
spring.influx.url=http://172.0.0.1:8086

If the connection to InfluxDB requires a user and password, you can set the spring.influx.user and spring.influx.password properties
accordingly.
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InfluxDB relies on OkHttp. If you need to tune the http client InfluxDB uses behind the scenes, you can register an
InfluxDbOkHttpClientBuilderProvider bean.

32. Caching
The Spring Framework provides support for transparently adding caching to an application. At its core, the abstraction applies caching to methods,
thus reducing the number of executions based on the information available in the cache. The caching logic is applied transparently, without any
interference to the invoker. Spring Boot auto-configures the cache infrastructure as long as caching support is enabled via the @EnableCaching
annotation.

Check the relevant section of the Spring Framework reference for more details.

In a nutshell, adding caching to an operation of your service is as easy as adding the relevant annotation to its method, as shown in the following
example:
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Component;
@Component
public class MathService {
@Cacheable("piDecimals")
public int computePiDecimal(int i) {
// ...
}
}

This example demonstrates the use of caching on a potentially costly operation. Before invoking computePiDecimal , the abstraction looks for an
entry in the piDecimals cache that matches the i argument. If an entry is found, the content in the cache is immediately returned to the caller,
and the method is not invoked. Otherwise, the method is invoked, and the cache is updated before returning the value.
Caution
You can also use the standard JSR-107 (JCache) annotations (such as @CacheResult ) transparently. However, we
strongly advise you to not mix and match the Spring Cache and JCache annotations.

If you do not add any specific cache library, Spring Boot auto-configures a simple provider that uses concurrent maps in memory. When a cache is
required (such as piDecimals in the preceding example), this provider creates it for you. The simple provider is not really recommended for
production usage, but it is great for getting started and making sure that you understand the features. When you have made up your mind about the
cache provider to use, please make sure to read its documentation to figure out how to configure the caches that your application uses. Nearly all
providers require you to explicitly configure every cache that you use in the application. Some offer a way to customize the default caches defined
by the spring.cache.cache-names property.

It is also possible to transparently update or evict data from the cache.

32.1 Supported Cache Providers
The cache abstraction does not provide an actual store and relies on abstraction materialized by the org.springframework.cache.Cache and
org.springframework.cache.CacheManager interfaces.
If you have not defined a bean of type CacheManager or a CacheResolver named cacheResolver (see CachingConfigurer ), Spring Boot
tries to detect the following providers (in the indicated order):
1. Generic
2. JCache (JSR-107) (EhCache 3, Hazelcast, Infinispan, and others)
3. EhCache 2.x
4. Hazelcast
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5. Infinispan
6. Couchbase
7. Redis
8. Caffeine
9. Simple

It is also possible to force a particular cache provider by setting the spring.cache.type property. Use this property if you need to
disable caching altogether in certain environment (such as tests).

Use the spring-boot-starter-cache “Starter” to quickly add basic caching dependencies. The starter brings in
spring-context-support . If you add dependencies manually, you must include spring-context-support in order to use the
JCache, EhCache 2.x, or Guava support.

If the CacheManager is auto-configured by Spring Boot, you can further tune its configuration before it is fully initialized by exposing a bean that
implements the CacheManagerCustomizer interface. The following example sets a flag to say that null values should be passed down to the
underlying map:
@Bean
public CacheManagerCustomizer cacheManagerCustomizer() {
return new CacheManagerCustomizer() {
@Override
public void customize(ConcurrentMapCacheManager cacheManager) {
cacheManager.setAllowNullValues(false);
}
};
}

In the preceding example, an auto-configured ConcurrentMapCacheManager is expected. If that is not the case (either you provided
your own config or a different cache provider was auto-configured), the customizer is not invoked at all. You can have as many
customizers as you want, and you can also order them by using @Order or Ordered .

32.1.1 Generic
Generic caching is used if the context defines at least one org.springframework.cache.Cache bean. A CacheManager wrapping all beans of
that type is created.

32.1.2 JCache (JSR-107)
JCache is bootstrapped through the presence of a javax.cache.spi.CachingProvider on the classpath (that is, a JSR-107 compliant caching
library exists on the classpath), and the JCacheCacheManager is provided by the spring-boot-starter-cache “Starter”. Various compliant
libraries are available, and Spring Boot provides dependency management for Ehcache 3, Hazelcast, and Infinispan. Any other compliant library can
be added as well.
It might happen that more than one provider is present, in which case the provider must be explicitly specified. Even if the JSR-107 standard does
not enforce a standardized way to define the location of the configuration file, Spring Boot does its best to accommodate setting a cache with
implementation details, as shown in the following example:
# Only necessary if more than one provider is present
spring.cache.jcache.provider=com.acme.MyCachingProvider
spring.cache.jcache.config=classpath:acme.xml

When a cache library offers both a native implementation and JSR-107 support, Spring Boot prefers the JSR-107 support, so that the
same features are available if you switch to a different JSR-107 implementation.

Spring Boot has general support for Hazelcast. If a single HazelcastInstance is available, it is automatically reused for the
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CacheManager as well, unless the spring.cache.jcache.config property is specified.

There are two ways to customize the underlying javax.cache.cacheManager :
Caches can be created on startup by setting the spring.cache.cache-names property. If a custom
javax.cache.configuration.Configuration bean is defined, it is used to customize them.
org.springframework.boot.autoconfigure.cache.JCacheManagerCustomizer beans are invoked with the reference of the
CacheManager for full customization.

If a standard javax.cache.CacheManager bean is defined, it is wrapped automatically in an
org.springframework.cache.CacheManager implementation that the abstraction expects. No further customization is applied to it.

32.1.3 EhCache 2.x
EhCache 2.x is used if a file named ehcache.xml can be found at the root of the classpath. If EhCache 2.x is found, the EhCacheCacheManager
provided by the spring-boot-starter-cache “Starter” is used to bootstrap the cache manager. An alternate configuration file can be provided as
well, as shown in the following example:
spring.cache.ehcache.config=classpath:config/another-config.xml

32.1.4 Hazelcast
Spring Boot has general support for Hazelcast. If a HazelcastInstance has been auto-configured, it is automatically wrapped in a
CacheManager .

32.1.5 Infinispan
Infinispan has no default configuration file location, so it must be specified explicitly. Otherwise, the default bootstrap is used.
spring.cache.infinispan.config=infinispan.xml

Caches can be created on startup by setting the spring.cache.cache-names property. If a custom ConfigurationBuilder bean is defined, it is
used to customize the caches.

The support of Infinispan in Spring Boot is restricted to the embedded mode and is quite basic. If you want more options, you should
use the official Infinispan Spring Boot starter instead. See Infinispan’s documentation for more details.

32.1.6 Couchbase
If the Couchbase Java client and the couchbase-spring-cache implementation are available and Couchbase is configured, a
CouchbaseCacheManager is auto-configured. It is also possible to create additional caches on startup by setting the spring.cache.cache-names
property. These caches operate on the Bucket that was auto-configured. You can also create additional caches on another Bucket by using the
customizer. Assume you need two caches ( cache1 and cache2 ) on the "main" Bucket and one ( cache3 ) cache with a custom time to live of 2
seconds on the “another” Bucket . You can create the first two caches through configuration, as follows:
spring.cache.cache-names=cache1,cache2

Then you can define a @Configuration class to configure the extra Bucket and the cache3 cache, as follows:
@Configuration
public class CouchbaseCacheConfiguration {
private final Cluster cluster;
public CouchbaseCacheConfiguration(Cluster cluster) {
this.cluster = cluster;
}

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@Bean
public Bucket anotherBucket() {
return this.cluster.openBucket("another", "secret");
}
@Bean
public CacheManagerCustomizer cacheManagerCustomizer() {
return c -> {
c.prepareCache("cache3", CacheBuilder.newInstance(anotherBucket())
.withExpiration(2));
};
}

}

This sample configuration reuses the Cluster that was created through auto-configuration.

32.1.7 Redis
If Redis is available and configured, a RedisCacheManager is auto-configured. It is possible to create additional caches on startup by setting the
spring.cache.cache-names property and cache defaults can be configured by using spring.cache.redis.* properties. For instance, the
following configuration creates cache1 and cache2 caches with a time to live of 10 minutes:
spring.cache.cache-names=cache1,cache2
spring.cache.redis.time-to-live=600000

By default, a key prefix is added so that, if two separate caches use the same key, Redis does not have overlapping keys and cannot
return invalid values. We strongly recommend keeping this setting enabled if you create your own RedisCacheManager .

You can take full control of the configuration by adding a RedisCacheConfiguration @Bean of your own. This can be useful if
you’re looking for customizing the serialization strategy.

32.1.8 Caffeine
Caffeine is a Java 8 rewrite of Guava’s cache that supersedes support for Guava. If Caffeine is present, a CaffeineCacheManager (provided by
the spring-boot-starter-cache “Starter”) is auto-configured. Caches can be created on startup by setting the spring.cache.cache-names
property and can be customized by one of the following (in the indicated order):
1. A cache spec defined by spring.cache.caffeine.spec
2. A com.github.benmanes.caffeine.cache.CaffeineSpec bean is defined
3. A com.github.benmanes.caffeine.cache.Caffeine bean is defined
For instance, the following configuration creates cache1 and cache2 caches with a maximum size of 500 and a time to live of 10 minutes
spring.cache.cache-names=cache1,cache2
spring.cache.caffeine.spec=maximumSize=500,expireAfterAccess=600s

If a com.github.benmanes.caffeine.cache.CacheLoader bean is defined, it is automatically associated to the CaffeineCacheManager . Since
the CacheLoader is going to be associated with all caches managed by the cache manager, it must be defined as
CacheLoader . The auto-configuration ignores any other generic type.

32.1.9 Simple
If none of the other providers can be found, a simple implementation using a ConcurrentHashMap as the cache store is configured. This is the
default if no caching library is present in your application. By default, caches are created as needed, but you can restrict the list of available caches
by setting the cache-names property. For instance, if you want only cache1 and cache2 caches, set the cache-names property as follows:
spring.cache.cache-names=cache1,cache2

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If you do so and your application uses a cache not listed, then it fails at runtime when the cache is needed, but not on startup. This is similar to the
way the "real" cache providers behave if you use an undeclared cache.

32.1.10 None
When @EnableCaching is present in your configuration, a suitable cache configuration is expected as well. If you need to disable caching
altogether in certain environments, force the cache type to none to use a no-op implementation, as shown in the following example:
spring.cache.type=none

33. Messaging
The Spring Framework provides extensive support for integrating with messaging systems, from simplified use of the JMS API using JmsTemplate
to a complete infrastructure to receive messages asynchronously. Spring AMQP provides a similar feature set for the Advanced Message Queuing
Protocol. Spring Boot also provides auto-configuration options for RabbitTemplate and RabbitMQ. Spring WebSocket natively includes support for
STOMP messaging, and Spring Boot has support for that through starters and a small amount of auto-configuration. Spring Boot also has support
for Apache Kafka.

33.1 JMS
The javax.jms.ConnectionFactory interface provides a standard method of creating a javax.jms.Connection for interacting with a JMS
broker. Although Spring needs a ConnectionFactory to work with JMS, you generally need not use it directly yourself and can instead rely on
higher level messaging abstractions. (See the relevant section of the Spring Framework reference documentation for details.) Spring Boot also autoconfigures the necessary infrastructure to send and receive messages.

33.1.1 ActiveMQ Support
When ActiveMQ is available on the classpath, Spring Boot can also configure a ConnectionFactory . If the broker is present, an embedded broker
is automatically started and configured (provided no broker URL is specified through configuration).

If you use spring-boot-starter-activemq , the necessary dependencies to connect or embed an ActiveMQ instance are provided,
as is the Spring infrastructure to integrate with JMS.

ActiveMQ configuration is controlled by external configuration properties in spring.activemq.* . For example, you might declare the following
section in application.properties :
spring.activemq.broker-url=tcp://192.168.1.210:9876
spring.activemq.user=admin
spring.activemq.password=secret

By default, a CachingConnectionFactory wraps the native ConnectionFactory with sensible settings that you can control by external
configuration properties in spring.jms.* :
spring.jms.cache.session-cache-size=5

If you’d rather use native pooling, you can do so by adding a dependency to org.messaginghub:pooled-jms and configuring the
JmsPoolConnectionFactory accordingly, as shown in the following example:
spring.activemq.pool.enabled=true
spring.activemq.pool.max-connections=50

See ActiveMQProperties for more of the supported options. You can also register an arbitrary number of beans that implement
ActiveMQConnectionFactoryCustomizer for more advanced customizations.

By default, ActiveMQ creates a destination if it does not yet exist so that destinations are resolved against their provided names.

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33.1.2 Artemis Support
Spring Boot can auto-configure a ConnectionFactory when it detects that Artemis is available on the classpath. If the broker is present, an
embedded broker is automatically started and configured (unless the mode property has been explicitly set). The supported modes are embedded
(to make explicit that an embedded broker is required and that an error should occur if the broker is not available on the classpath) and native (to
connect to a broker using the netty transport protocol). When the latter is configured, Spring Boot configures a ConnectionFactory that
connects to a broker running on the local machine with the default settings.

If you use spring-boot-starter-artemis , the necessary dependencies to connect to an existing Artemis instance are provided, as
well as the Spring infrastructure to integrate with JMS. Adding org.apache.activemq:artemis-jms-server to your application lets
you use embedded mode.

Artemis configuration is controlled by external configuration properties in spring.artemis.* . For example, you might declare the following section
in application.properties :
spring.artemis.mode=native
spring.artemis.host=192.168.1.210
spring.artemis.port=9876
spring.artemis.user=admin
spring.artemis.password=secret

When embedding the broker, you can choose if you want to enable persistence and list the destinations that should be made available. These can
be specified as a comma-separated list to create them with the default options, or you can define bean(s) of type
org.apache.activemq.artemis.jms.server.config.JMSQueueConfiguration or
org.apache.activemq.artemis.jms.server.config.TopicConfiguration , for advanced queue and topic configurations, respectively.
By default, a CachingConnectionFactory wraps the native ConnectionFactory with sensible settings that you can control by external
configuration properties in spring.jms.* :
spring.jms.cache.session-cache-size=5

If you’d rather use native pooling, you can do so by adding a dependency to org.messaginghub:pooled-jms and configuring the
JmsPoolConnectionFactory accordingly, as shown in the following example:
spring.artemis.pool.enabled=true
spring.artemis.pool.max-connections=50

See ArtemisProperties for more supported options.
No JNDI lookup is involved, and destinations are resolved against their names, using either the name attribute in the Artemis configuration or the
names provided through configuration.

33.1.3 Using a JNDI ConnectionFactory
If you are running your application in an application server, Spring Boot tries to locate a JMS ConnectionFactory by using JNDI. By default, the
java:/JmsXA and java:/XAConnectionFactory location are checked. You can use the spring.jms.jndi-name property if you need to specify
an alternative location, as shown in the following example:
spring.jms.jndi-name=java:/MyConnectionFactory

33.1.4 Sending a Message
Spring’s JmsTemplate is auto-configured, and you can autowire it directly into your own beans, as shown in the following example:
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jms.core.JmsTemplate;
import org.springframework.stereotype.Component;
@Component
public class MyBean {

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private final JmsTemplate jmsTemplate;
@Autowired
public MyBean(JmsTemplate jmsTemplate) {
this.jmsTemplate = jmsTemplate;
}
// ...

}

JmsMessagingTemplate can be injected in a similar manner. If a DestinationResolver or a MessageConverter bean is defined,
it is associated automatically to the auto-configured JmsTemplate .

33.1.5 Receiving a Message
When the JMS infrastructure is present, any bean can be annotated with @JmsListener to create a listener endpoint. If no
JmsListenerContainerFactory has been defined, a default one is configured automatically. If a DestinationResolver or a
MessageConverter beans is defined, it is associated automatically to the default factory.
By default, the default factory is transactional. If you run in an infrastructure where a JtaTransactionManager is present, it is associated to the
listener container by default. If not, the sessionTransacted flag is enabled. In that latter scenario, you can associate your local data store
transaction to the processing of an incoming message by adding @Transactional on your listener method (or a delegate thereof). This ensures
that the incoming message is acknowledged, once the local transaction has completed. This also includes sending response messages that have
been performed on the same JMS session.
The following component creates a listener endpoint on the someQueue destination:
@Component
public class MyBean {
@JmsListener(destination = "someQueue")
public void processMessage(String content) {
// ...
}
}

See the Javadoc of @EnableJms for more details.

If you need to create more JmsListenerContainerFactory instances or if you want to override the default, Spring Boot provides a
DefaultJmsListenerContainerFactoryConfigurer that you can use to initialize a DefaultJmsListenerContainerFactory with the same
settings as the one that is auto-configured.
For instance, the following example exposes another factory that uses a specific MessageConverter :
@Configuration
static class JmsConfiguration {
@Bean
public DefaultJmsListenerContainerFactory myFactory(
DefaultJmsListenerContainerFactoryConfigurer configurer) {
DefaultJmsListenerContainerFactory factory =
new DefaultJmsListenerContainerFactory();
configurer.configure(factory, connectionFactory());
factory.setMessageConverter(myMessageConverter());
return factory;
}
}

Then you can use the factory in any @JmsListener -annotated method as follows:
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@Component
public class MyBean {
@JmsListener(destination = "someQueue", containerFactory="myFactory")
public void processMessage(String content) {
// ...
}
}

33.2 AMQP
The Advanced Message Queuing Protocol (AMQP) is a platform-neutral, wire-level protocol for message-oriented middleware. The Spring AMQP
project applies core Spring concepts to the development of AMQP-based messaging solutions. Spring Boot offers several conveniences for working
with AMQP through RabbitMQ, including the spring-boot-starter-amqp “Starter”.

33.2.1 RabbitMQ support
RabbitMQ is a lightweight, reliable, scalable, and portable message broker based on the AMQP protocol. Spring uses RabbitMQ to communicate
through the AMQP protocol.
RabbitMQ configuration is controlled by external configuration properties in spring.rabbitmq.* . For example, you might declare the following
section in application.properties :
spring.rabbitmq.host=localhost
spring.rabbitmq.port=5672
spring.rabbitmq.username=admin
spring.rabbitmq.password=secret

If a ConnectionNameStrategy bean exists in the context, it will be automatically used to name connections created by the auto-configured
ConnectionFactory . See RabbitProperties for more of the supported options.

See Understanding AMQP, the protocol used by RabbitMQ for more details.

33.2.2 Sending a Message
Spring’s AmqpTemplate and AmqpAdmin are auto-configured, and you can autowire them directly into your own beans, as shown in the following
example:
import
import
import
import

org.springframework.amqp.core.AmqpAdmin;
org.springframework.amqp.core.AmqpTemplate;
org.springframework.beans.factory.annotation.Autowired;
org.springframework.stereotype.Component;

@Component
public class MyBean {
private final AmqpAdmin amqpAdmin;
private final AmqpTemplate amqpTemplate;
@Autowired
public MyBean(AmqpAdmin amqpAdmin, AmqpTemplate amqpTemplate) {
this.amqpAdmin = amqpAdmin;
this.amqpTemplate = amqpTemplate;
}
// ...
}

RabbitMessagingTemplate can be injected in a similar manner. If a MessageConverter bean is defined, it is associated
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automatically to the auto-configured AmqpTemplate .

If necessary, any org.springframework.amqp.core.Queue that is defined as a bean is automatically used to declare a corresponding queue on
the RabbitMQ instance.
To retry operations, you can enable retries on the AmqpTemplate (for example, in the event that the broker connection is lost):
spring.rabbitmq.template.retry.enabled=true
spring.rabbitmq.template.retry.initial-interval=2s

Retries are disabled by default. You can also customize the RetryTemplate programmatically by declaring a RabbitRetryTemplateCustomizer
bean.

33.2.3 Receiving a Message
When the Rabbit infrastructure is present, any bean can be annotated with @RabbitListener to create a listener endpoint. If no
RabbitListenerContainerFactory has been defined, a default SimpleRabbitListenerContainerFactory is automatically configured and
you can switch to a direct container using the spring.rabbitmq.listener.type property. If a MessageConverter or a MessageRecoverer
bean is defined, it is automatically associated with the default factory.
The following sample component creates a listener endpoint on the someQueue queue:
@Component
public class MyBean {
@RabbitListener(queues = "someQueue")
public void processMessage(String content) {
// ...
}
}

See the Javadoc of @EnableRabbit for more details.

If you need to create more RabbitListenerContainerFactory instances or if you want to override the default, Spring Boot provides a
SimpleRabbitListenerContainerFactoryConfigurer and a DirectRabbitListenerContainerFactoryConfigurer that you can use to
initialize a SimpleRabbitListenerContainerFactory and a DirectRabbitListenerContainerFactory with the same settings as the factories
used by the auto-configuration.

It does not matter which container type you chose. Those two beans are exposed by the auto-configuration.

For instance, the following configuration class exposes another factory that uses a specific MessageConverter :
@Configuration
static class RabbitConfiguration {
@Bean
public SimpleRabbitListenerContainerFactory myFactory(
SimpleRabbitListenerContainerFactoryConfigurer configurer) {
SimpleRabbitListenerContainerFactory factory =
new SimpleRabbitListenerContainerFactory();
configurer.configure(factory, connectionFactory);
factory.setMessageConverter(myMessageConverter());
return factory;
}
}

Then you can use the factory in any @RabbitListener -annotated method, as follows:

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@Component
public class MyBean {
@RabbitListener(queues = "someQueue", containerFactory="myFactory")
public void processMessage(String content) {
// ...
}
}

You can enable retries to handle situations where your listener throws an exception. By default, RejectAndDontRequeueRecoverer is used, but
you can define a MessageRecoverer of your own. When retries are exhausted, the message is rejected and either dropped or routed to a deadletter exchange if the broker is configured to do so. By default, retries are disabled. You can also customize the RetryTemplate programmatically
by declaring a RabbitRetryTemplateCustomizer bean.

Important
By default, if retries are disabled and the listener throws an exception, the delivery is retried indefinitely. You can modify this behavior
in two ways: Set the defaultRequeueRejected property to false so that zero re-deliveries are attempted or throw an
AmqpRejectAndDontRequeueException to signal the message should be rejected. The latter is the mechanism used when retries
are enabled and the maximum number of delivery attempts is reached.

33.3 Apache Kafka Support
Apache Kafka is supported by providing auto-configuration of the spring-kafka project.
Kafka configuration is controlled by external configuration properties in spring.kafka.* . For example, you might declare the following section in
application.properties :
spring.kafka.bootstrap-servers=localhost:9092
spring.kafka.consumer.group-id=myGroup

To create a topic on startup, add a bean of type NewTopic . If the topic already exists, the bean is ignored.

See KafkaProperties for more supported options.

33.3.1 Sending a Message
Spring’s KafkaTemplate is auto-configured, and you can autowire it directly in your own beans, as shown in the following example:
@Component
public class MyBean {
private final KafkaTemplate kafkaTemplate;
@Autowired
public MyBean(KafkaTemplate kafkaTemplate) {
this.kafkaTemplate = kafkaTemplate;
}
// ...
}

If the property spring.kafka.producer.transaction-id-prefix is defined, a KafkaTransactionManager is automatically
configured. Also, if a RecordMessageConverter bean is defined, it is automatically associated to the auto-configured
KafkaTemplate .

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33.3.2 Receiving a Message
When the Apache Kafka infrastructure is present, any bean can be annotated with @KafkaListener to create a listener endpoint. If no
KafkaListenerContainerFactory has been defined, a default one is automatically configured with keys defined in spring.kafka.listener.* .
The following component creates a listener endpoint on the someTopic topic:
@Component
public class MyBean {
@KafkaListener(topics = "someTopic")
public void processMessage(String content) {
// ...
}
}

If a KafkaTransactionManager bean is defined, it is automatically associated to the container factory. Similarly, if a RecordMessageConverter ,
ErrorHandler or AfterRollbackProcessor bean is defined, it is automatically associated to the default factory.

A custom ChainedKafkaTransactionManager must be marked @Primary as it usually references the auto-configured
KafkaTransactionManager bean.

33.3.3 Kafka Streams
Spring for Apache Kafka provides a factory bean to create a StreamsBuilder object and manage the lifecycle of its streams. Spring Boot autoconfigures the required KafkaStreamsConfiguration bean as long as kafka-streams is on the classpath and Kafka Streams is enabled via the
@EnableKafkaStreams annotation.
Enabling Kafka Streams means that the application id and bootstrap servers must be set. The former can be configured using
spring.kafka.streams.application-id , defaulting to spring.application.name if not set. The latter can be set globally or specifically
overridden just for streams.
Several additional properties are available using dedicated properties; other arbitrary Kafka properties can be set using the
spring.kafka.streams.properties namespace. See also Section 33.3.4, “Additional Kafka Properties” for more information.
To use the factory bean, simply wire StreamsBuilder into your @Bean as shown in the following example:
@Configuration
@EnableKafkaStreams
static class KafkaStreamsExampleConfiguration {
@Bean
public KStream kStream(StreamsBuilder streamsBuilder) {
KStream stream = streamsBuilder.stream("ks1In");
stream.map((k, v) -> new KeyValue<>(k, v.toUpperCase())).to("ks1Out",
Produced.with(Serdes.Integer(), new JsonSerde<>()));
return stream;
}

}

By default, the streams managed by the StreamBuilder object it creates are started automatically. You can customize this behaviour using the
spring.kafka.streams.auto-startup property.

33.3.4 Additional Kafka Properties
The properties supported by auto configuration are shown in Appendix A, Common application properties. Note that, for the most part, these
properties (hyphenated or camelCase) map directly to the Apache Kafka dotted properties. Refer to the Apache Kafka documentation for details.
The first few of these properties apply to all components (producers, consumers, admins, and streams) but can be specified at the component level
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configuration supports all HIGH importance properties, some selected MEDIUM and LOW properties, and any properties that do not have a default
value.
Only a subset of the properties supported by Kafka are available directly through the KafkaProperties class. If you wish to configure the producer
or consumer with additional properties that are not directly supported, use the following properties:
spring.kafka.properties.prop.one=first
spring.kafka.admin.properties.prop.two=second
spring.kafka.consumer.properties.prop.three=third
spring.kafka.producer.properties.prop.four=fourth
spring.kafka.streams.properties.prop.five=fifth

This sets the common prop.one Kafka property to first (applies to producers, consumers and admins), the prop.two admin property to
second , the prop.three consumer property to third , the prop.four producer property to fourth and the prop.five streams property to
fifth .
You can also configure the Spring Kafka JsonDeserializer as follows:
spring.kafka.consumer.value-deserializer=org.springframework.kafka.support.serializer.JsonDeserializer
spring.kafka.consumer.properties.spring.json.value.default.type=com.example.Invoice
spring.kafka.consumer.properties.spring.json.trusted.packages=com.example,org.acme

Similarly, you can disable the JsonSerializer default behavior of sending type information in headers:
spring.kafka.producer.value-serializer=org.springframework.kafka.support.serializer.JsonSerializer
spring.kafka.producer.properties.spring.json.add.type.headers=false

Important
Properties set in this way override any configuration item that Spring Boot explicitly supports.

34. Calling REST Services with RestTemplate
If you need to call remote REST services from your application, you can use the Spring Framework’s RestTemplate class. Since RestTemplate
instances often need to be customized before being used, Spring Boot does not provide any single auto-configured RestTemplate bean. It does,
however, auto-configure a RestTemplateBuilder , which can be used to create RestTemplate instances when needed. The auto-configured
RestTemplateBuilder ensures that sensible HttpMessageConverters are applied to RestTemplate instances.
The following code shows a typical example:
@Service
public class MyService {
private final RestTemplate restTemplate;
public MyService(RestTemplateBuilder restTemplateBuilder) {
this.restTemplate = restTemplateBuilder.build();
}
public Details someRestCall(String name) {
return this.restTemplate.getForObject("/{name}/details", Details.class, name);
}
}

RestTemplateBuilder includes a number of useful methods that can be used to quickly configure a RestTemplate . For example,
to add BASIC auth support, you can use builder.basicAuthentication("user", "password").build() .

34.1 RestTemplate Customization
There are three main approaches to RestTemplate customization, depending on how broadly you want the customizations to apply.
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To make the scope of any customizations as narrow as possible, inject the auto-configured RestTemplateBuilder and then call its methods as
required. Each method call returns a new RestTemplateBuilder instance, so the customizations only affect this use of the builder.
To make an application-wide, additive customization, use a RestTemplateCustomizer bean. All such beans are automatically registered with the
auto-configured RestTemplateBuilder and are applied to any templates that are built with it.
The following example shows a customizer that configures the use of a proxy for all hosts except 192.168.0.5 :
static class ProxyCustomizer implements RestTemplateCustomizer {
@Override
public void customize(RestTemplate restTemplate) {
HttpHost proxy = new HttpHost("proxy.example.com");
HttpClient httpClient = HttpClientBuilder.create()
.setRoutePlanner(new DefaultProxyRoutePlanner(proxy) {
@Override
public HttpHost determineProxy(HttpHost target,
HttpRequest request, HttpContext context)
throws HttpException {
if (target.getHostName().equals("192.168.0.5")) {
return null;
}
return super.determineProxy(target, request, context);
}
}).build();
restTemplate.setRequestFactory(
new HttpComponentsClientHttpRequestFactory(httpClient));
}
}

Finally, the most extreme (and rarely used) option is to create your own RestTemplateBuilder bean. Doing so switches off the auto-configuration
of a RestTemplateBuilder and prevents any RestTemplateCustomizer beans from being used.

35. Calling REST Services with WebClient
If you have Spring WebFlux on your classpath, you can also choose to use WebClient to call remote REST services. Compared to
RestTemplate , this client has a more functional feel and is fully reactive. You can learn more about the WebClient in the dedicated section in the
Spring Framework docs.
Spring Boot creates and pre-configures a WebClient.Builder for you; it is strongly advised to inject it in your components and use it to create
WebClient instances. Spring Boot is configuring that builder to share HTTP resources, reflect codecs setup in the same fashion as the server ones
(see WebFlux HTTP codecs auto-configuration), and more.
The following code shows a typical example:
@Service
public class MyService {
private final WebClient webClient;
public MyService(WebClient.Builder webClientBuilder) {
this.webClient = webClientBuilder.baseUrl("http://example.org").build();
}
public Mono
 someRestCall(String name) {
return this.webClient.get().uri("/{name}/details", name)
.retrieve().bodyToMono(Details.class);
}
}

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35.1 WebClient Runtime
Spring Boot will auto-detect which ClientHttpConnector to use to drive WebClient , depending on the libraries available on the application
classpath. For now, Reactor Netty and Jetty RS client are supported.
The spring-boot-starter-webflux starter depends on io.projectreactor.netty:reactor-netty by default, which brings both server and
client implementations. If you choose to use Jetty as a reactive server instead, you should add a dependency on the Jetty Reactive HTTP client
library, org.eclipse.jetty:jetty-reactive-httpclient . Using the same technology for server and client has it advantages, as it will
automatically share HTTP resources between client and server.
Developers can override the resource configuration for Jetty and Reactor Netty by providing a custom ReactorResourceFactory or
JettyResourceFactory bean - this will be applied to both clients and servers.
If you wish to override that choice for the client, you can define your own ClientHttpConnector bean and have full control over the client
configuration.
You can learn more about the WebClient configuration options in the Spring Framework reference documentation.

35.2 WebClient Customization
There are three main approaches to WebClient customization, depending on how broadly you want the customizations to apply.
To make the scope of any customizations as narrow as possible, inject the auto-configured WebClient.Builder and then call its methods as
required. WebClient.Builder instances are stateful: Any change on the builder is reflected in all clients subsequently created with it. If you want
to create several clients with the same builder, you can also consider cloning the builder with WebClient.Builder other = builder.clone(); .
To make an application-wide, additive customization to all WebClient.Builder instances, you can declare WebClientCustomizer beans and
change the WebClient.Builder locally at the point of injection.
Finally, you can fall back to the original API and use WebClient.create() . In that case, no auto-configuration or WebClientCustomizer is
applied.

36. Validation
The method validation feature supported by Bean Validation 1.1 is automatically enabled as long as a JSR-303 implementation (such as Hibernate
validator) is on the classpath. This lets bean methods be annotated with javax.validation constraints on their parameters and/or on their return
value. Target classes with such annotated methods need to be annotated with the @Validated annotation at the type level for their methods to be
searched for inline constraint annotations.
For instance, the following service triggers the validation of the first argument, making sure its size is between 8 and 10:
@Service
@Validated
public class MyBean {
public Archive findByCodeAndAuthor(@Size(min = 8, max = 10) String code,
Author author) {
...
}
}

37. Sending Email
The Spring Framework provides an easy abstraction for sending email by using the JavaMailSender interface, and Spring Boot provides autoconfiguration for it as well as a starter module.

See the reference documentation for a detailed explanation of how you can use JavaMailSender .

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If spring.mail.host and the relevant libraries (as defined by spring-boot-starter-mail ) are available, a default JavaMailSender is
created if none exists. The sender can be further customized by configuration items from the spring.mail namespace. See MailProperties for
more details.
In particular, certain default timeout values are infinite, and you may want to change that to avoid having a thread blocked by an unresponsive mail
server, as shown in the following example:
spring.mail.properties.mail.smtp.connectiontimeout=5000
spring.mail.properties.mail.smtp.timeout=3000
spring.mail.properties.mail.smtp.writetimeout=5000

It is also possible to configure a JavaMailSender with an existing Session from JNDI:
spring.mail.jndi-name=mail/Session

When a jndi-name is set, it takes precedence over all other Session-related settings.

38. Distributed Transactions with JTA
Spring Boot supports distributed JTA transactions across multiple XA resources by using either an Atomikos or Bitronix embedded transaction
manager. JTA transactions are also supported when deploying to a suitable Java EE Application Server.
When a JTA environment is detected, Spring’s JtaTransactionManager is used to manage transactions. Auto-configured JMS, DataSource, and
JPA beans are upgraded to support XA transactions. You can use standard Spring idioms, such as @Transactional , to participate in a distributed
transaction. If you are within a JTA environment and still want to use local transactions, you can set the spring.jta.enabled property to false
to disable the JTA auto-configuration.

38.1 Using an Atomikos Transaction Manager
Atomikos is a popular open source transaction manager which can be embedded into your Spring Boot application. You can use the
spring-boot-starter-jta-atomikos Starter to pull in the appropriate Atomikos libraries. Spring Boot auto-configures Atomikos and ensures that
appropriate depends-on settings are applied to your Spring beans for correct startup and shutdown ordering.
By default, Atomikos transaction logs are written to a transaction-logs directory in your application’s home directory (the directory in which your
application jar file resides). You can customize the location of this directory by setting a spring.jta.log-dir property in your
application.properties file. Properties starting with spring.jta.atomikos.properties can also be used to customize the Atomikos
UserTransactionServiceImp . See the AtomikosProperties Javadoc for complete details.

To ensure that multiple transaction managers can safely coordinate the same resource managers, each Atomikos instance must be
configured with a unique ID. By default, this ID is the IP address of the machine on which Atomikos is running. To ensure uniqueness
in production, you should configure the spring.jta.transaction-manager-id property with a different value for each instance of
your application.

38.2 Using a Bitronix Transaction Manager
Bitronix is a popular open-source JTA transaction manager implementation. You can use the spring-boot-starter-jta-bitronix starter to add
the appropriate Bitronix dependencies to your project. As with Atomikos, Spring Boot automatically configures Bitronix and post-processes your
beans to ensure that startup and shutdown ordering is correct.
By default, Bitronix transaction log files ( part1.btm and part2.btm ) are written to a transaction-logs directory in your application home
directory. You can customize the location of this directory by setting the spring.jta.log-dir property. Properties starting with
spring.jta.bitronix.properties are also bound to the bitronix.tm.Configuration bean, allowing for complete customization. See the
Bitronix documentation for details.

To ensure that multiple transaction managers can safely coordinate the same resource managers, each Bitronix instance must be
configured with a unique ID. By default, this ID is the IP address of the machine on which Bitronix is running. To ensure uniqueness in
production, you should configure the spring.jta.transaction-manager-id property with a different value for each instance of
your application.
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38.3 Using a Java EE Managed Transaction Manager
If you package your Spring Boot application as a war or ear file and deploy it to a Java EE application server, you can use your application
server’s built-in transaction manager. Spring Boot tries to auto-configure a transaction manager by looking at common JNDI locations
( java:comp/UserTransaction , java:comp/TransactionManager , and so on). If you use a transaction service provided by your application
server, you generally also want to ensure that all resources are managed by the server and exposed over JNDI. Spring Boot tries to auto-configure
JMS by looking for a ConnectionFactory at the JNDI path ( java:/JmsXA or java:/XAConnectionFactory ), and you can use the
spring.datasource.jndi-name property to configure your DataSource .

38.4 Mixing XA and Non-XA JMS Connections
When using JTA, the primary JMS ConnectionFactory bean is XA-aware and participates in distributed transactions. In some situations, you
might want to process certain JMS messages by using a non-XA ConnectionFactory . For example, your JMS processing logic might take longer
than the XA timeout.
If you want to use a non-XA ConnectionFactory , you can inject the nonXaJmsConnectionFactory bean rather than the @Primary
jmsConnectionFactory bean. For consistency, the jmsConnectionFactory bean is also provided by using the bean alias
xaJmsConnectionFactory .
The following example shows how to inject ConnectionFactory instances:
// Inject the primary (XA aware) ConnectionFactory
@Autowired
private ConnectionFactory defaultConnectionFactory;
// Inject the XA aware ConnectionFactory (uses the alias and injects the same as above)
@Autowired
@Qualifier("xaJmsConnectionFactory")
private ConnectionFactory xaConnectionFactory;
// Inject the non-XA aware ConnectionFactory
@Autowired
@Qualifier("nonXaJmsConnectionFactory")
private ConnectionFactory nonXaConnectionFactory;

38.5 Supporting an Alternative Embedded Transaction Manager
The XAConnectionFactoryWrapper and XADataSourceWrapper interfaces can be used to support alternative embedded transaction managers.
The interfaces are responsible for wrapping XAConnectionFactory and XADataSource beans and exposing them as regular
ConnectionFactory and DataSource beans, which transparently enroll in the distributed transaction. DataSource and JMS auto-configuration
use JTA variants, provided you have a JtaTransactionManager bean and appropriate XA wrapper beans registered within your
ApplicationContext .
The BitronixXAConnectionFactoryWrapper and BitronixXADataSourceWrapper provide good examples of how to write XA wrappers.

39. Hazelcast
If Hazelcast is on the classpath and a suitable configuration is found, Spring Boot auto-configures a HazelcastInstance that you can inject in your
application.
If you define a com.hazelcast.config.Config bean, Spring Boot uses that. If your configuration defines an instance name, Spring Boot tries to
locate an existing instance rather than creating a new one.
You could also specify the hazelcast.xml configuration file to use through configuration, as shown in the following example:
spring.hazelcast.config=classpath:config/my-hazelcast.xml

Otherwise, Spring Boot tries to find the Hazelcast configuration from the default locations: hazelcast.xml in the working directory or at the root of
the classpath. We also check if the hazelcast.config system property is set. See the Hazelcast documentation for more details.
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If hazelcast-client is present on the classpath, Spring Boot first attempts to create a client by checking the following configuration options:
The presence of a com.hazelcast.client.config.ClientConfig bean.
A configuration file defined by the spring.hazelcast.config property.
The presence of the hazelcast.client.config system property.
A hazelcast-client.xml in the working directory or at the root of the classpath.

Spring Boot also has explicit caching support for Hazelcast. If caching is enabled, the HazelcastInstance is automatically wrapped
in a CacheManager implementation.

40. Quartz Scheduler
Spring Boot offers several conveniences for working with the Quartz scheduler, including the spring-boot-starter-quartz “Starter”. If Quartz is
available, a Scheduler is auto-configured (through the SchedulerFactoryBean abstraction).
Beans of the following types are automatically picked up and associated with the Scheduler :
JobDetail : defines a particular Job. JobDetail instances can be built with the JobBuilder API.
Calendar .
Trigger : defines when a particular job is triggered.
By default, an in-memory JobStore is used. However, it is possible to configure a JDBC-based store if a DataSource bean is available in your
application and if the spring.quartz.job-store-type property is configured accordingly, as shown in the following example:
spring.quartz.job-store-type=jdbc

When the JDBC store is used, the schema can be initialized on startup, as shown in the following example:
spring.quartz.jdbc.initialize-schema=always

By default, the database is detected and initialized by using the standard scripts provided with the Quartz library. These scripts drop
existing tables, deleting all triggers on every restart. It is also possible to provide a custom script by setting the
spring.quartz.jdbc.schema property.

To have Quartz use a DataSource other than the application’s main DataSource , declare a DataSource bean, annotating its @Bean method
with @QuartzDataSource . Doing so ensures that the Quartz-specific DataSource is used by both the SchedulerFactoryBean and for schema
initialization.
By default, jobs created by configuration will not overwrite already registered jobs that have been read from a persistent job store. To enable
overwriting existing job definitions set the spring.quartz.overwrite-existing-jobs property.
Quartz Scheduler configuration can be customized using spring.quartz properties and SchedulerFactoryBeanCustomizer beans, which allow
programmatic SchedulerFactoryBean customization. Advanced Quartz configuration properties can be customized using
spring.quartz.properties.* .

In particular, an Executor bean is not associated with the scheduler as Quartz offers a way to configure the scheduler via
spring.quartz.properties . If you need to customize the task executor, consider implementing
SchedulerFactoryBeanCustomizer .

Jobs can define setters to inject data map properties. Regular beans can also be injected in a similar manner, as shown in the following example:
public class SampleJob extends QuartzJobBean {
private MyService myService;
private String name;
// Inject "MyService" bean
public void setMyService(MyService myService) { ... }

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// Inject the "name" job data property
public void setName(String name) { ... }
@Override
protected void executeInternal(JobExecutionContext context)
throws JobExecutionException {
...
}

}

41. Task Execution and Scheduling
In the absence of a TaskExecutor bean in the context, Spring Boot auto-configures a ThreadPoolTaskExecutor with sensible defaults that can
be automatically associated to asynchronous task execution ( @EnableAsync ) and Spring MVC asynchronous request processing.
The thread pool uses 8 core threads that can grow and shrink according to the load. Those default settings can be fine-tuned using the
spring.task.execution namespace as shown in the following example:
spring.task.execution.pool.max-threads=16
spring.task.execution.pool.queue-capacity=100
spring.task.execution.pool.keep-alive=10s

This changes the thread pool to use a bounded queue so that when the queue is full (100 tasks), the thread pool increases to maximum 16 threads.
Shrinking of the pool is more aggressive as threads are reclaimed when they are idle for 10 seconds (rather than 60 seconds by default).
A ThreadPoolTaskScheduler can also be auto-configured if need to be associated to scheduled task execution ( @EnableScheduling ). The
thread pool uses one thread by default and those settings can be fine-tuned using the spring.task.scheduling namespace.
Both a TaskExecutorBuilder bean and a TaskSchedulerBuilder bean are made available in the context if a custom executor or scheduler
needs to be created.

42. Spring Integration
Spring Boot offers several conveniences for working with Spring Integration, including the spring-boot-starter-integration “Starter”. Spring
Integration provides abstractions over messaging and also other transports such as HTTP, TCP, and others. If Spring Integration is available on your
classpath, it is initialized through the @EnableIntegration annotation.
Spring Boot also configures some features that are triggered by the presence of additional Spring Integration modules. If
spring-integration-jmx is also on the classpath, message processing statistics are published over JMX . If spring-integration-jdbc is
available, the default database schema can be created on startup, as shown in the following line:
spring.integration.jdbc.initialize-schema=always

See the IntegrationAutoConfiguration and IntegrationProperties classes for more details.
By default, if a Micrometer meterRegistry bean is present, Spring Integration metrics will be managed by Micrometer. If you wish to use legacy
Spring Integration metrics, add a DefaultMetricsFactory bean to the application context.

43. Spring Session
Spring Boot provides Spring Session auto-configuration for a wide range of data stores. When building a Servlet web application, the following
stores can be auto-configured:
JDBC
Redis
Hazelcast
MongoDB
When building a reactive web application, the following stores can be auto-configured:

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Redis
MongoDB
If a single Spring Session module is present on the classpath, Spring Boot uses that store implementation automatically. If you have more than one
implementation, you must choose the StoreType that you wish to use to store the sessions. For instance, to use JDBC as the back-end store, you
can configure your application as follows:
spring.session.store-type=jdbc

You can disable Spring Session by setting the store-type to none .

Each store has specific additional settings. For instance, it is possible to customize the name of the table for the JDBC store, as shown in the
following example:
spring.session.jdbc.table-name=SESSIONS

For setting the timeout of the session you can use the spring.session.timeout property. If that property is not set, the auto-configuration falls
back to the value of server.servlet.session.timeout .

44. Monitoring and Management over JMX
Java Management Extensions (JMX) provide a standard mechanism to monitor and manage applications. By default, Spring Boot creates an
MBeanServer bean with an ID of mbeanServer and exposes any of your beans that are annotated with Spring JMX annotations
( @ManagedResource , @ManagedAttribute , or @ManagedOperation ).
See the JmxAutoConfiguration class for more details.

45. Testing
Spring Boot provides a number of utilities and annotations to help when testing your application. Test support is provided by two modules:
spring-boot-test contains core items, and spring-boot-test-autoconfigure supports auto-configuration for tests.
Most developers use the spring-boot-starter-test “Starter”, which imports both Spring Boot test modules as well as JUnit, AssertJ, Hamcrest,
and a number of other useful libraries.

45.1 Test Scope Dependencies
The spring-boot-starter-test “Starter” (in the test scope ) contains the following provided libraries:
JUnit: The de-facto standard for unit testing Java applications.
Spring Test & Spring Boot Test: Utilities and integration test support for Spring Boot applications.
AssertJ: A fluent assertion library.
Hamcrest: A library of matcher objects (also known as constraints or predicates).
Mockito: A Java mocking framework.
JSONassert: An assertion library for JSON.
JsonPath: XPath for JSON.
We generally find these common libraries to be useful when writing tests. If these libraries do not suit your needs, you can add additional test
dependencies of your own.

45.2 Testing Spring Applications
One of the major advantages of dependency injection is that it should make your code easier to unit test. You can instantiate objects by using the
new operator without even involving Spring. You can also use mock objects instead of real dependencies.
Often, you need to move beyond unit testing and start integration testing (with a Spring ApplicationContext ). It is useful to be able to perform
integration testing without requiring deployment of your application or needing to connect to other infrastructure.

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The Spring Framework includes a dedicated test module for such integration testing. You can declare a dependency directly to
org.springframework:spring-test or use the spring-boot-starter-test “Starter” to pull it in transitively.
If you have not used the spring-test module before, you should start by reading the relevant section of the Spring Framework reference
documentation.

45.3 Testing Spring Boot Applications
A Spring Boot application is a Spring ApplicationContext , so nothing very special has to be done to test it beyond what you would normally do
with a vanilla Spring context.

External properties, logging, and other features of Spring Boot are installed in the context by default only if you use
SpringApplication to create it.

Spring Boot provides a @SpringBootTest annotation, which can be used as an alternative to the standard spring-test
@ContextConfiguration annotation when you need Spring Boot features. The annotation works by creating the ApplicationContext used in
your tests through SpringApplication . In addition to @SpringBootTest a number of other annotations are also provided for testing more
specific slices of an application.

If you are using JUnit 4, don’t forget to also add @RunWith(SpringRunner.class) to your test, otherwise the annotations will be
ignored. If you are using JUnit 5, there’s no need to add the equivalent @ExtendWith(SpringExtension) as @SpringBootTest
and the other @…Test annotations are already annotated with it.

By default, @SpringBootTest will not start a server. You can use the webEnvironment attribute of @SpringBootTest to further refine how your
tests run:
MOCK (Default) : Loads a web ApplicationContext and provides a mock web environment. Embedded servers are not started when using
this annotation. If a web environment is not available on your classpath, this mode transparently falls back to creating a regular non-web
ApplicationContext . It can be used in conjunction with @AutoConfigureMockMvc or @AutoConfigureWebTestClient for mock-based
testing of your web application.
RANDOM_PORT : Loads a WebServerApplicationContext and provides a real web environment. Embedded servers are started and listen on a
random port.
DEFINED_PORT : Loads a WebServerApplicationContext and provides a real web environment. Embedded servers are started and listen on
a defined port (from your application.properties ) or on the default port of 8080 .
NONE : Loads an ApplicationContext by using SpringApplication but does not provide any web environment (mock or otherwise).

If your test is @Transactional , it rolls back the transaction at the end of each test method by default. However, as using this
arrangement with either RANDOM_PORT or DEFINED_PORT implicitly provides a real servlet environment, the HTTP client and server
run in separate threads and, thus, in separate transactions. Any transaction initiated on the server does not roll back in this case.

@SpringBootTest with webEnvironment = WebEnvironment.RANDOM_PORT will also start the management server on a separate
random port if your application uses a different port for the management server.

45.3.1 Detecting Web Application Type
If Spring MVC is available, a regular MVC-based application context is configured. If you have only Spring WebFlux, we’ll detect that and configure a
WebFlux-based application context instead.
If both are present, Spring MVC takes precedence. If you want to test a reactive web application in this scenario, you must set the
spring.main.web-application-type property:
@RunWith(SpringRunner.class)
@SpringBootTest(properties = "spring.main.web-application-type=reactive")
public class MyWebFluxTests { ... }

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45.3.2 Detecting Test Configuration
If you are familiar with the Spring Test Framework, you may be used to using @ContextConfiguration(classes=…) in order to specify which
Spring @Configuration to load. Alternatively, you might have often used nested @Configuration classes within your test.
When testing Spring Boot applications, this is often not required. Spring Boot’s @*Test annotations search for your primary configuration
automatically whenever you do not explicitly define one.
The search algorithm works up from the package that contains the test until it finds a class annotated with @SpringBootApplication or
@SpringBootConfiguration . As long as you structured your code in a sensible way, your main configuration is usually found.

If you use a test annotation to test a more specific slice of your application, you should avoid adding configuration settings that are
specific to a particular area on the main method’s application class.
The underlying component scan configuration of @SpringBootApplication defines exclude filters that are used to make sure slicing
works as expected. If you are using an explicit @ComponentScan directive on your @SpringBootApplication -annotated class, be
aware that those filters will be disabled. If you are using slicing, you should define them again.

If you want to customize the primary configuration, you can use a nested @TestConfiguration class. Unlike a nested @Configuration class,
which would be used instead of your application’s primary configuration, a nested @TestConfiguration class is used in addition to your
application’s primary configuration.

Spring’s test framework caches application contexts between tests. Therefore, as long as your tests share the same configuration (no
matter how it is discovered), the potentially time-consuming process of loading the context happens only once.

45.3.3 Excluding Test Configuration
If your application uses component scanning (for example, if you use @SpringBootApplication or @ComponentScan ), you may find top-level
configuration classes that you created only for specific tests accidentally get picked up everywhere.
As we have seen earlier, @TestConfiguration can be used on an inner class of a test to customize the primary configuration. When placed on a
top-level class, @TestConfiguration indicates that classes in src/test/java should not be picked up by scanning. You can then import that
class explicitly where it is required, as shown in the following example:
@RunWith(SpringRunner.class)
@SpringBootTest
@Import(MyTestsConfiguration.class)
public class MyTests {
@Test
public void exampleTest() {
...
}
}

If you directly use @ComponentScan (that is, not through @SpringBootApplication ) you need to register the TypeExcludeFilter
with it. See the Javadoc for details.

45.3.4 Testing with a mock environment
By default, @SpringBootTest does not start the server. If you have web endpoints that you want to test against this mock environment, you can
additionally configure MockMvc as shown in the following example:

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;

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import
import
import
import

Spring Boot Reference Guide
org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
org.springframework.boot.test.context.SpringBootTest;
org.springframework.test.context.junit4.SpringRunner;
org.springframework.test.web.servlet.MockMvc;

import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
@RunWith(SpringRunner.class)
@SpringBootTest
@AutoConfigureMockMvc
public class MockMvcExampleTests {
@Autowired
private MockMvc mvc;
@Test
public void exampleTest() throws Exception {
this.mvc.perform(get("/")).andExpect(status().isOk())
.andExpect(content().string("Hello World"));
}
}

If you want to focus only on the web layer and not start a complete ApplicationContext , consider using @WebMvcTest instead.

Alternatively, you can configure a WebTestClient as shown in the following example:
import org.junit.Test;
import org.junit.runner.RunWith;
import
import
import
import
import

org.springframework.beans.factory.annotation.Autowired;
org.springframework.boot.test.autoconfigure.web.reactive.AutoConfigureWebTestClient;
org.springframework.boot.test.context.SpringBootTest;
org.springframework.test.context.junit4.SpringRunner;
org.springframework.test.web.reactive.server.WebTestClient;

@RunWith(SpringRunner.class)
@SpringBootTest
@AutoConfigureWebTestClient
public class MockWebTestClientExampleTests {
@Autowired
private WebTestClient webClient;
@Test
public void exampleTest() {
this.webClient.get().uri("/").exchange().expectStatus().isOk()
.expectBody(String.class).isEqualTo("Hello World");
}
}

45.3.5 Testing with a running server
If you need to start a full running server, we recommend that you use random ports. If you use
@SpringBootTest(webEnvironment=WebEnvironment.RANDOM_PORT) , an available port is picked at random each time your test runs.
The @LocalServerPort annotation can be used to inject the actual port used into your test. For convenience, tests that need to make REST calls
to the started server can additionally @Autowire a WebTestClient , which resolves relative links to the running server and comes with a dedicated
API for verifying responses, as shown in the following example:
import org.junit.Test;
import org.junit.runner.RunWith;

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import
import
import
import
import

Spring Boot Reference Guide
org.springframework.beans.factory.annotation.Autowired;
org.springframework.boot.test.context.SpringBootTest;
org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
org.springframework.test.context.junit4.SpringRunner;
org.springframework.test.web.reactive.server.WebTestClient;

@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
public class RandomPortWebTestClientExampleTests {
@Autowired
private WebTestClient webClient;
@Test
public void exampleTest() {
this.webClient.get().uri("/").exchange().expectStatus().isOk()
.expectBody(String.class).isEqualTo("Hello World");
}
}

This setup requires spring-webflux on the classpath. If you can’t or won’t add webflux, Spring Boot also provides a TestRestTemplate facility:
import org.junit.Test;
import org.junit.runner.RunWith;
import
import
import
import
import

org.springframework.beans.factory.annotation.Autowired;
org.springframework.boot.test.context.SpringBootTest;
org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
org.springframework.boot.test.web.client.TestRestTemplate;
org.springframework.test.context.junit4.SpringRunner;

import static org.assertj.core.api.Assertions.assertThat;

@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
public class RandomPortTestRestTemplateExampleTests {
@Autowired
private TestRestTemplate restTemplate;
@Test
public void exampleTest() {
String body = this.restTemplate.getForObject("/", String.class);
assertThat(body).isEqualTo("Hello World");
}
}

45.3.6 Using JMX
As the test context framework caches context, JMX is disabled by default to prevent identical components to register on the same domain. If such
test needs access to an MBeanServer , consider marking it dirty as well:
@RunWith(SpringRunner.class)
@SpringBootTest(properties = "spring.jmx.enabled=true")
@DirtiesContext
public class SampleJmxTests {
@Autowired
private MBeanServer mBeanServer;
@Test
public void exampleTest() {
// ...
}

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}

45.3.7 Mocking and Spying Beans
When running tests, it is sometimes necessary to mock certain components within your application context. For example, you may have a facade
over some remote service that is unavailable during development. Mocking can also be useful when you want to simulate failures that might be hard
to trigger in a real environment.
Spring Boot includes a @MockBean annotation that can be used to define a Mockito mock for a bean inside your ApplicationContext . You can
use the annotation to add new beans or replace a single existing bean definition. The annotation can be used directly on test classes, on fields
within your test, or on @Configuration classes and fields. When used on a field, the instance of the created mock is also injected. Mock beans are
automatically reset after each test method.

If your test uses one of Spring Boot’s test annotations (such as @SpringBootTest ), this feature is automatically enabled. To use this
feature with a different arrangement, a listener must be explicitly added, as shown in the following example:
@TestExecutionListeners(MockitoTestExecutionListener.class)

The following example replaces an existing RemoteService bean with a mock implementation:
import
import
import
import
import
import

org.junit.*;
org.junit.runner.*;
org.springframework.beans.factory.annotation.*;
org.springframework.boot.test.context.*;
org.springframework.boot.test.mock.mockito.*;
org.springframework.test.context.junit4.*;

import static org.assertj.core.api.Assertions.*;
import static org.mockito.BDDMockito.*;
@RunWith(SpringRunner.class)
@SpringBootTest
public class MyTests {
@MockBean
private RemoteService remoteService;
@Autowired
private Reverser reverser;
@Test
public void exampleTest() {
// RemoteService has been injected into the reverser bean
given(this.remoteService.someCall()).willReturn("mock");
String reverse = reverser.reverseSomeCall();
assertThat(reverse).isEqualTo("kcom");
}
}

Additionally, you can use @SpyBean to wrap any existing bean with a Mockito spy . See the Javadoc for full details.

While Spring’s test framework caches application contexts between tests and reuses a context for tests sharing the same
configuration, the use of @MockBean or @SpyBean influences the cache key, which will most likely increase the number of contexts.

If you are using @SpyBean to spy on a bean with @Cacheable methods that refer to parameters by name, your application must be
compiled with -parameters . This ensures that the parameter names are available to the caching infrastructure once the bean has
been spied upon.

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45.3.8 Auto-configured Tests
Spring Boot’s auto-configuration system works well for applications but can sometimes be a little too much for tests. It often helps to load only the
parts of the configuration that are required to test a “slice” of your application. For example, you might want to test that Spring MVC controllers are
mapping URLs correctly, and you do not want to involve database calls in those tests, or you might want to test JPA entities, and you are not
interested in the web layer when those tests run.
The spring-boot-test-autoconfigure module includes a number of annotations that can be used to automatically configure such “slices”. Each
of them works in a similar way, providing a @…Test annotation that loads the ApplicationContext and one or more @AutoConfigure…
annotations that can be used to customize auto-configuration settings.

Each slice restricts component scan to appropriate components and loads a very restricted set of auto-configuration classes. If you
need to exclude one of them, most @…Test annotations provide an excludeAutoConfiguration attribute. Alternatively, you can
use @ImportAutoConfiguration#exclude .

Including multiple “slices” by using several @…Test annotations in one test is not supported. If you need multiple “slices”, pick one of
the @…Test annotations and include the @AutoConfigure… annotations of the other “slices” by hand.

It is also possible to use the @AutoConfigure… annotations with the standard @SpringBootTest annotation. You can use this
combination if you are not interested in “slicing” your application but you want some of the auto-configured test beans.

45.3.9 Auto-configured JSON Tests
To test that object JSON serialization and deserialization is working as expected, you can use the @JsonTest annotation. @JsonTest autoconfigures the available supported JSON mapper, which can be one of the following libraries:
Jackson ObjectMapper , any @JsonComponent beans and any Jackson Module s
Gson
Jsonb

A list of the auto-configurations that are enabled by @JsonTest can be found in the appendix.

If you need to configure elements of the auto-configuration, you can use the @AutoConfigureJsonTesters annotation.
Spring Boot includes AssertJ-based helpers that work with the JSONAssert and JsonPath libraries to check that JSON appears as expected. The
JacksonTester , GsonTester , JsonbTester , and BasicJsonTester classes can be used for Jackson, Gson, Jsonb, and Strings respectively.
Any helper fields on the test class can be @Autowired when using @JsonTest . The following example shows a test class for Jackson:

import
import
import
import
import
import
import

org.junit.*;
org.junit.runner.*;
org.springframework.beans.factory.annotation.*;
org.springframework.boot.test.autoconfigure.json.*;
org.springframework.boot.test.context.*;
org.springframework.boot.test.json.*;
org.springframework.test.context.junit4.*;

import static org.assertj.core.api.Assertions.*;
@RunWith(SpringRunner.class)
@JsonTest
public class MyJsonTests {
@Autowired
private JacksonTester json;
@Test
public void testSerialize() throws Exception {

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VehicleDetails details = new VehicleDetails("Honda", "Civic");
// Assert against a `.json` file in the same package as the test
assertThat(this.json.write(details)).isEqualToJson("expected.json");
// Or use JSON path based assertions
assertThat(this.json.write(details)).hasJsonPathStringValue("@.make");
assertThat(this.json.write(details)).extractingJsonPathStringValue("@.make")
.isEqualTo("Honda");
}
@Test
public void testDeserialize() throws Exception {
String content = "{\"make\":\"Ford\",\"model\":\"Focus\"}";
assertThat(this.json.parse(content))
.isEqualTo(new VehicleDetails("Ford", "Focus"));
assertThat(this.json.parseObject(content).getMake()).isEqualTo("Ford");
}

}

JSON helper classes can also be used directly in standard unit tests. To do so, call the initFields method of the helper in your
@Before method if you do not use @JsonTest .

45.3.10 Auto-configured Spring MVC Tests
To test whether Spring MVC controllers are working as expected, use the @WebMvcTest annotation. @WebMvcTest auto-configures the Spring
MVC infrastructure and limits scanned beans to @Controller , @ControllerAdvice , @JsonComponent , Converter , GenericConverter ,
Filter , WebMvcConfigurer , and HandlerMethodArgumentResolver . Regular @Component beans are not scanned when using this
annotation.

A list of the auto-configuration settings that are enabled by @WebMvcTest can be found in the appendix.

If you need to register extra components, such as the Jackson Module , you can import additional configuration classes by using
@Import on your test.

Often, @WebMvcTest is limited to a single controller and is used in combination with @MockBean to provide mock implementations for required
collaborators.
@WebMvcTest also auto-configures MockMvc . Mock MVC offers a powerful way to quickly test MVC controllers without needing to start a full HTTP
server.

You can also auto-configure MockMvc in a non- @WebMvcTest (such as @SpringBootTest ) by annotating it with
@AutoConfigureMockMvc . The following example uses MockMvc :

import
import
import
import
import

org.junit.*;
org.junit.runner.*;
org.springframework.beans.factory.annotation.*;
org.springframework.boot.test.autoconfigure.web.servlet.*;
org.springframework.boot.test.mock.mockito.*;

import
import
import
import

static
static
static
static

org.assertj.core.api.Assertions.*;
org.mockito.BDDMockito.*;
org.springframework.test.web.servlet.request.MockMvcRequestBuilders.*;
org.springframework.test.web.servlet.result.MockMvcResultMatchers.*;

@RunWith(SpringRunner.class)
@WebMvcTest(UserVehicleController.class)
public class MyControllerTests {
@Autowired
private MockMvc mvc;

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@MockBean
private UserVehicleService userVehicleService;
@Test
public void testExample() throws Exception {
given(this.userVehicleService.getVehicleDetails("sboot"))
.willReturn(new VehicleDetails("Honda", "Civic"));
this.mvc.perform(get("/sboot/vehicle").accept(MediaType.TEXT_PLAIN))
.andExpect(status().isOk()).andExpect(content().string("Honda Civic"));
}

}

If you need to configure elements of the auto-configuration (for example, when servlet filters should be applied) you can use attributes
in the @AutoConfigureMockMvc annotation.

If you use HtmlUnit or Selenium, auto-configuration also provides an HTMLUnit WebClient bean and/or a WebDriver bean. The following
example uses HtmlUnit:
import
import
import
import
import
import

com.gargoylesoftware.htmlunit.*;
org.junit.*;
org.junit.runner.*;
org.springframework.beans.factory.annotation.*;
org.springframework.boot.test.autoconfigure.web.servlet.*;
org.springframework.boot.test.mock.mockito.*;

import static org.assertj.core.api.Assertions.*;
import static org.mockito.BDDMockito.*;
@RunWith(SpringRunner.class)
@WebMvcTest(UserVehicleController.class)
public class MyHtmlUnitTests {
@Autowired
private WebClient webClient;
@MockBean
private UserVehicleService userVehicleService;
@Test
public void testExample() throws Exception {
given(this.userVehicleService.getVehicleDetails("sboot"))
.willReturn(new VehicleDetails("Honda", "Civic"));
HtmlPage page = this.webClient.getPage("/sboot/vehicle.html");
assertThat(page.getBody().getTextContent()).isEqualTo("Honda Civic");
}
}

By default, Spring Boot puts WebDriver beans in a special “scope” to ensure that the driver exits after each test and that a new
instance is injected. If you do not want this behavior, you can add @Scope("singleton") to your WebDriver @Bean definition.

The webDriver scope created by Spring Boot will replace any user defined scope of the same name. If you define your own
webDriver scope you may find it stops working when you use @WebMvcTest .

If you have Spring Security on the classpath, @WebMvcTest will also scan WebSecurityConfigurer beans. Instead of disabling security
completely for such tests, you can use Spring Security’s test support. More details on how to use Spring Security’s MockMvc support can be found
in this Chapter 80, Testing With Spring Security how-to section.

Sometimes writing Spring MVC tests is not enough; Spring Boot can help you run full end-to-end tests with an actual server.
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45.3.11 Auto-configured Spring WebFlux Tests
To test that Spring WebFlux controllers are working as expected, you can use the @WebFluxTest annotation. @WebFluxTest auto-configures the
Spring WebFlux infrastructure and limits scanned beans to @Controller , @ControllerAdvice , @JsonComponent , Converter ,
GenericConverter , and WebFluxConfigurer . Regular @Component beans are not scanned when the @WebFluxTest annotation is used.

A list of the auto-configurations that are enabled by @WebFluxTest can be found in the appendix.

If you need to register extra components, such as Jackson Module , you can import additional configuration classes using @Import
on your test.

Often, @WebFluxTest is limited to a single controller and used in combination with the @MockBean annotation to provide mock implementations for
required collaborators.
@WebFluxTest also auto-configures WebTestClient , which offers a powerful way to quickly test WebFlux controllers without needing to start a full
HTTP server.

You can also auto-configure WebTestClient in a non- @WebFluxTest (such as @SpringBootTest ) by annotating it with
@AutoConfigureWebTestClient . The following example shows a class that uses both @WebFluxTest and a WebTestClient :

import org.junit.Test;
import org.junit.runner.RunWith;
import
import
import
import
import

org.springframework.beans.factory.annotation.Autowired;
org.springframework.boot.test.autoconfigure.web.reactive.WebFluxTest;
org.springframework.http.MediaType;
org.springframework.test.context.junit4.SpringRunner;
org.springframework.test.web.reactive.server.WebTestClient;

@RunWith(SpringRunner.class)
@WebFluxTest(UserVehicleController.class)
public class MyControllerTests {
@Autowired
private WebTestClient webClient;
@MockBean
private UserVehicleService userVehicleService;
@Test
public void testExample() throws Exception {
given(this.userVehicleService.getVehicleDetails("sboot"))
.willReturn(new VehicleDetails("Honda", "Civic"));
this.webClient.get().uri("/sboot/vehicle").accept(MediaType.TEXT_PLAIN)
.exchange()
.expectStatus().isOk()
.expectBody(String.class).isEqualTo("Honda Civic");
}
}

This setup is only supported by WebFlux applications as using WebTestClient in a mocked web application only works with
WebFlux at the moment.

@WebFluxTest cannot detect routes registered via the functional web framework. For testing RouterFunction beans in the context,
consider importing your RouterFunction yourself via @Import or using @SpringBootTest .
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Sometimes writing Spring WebFlux tests is not enough; Spring Boot can help you run full end-to-end tests with an actual server.

45.3.12 Auto-configured Data JPA Tests
You can use the @DataJpaTest annotation to test JPA applications. By default, it configures an in-memory embedded database, scans for
@Entity classes, and configures Spring Data JPA repositories. Regular @Component beans are not loaded into the ApplicationContext .

A list of the auto-configuration settings that are enabled by @DataJpaTest can be found in the appendix.

By default, data JPA tests are transactional and roll back at the end of each test. See the relevant section in the Spring Framework Reference
Documentation for more details. If that is not what you want, you can disable transaction management for a test or for the whole class as follows:
import
import
import
import
import
import

org.junit.Test;
org.junit.runner.RunWith;
org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
org.springframework.test.context.junit4.SpringRunner;
org.springframework.transaction.annotation.Propagation;
org.springframework.transaction.annotation.Transactional;

@RunWith(SpringRunner.class)
@DataJpaTest
@Transactional(propagation = Propagation.NOT_SUPPORTED)
public class ExampleNonTransactionalTests {
}

Data JPA tests may also inject a TestEntityManager bean, which provides an alternative to the standard JPA EntityManager that is specifically
designed for tests. If you want to use TestEntityManager outside of @DataJpaTest instances, you can also use the
@AutoConfigureTestEntityManager annotation. A JdbcTemplate is also available if you need that. The following example shows the
@DataJpaTest annotation in use:
import org.junit.*;
import org.junit.runner.*;
import org.springframework.boot.test.autoconfigure.orm.jpa.*;
import static org.assertj.core.api.Assertions.*;
@RunWith(SpringRunner.class)
@DataJpaTest
public class ExampleRepositoryTests {
@Autowired
private TestEntityManager entityManager;
@Autowired
private UserRepository repository;
@Test
public void testExample() throws Exception {
this.entityManager.persist(new User("sboot", "1234"));
User user = this.repository.findByUsername("sboot");
assertThat(user.getUsername()).isEqualTo("sboot");
assertThat(user.getVin()).isEqualTo("1234");
}
}

In-memory embedded databases generally work well for tests, since they are fast and do not require any installation. If, however, you prefer to run
tests against a real database you can use the @AutoConfigureTestDatabase annotation, as shown in the following example:
@RunWith(SpringRunner.class)
@DataJpaTest
@AutoConfigureTestDatabase(replace=Replace.NONE)

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public class ExampleRepositoryTests {
// ...
}

45.3.13 Auto-configured JDBC Tests
@JdbcTest is similar to @DataJpaTest but is for tests that only require a DataSource and do not use Spring Data JDBC. By default, it configures
an in-memory embedded database and a JdbcTemplate . Regular @Component beans are not loaded into the ApplicationContext .

A list of the auto-configurations that are enabled by @JdbcTest can be found in the appendix.

By default, JDBC tests are transactional and roll back at the end of each test. See the relevant section in the Spring Framework Reference
Documentation for more details. If that is not what you want, you can disable transaction management for a test or for the whole class, as follows:
import
import
import
import
import
import

org.junit.Test;
org.junit.runner.RunWith;
org.springframework.boot.test.autoconfigure.jdbc.JdbcTest;
org.springframework.test.context.junit4.SpringRunner;
org.springframework.transaction.annotation.Propagation;
org.springframework.transaction.annotation.Transactional;

@RunWith(SpringRunner.class)
@JdbcTest
@Transactional(propagation = Propagation.NOT_SUPPORTED)
public class ExampleNonTransactionalTests {
}

If you prefer your test to run against a real database, you can use the @AutoConfigureTestDatabase annotation in the same way as for
DataJpaTest . (See "Section 45.3.12, “Auto-configured Data JPA Tests”".)

45.3.14 Auto-configured Data JDBC Tests
@DataJdbcTest is similar to @JdbcTest but is for tests that use Spring Data JDBC repositories. By default, it configures an in-memory embedded
database, a JdbcTemplate , and Spring Data JDBC repositories. Regular @Component beans are not loaded into the ApplicationContext .

A list of the auto-configurations that are enabled by @DataJdbcTest can be found in the appendix.

By default, Data JDBC tests are transactional and roll back at the end of each test. See the relevant section in the Spring Framework Reference
Documentation for more details. If that is not what you want, you can disable transaction management for a test or for the whole test class as shown
in the JDBC example.
If you prefer your test to run against a real database, you can use the @AutoConfigureTestDatabase annotation in the same way as for
DataJpaTest . (See "Section 45.3.12, “Auto-configured Data JPA Tests”".)

45.3.15 Auto-configured jOOQ Tests
You can use @JooqTest in a similar fashion as @JdbcTest but for jOOQ-related tests. As jOOQ relies heavily on a Java-based schema that
corresponds with the database schema, the existing DataSource is used. If you want to replace it with an in-memory database, you can use
@AutoConfigureTestDatabase to override those settings. (For more about using jOOQ with Spring Boot, see "Section 30.6, “Using jOOQ”",
earlier in this chapter.) Regular @Component beans are not loaded into the ApplicationContext .

A list of the auto-configurations that are enabled by @JooqTest can be found in the appendix.

@JooqTest configures a DSLContext . Regular @Component beans are not loaded into the ApplicationContext . The following example shows
the @JooqTest annotation in use:
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import
import
import
import
import

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org.jooq.DSLContext;
org.junit.Test;
org.junit.runner.RunWith;
org.springframework.boot.test.autoconfigure.jooq.JooqTest;
org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@JooqTest
public class ExampleJooqTests {
@Autowired
private DSLContext dslContext;
}

JOOQ tests are transactional and roll back at the end of each test by default. If that is not what you want, you can disable transaction management
for a test or for the whole test class as shown in the JDBC example.

45.3.16 Auto-configured Data MongoDB Tests
You can use @DataMongoTest to test MongoDB applications. By default, it configures an in-memory embedded MongoDB (if available), configures
a MongoTemplate , scans for @Document classes, and configures Spring Data MongoDB repositories. Regular @Component beans are not loaded
into the ApplicationContext . (For more about using MongoDB with Spring Boot, see "Section 31.2, “MongoDB”", earlier in this chapter.)

A list of the auto-configuration settings that are enabled by @DataMongoTest can be found in the appendix.

The following class shows the @DataMongoTest annotation in use:
import
import
import
import
import

org.junit.runner.RunWith;
org.springframework.beans.factory.annotation.Autowired;
org.springframework.boot.test.autoconfigure.data.mongo.DataMongoTest;
org.springframework.data.mongodb.core.MongoTemplate;
org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@DataMongoTest
public class ExampleDataMongoTests {
@Autowired
private MongoTemplate mongoTemplate;
//
}

In-memory embedded MongoDB generally works well for tests, since it is fast and does not require any developer installation. If, however, you prefer
to run tests against a real MongoDB server, you should exclude the embedded MongoDB auto-configuration, as shown in the following example:
import org.junit.runner.RunWith;
import org.springframework.boot.autoconfigure.mongo.embedded.EmbeddedMongoAutoConfiguration;
import org.springframework.boot.test.autoconfigure.data.mongo.DataMongoTest;
import org.springframework.test.context.junit4.SpringRunner;
@RunWith(SpringRunner.class)
@DataMongoTest(excludeAutoConfiguration = EmbeddedMongoAutoConfiguration.class)
public class ExampleDataMongoNonEmbeddedTests {
}

45.3.17 Auto-configured Data Neo4j Tests
You can use @DataNeo4jTest to test Neo4j applications. By default, it uses an in-memory embedded Neo4j (if the embedded driver is available),
scans for @NodeEntity classes, and configures Spring Data Neo4j repositories. Regular @Component beans are not loaded into the
ApplicationContext . (For more about using Neo4J with Spring Boot, see "Section 31.3, “Neo4j”", earlier in this chapter.)

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A list of the auto-configuration settings that are enabled by @DataNeo4jTest can be found in the appendix.

The following example shows a typical setup for using Neo4J tests in Spring Boot:
import
import
import
import

org.junit.runner.RunWith;
org.springframework.beans.factory.annotation.Autowired;
org.springframework.boot.test.autoconfigure.data.neo4j.DataNeo4jTest;
org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@DataNeo4jTest
public class ExampleDataNeo4jTests {
@Autowired
private YourRepository repository;
//
}

By default, Data Neo4j tests are transactional and roll back at the end of each test. See the relevant section in the Spring Framework Reference
Documentation for more details. If that is not what you want, you can disable transaction management for a test or for the whole class, as follows:
import
import
import
import
import
import

org.junit.Test;
org.junit.runner.RunWith;
org.springframework.boot.test.autoconfigure.data.neo4j.DataNeo4jTest;
org.springframework.test.context.junit4.SpringRunner;
org.springframework.transaction.annotation.Propagation;
org.springframework.transaction.annotation.Transactional;

@RunWith(SpringRunner.class)
@DataNeo4jTest
@Transactional(propagation = Propagation.NOT_SUPPORTED)
public class ExampleNonTransactionalTests {
}

45.3.18 Auto-configured Data Redis Tests
You can use @DataRedisTest to test Redis applications. By default, it scans for @RedisHash classes and configures Spring Data Redis
repositories. Regular @Component beans are not loaded into the ApplicationContext . (For more about using Redis with Spring Boot, see
"Section 31.1, “Redis”", earlier in this chapter.)

A list of the auto-configuration settings that are enabled by @DataRedisTest can be found in the appendix.

The following example shows the @DataRedisTest annotation in use:
import
import
import
import

org.junit.runner.RunWith;
org.springframework.beans.factory.annotation.Autowired;
org.springframework.boot.test.autoconfigure.data.redis.DataRedisTest;
org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@DataRedisTest
public class ExampleDataRedisTests {
@Autowired
private YourRepository repository;
//
}

45.3.19 Auto-configured Data LDAP Tests
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You can use @DataLdapTest to test LDAP applications. By default, it configures an in-memory embedded LDAP (if available), configures an
LdapTemplate , scans for @Entry classes, and configures Spring Data LDAP repositories. Regular @Component beans are not loaded into the
ApplicationContext . (For more about using LDAP with Spring Boot, see "Section 31.9, “LDAP”", earlier in this chapter.)

A list of the auto-configuration settings that are enabled by @DataLdapTest can be found in the appendix.

The following example shows the @DataLdapTest annotation in use:
import
import
import
import
import

org.junit.runner.RunWith;
org.springframework.beans.factory.annotation.Autowired;
org.springframework.boot.test.autoconfigure.data.ldap.DataLdapTest;
org.springframework.ldap.core.LdapTemplate;
org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@DataLdapTest
public class ExampleDataLdapTests {
@Autowired
private LdapTemplate ldapTemplate;
//
}

In-memory embedded LDAP generally works well for tests, since it is fast and does not require any developer installation. If, however, you prefer to
run tests against a real LDAP server, you should exclude the embedded LDAP auto-configuration, as shown in the following example:
import
import
import
import

org.junit.runner.RunWith;
org.springframework.boot.autoconfigure.ldap.embedded.EmbeddedLdapAutoConfiguration;
org.springframework.boot.test.autoconfigure.data.ldap.DataLdapTest;
org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@DataLdapTest(excludeAutoConfiguration = EmbeddedLdapAutoConfiguration.class)
public class ExampleDataLdapNonEmbeddedTests {
}

45.3.20 Auto-configured REST Clients
You can use the @RestClientTest annotation to test REST clients. By default, it auto-configures Jackson, GSON, and Jsonb support, configures
a RestTemplateBuilder , and adds support for MockRestServiceServer . Regular @Component beans are not loaded into the
ApplicationContext .

A list of the auto-configuration settings that are enabled by @RestClientTest can be found in the appendix.

The specific beans that you want to test should be specified by using the value or components attribute of @RestClientTest , as shown in the
following example:
@RunWith(SpringRunner.class)
@RestClientTest(RemoteVehicleDetailsService.class)
public class ExampleRestClientTest {
@Autowired
private RemoteVehicleDetailsService service;
@Autowired
private MockRestServiceServer server;
@Test
public void getVehicleDetailsWhenResultIsSuccessShouldReturnDetails()
throws Exception {

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this.server.expect(requestTo("/greet/details"))
.andRespond(withSuccess("hello", MediaType.TEXT_PLAIN));
String greeting = this.service.callRestService();
assertThat(greeting).isEqualTo("hello");
}

}

45.3.21 Auto-configured Spring REST Docs Tests
You can use the @AutoConfigureRestDocs annotation to use Spring REST Docs in your tests with Mock MVC, REST Assured, or WebTestClient.
It removes the need for the JUnit rule in Spring REST Docs.
@AutoConfigureRestDocs can be used to override the default output directory ( target/generated-snippets if you are using Maven or
build/generated-snippets if you are using Gradle). It can also be used to configure the host, scheme, and port that appears in any documented
URIs.

Auto-configured Spring REST Docs Tests with Mock MVC
@AutoConfigureRestDocs customizes the MockMvc bean to use Spring REST Docs. You can inject it by using @Autowired and use it in your
tests as you normally would when using Mock MVC and Spring REST Docs, as shown in the following example:
import org.junit.Test;
import org.junit.runner.RunWith;
import
import
import
import
import

org.springframework.beans.factory.annotation.Autowired;
org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
org.springframework.http.MediaType;
org.springframework.test.context.junit4.SpringRunner;
org.springframework.test.web.servlet.MockMvc;

import static org.springframework.restdocs.mockmvc.MockMvcRestDocumentation.document;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*;
@RunWith(SpringRunner.class)
@WebMvcTest(UserController.class)
@AutoConfigureRestDocs
public class UserDocumentationTests {
@Autowired
private MockMvc mvc;
@Test
public void listUsers() throws Exception {
this.mvc.perform(get("/users").accept(MediaType.TEXT_PLAIN))
.andExpect(status().isOk())
.andDo(document("list-users"));
}
}

If you require more control over Spring REST Docs configuration than offered by the attributes of @AutoConfigureRestDocs , you can use a
RestDocsMockMvcConfigurationCustomizer bean, as shown in the following example:
@TestConfiguration
static class CustomizationConfiguration
implements RestDocsMockMvcConfigurationCustomizer {
@Override
public void customize(MockMvcRestDocumentationConfigurer configurer) {
configurer.snippets().withTemplateFormat(TemplateFormats.markdown());
}
}

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If you want to make use of Spring REST Docs support for a parameterized output directory, you can create a RestDocumentationResultHandler
bean. The auto-configuration calls alwaysDo with this result handler, thereby causing each MockMvc call to automatically generate the default
snippets. The following example shows a RestDocumentationResultHandler being defined:
@TestConfiguration
static class ResultHandlerConfiguration {
@Bean
public RestDocumentationResultHandler restDocumentation() {
return MockMvcRestDocumentation.document("{method-name}");
}
}

Auto-configured Spring REST Docs Tests with REST Assured
@AutoConfigureRestDocs makes a RequestSpecification bean, preconfigured to use Spring REST Docs, available to your tests. You can
inject it by using @Autowired and use it in your tests as you normally would when using REST Assured and Spring REST Docs, as shown in the
following example:
import io.restassured.specification.RequestSpecification;
import org.junit.Test;
import org.junit.runner.RunWith;
import
import
import
import
import
import

org.springframework.beans.factory.annotation.Autowired;
org.springframework.boot.test.autoconfigure.restdocs.AutoConfigureRestDocs;
org.springframework.boot.test.context.SpringBootTest;
org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
org.springframework.boot.web.server.LocalServerPort;
org.springframework.test.context.junit4.SpringRunner;

import static io.restassured.RestAssured.given;
import static org.hamcrest.CoreMatchers.is;
import static org.springframework.restdocs.restassured3.RestAssuredRestDocumentation.document;
@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
@AutoConfigureRestDocs
public class UserDocumentationTests {
@LocalServerPort
private int port;
@Autowired
private RequestSpecification documentationSpec;
@Test
public void listUsers() {
given(this.documentationSpec).filter(document("list-users")).when()
.port(this.port).get("/").then().assertThat().statusCode(is(200));
}
}

If you require more control over Spring REST Docs configuration than offered by the attributes of @AutoConfigureRestDocs , a
RestDocsRestAssuredConfigurationCustomizer bean can be used, as shown in the following example:
@TestConfiguration
public static class CustomizationConfiguration
implements RestDocsRestAssuredConfigurationCustomizer {
@Override
public void customize(RestAssuredRestDocumentationConfigurer configurer) {
configurer.snippets().withTemplateFormat(TemplateFormats.markdown());
}
}

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45.3.22 Additional Auto-configuration and Slicing
Each slice provides one or more @AutoConfigure… annotations that namely defines the auto-configurations that should be included as part of a
slice. Additional auto-configurations can be added by creating a custom @AutoConfigure… annotation or simply by adding
@ImportAutoConfiguration to the test as shown in the following example:
@RunWith(SpringRunner.class)
@JdbcTest
@ImportAutoConfiguration(IntegrationAutoConfiguration.class)
public class ExampleJdbcTests {
}

Make sure to not use the regular @Import annotation to import auto-configurations as they are handled in a specific way by Spring
Boot.

45.3.23 User Configuration and Slicing
If you structure your code in a sensible way, your @SpringBootApplication class is used by default as the configuration of your tests.
It then becomes important not to litter the application’s main class with configuration settings that are specific to a particular area of its functionality.
Assume that you are using Spring Batch and you rely on the auto-configuration for it. You could define your @SpringBootApplication as follows:
@SpringBootApplication
@EnableBatchProcessing
public class SampleApplication { ... }

Because this class is the source configuration for the test, any slice test actually tries to start Spring Batch, which is definitely not what you want to
do. A recommended approach is to move that area-specific configuration to a separate @Configuration class at the same level as your
application, as shown in the following example:
@Configuration
@EnableBatchProcessing
public class BatchConfiguration { ... }

Depending on the complexity of your application, you may either have a single @Configuration class for your customizations or one
class per domain area. The latter approach lets you enable it in one of your tests, if necessary, with the @Import annotation.

Another source of confusion is classpath scanning. Assume that, while you structured your code in a sensible way, you need to scan an additional
package. Your application may resemble the following code:
@SpringBootApplication
@ComponentScan({ "com.example.app", "org.acme.another" })
public class SampleApplication { ... }

Doing so effectively overrides the default component scan directive with the side effect of scanning those two packages regardless of the slice that
you chose. For instance, a @DataJpaTest seems to suddenly scan components and user configurations of your application. Again, moving the
custom directive to a separate class is a good way to fix this issue.

If this is not an option for you, you can create a @SpringBootConfiguration somewhere in the hierarchy of your test so that it is
used instead. Alternatively, you can specify a source for your test, which disables the behavior of finding a default one.

45.3.24 Using Spock to Test Spring Boot Applications
If you wish to use Spock to test a Spring Boot application, you should add a dependency on Spock’s spock-spring module to your application’s
build. spock-spring integrates Spring’s test framework into Spock. It is recommended that you use Spock 1.2 or later to benefit from a number of
improvements to Spock’s Spring Framework and Spring Boot integration. See the documentation for Spock’s Spring module for further details.
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45.4 Test Utilities
A few test utility classes that are generally useful when testing your application are packaged as part of spring-boot .

45.4.1 ConfigFileApplicationContextInitializer
ConfigFileApplicationContextInitializer is an ApplicationContextInitializer that you can apply to your tests to load Spring Boot
application.properties files. You can use it when you do not need the full set of features provided by @SpringBootTest , as shown in the
following example:
@ContextConfiguration(classes = Config.class,
initializers = ConfigFileApplicationContextInitializer.class)

Using ConfigFileApplicationContextInitializer alone does not provide support for @Value("${…}") injection. Its only job is
to ensure that application.properties files are loaded into Spring’s Environment . For @Value support, you need to either
additionally configure a PropertySourcesPlaceholderConfigurer or use @SpringBootTest , which auto-configures one for you.

45.4.2 TestPropertyValues
TestPropertyValues lets you quickly add properties to a ConfigurableEnvironment or ConfigurableApplicationContext . You can call it
with key=value strings, as follows:
TestPropertyValues.of("org=Spring", "name=Boot").applyTo(env);

45.4.3 OutputCapture
OutputCapture is a JUnit Rule that you can use to capture System.out and System.err output. You can declare the capture as a @Rule and
then use toString() for assertions, as follows:
import org.junit.Rule;
import org.junit.Test;
import org.springframework.boot.test.rule.OutputCapture;
import static org.hamcrest.Matchers.*;
import static org.junit.Assert.*;
public class MyTest {
@Rule
public OutputCapture capture = new OutputCapture();
@Test
public void testName() throws Exception {
System.out.println("Hello World!");
assertThat(capture.toString(), containsString("World"));
}
}

45.4.4 TestRestTemplate
Spring Framework 5.0 provides a new WebTestClient that works for WebFlux integration tests and both WebFlux and MVC end-toend testing. It provides a fluent API for assertions, unlike TestRestTemplate .

TestRestTemplate is a convenience alternative to Spring’s RestTemplate that is useful in integration tests. You can get a vanilla template or one
that sends Basic HTTP authentication (with a username and password). In either case, the template behaves in a test-friendly way by not throwing
exceptions on server-side errors. It is recommended, but not mandatory, to use the Apache HTTP Client (version 4.3.2 or better). If you have that on

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your classpath, the TestRestTemplate responds by configuring the client appropriately. If you do use Apache’s HTTP client, some additional testfriendly features are enabled:
Redirects are not followed (so you can assert the response location).
Cookies are ignored (so the template is stateless).
TestRestTemplate can be instantiated directly in your integration tests, as shown in the following example:
public class MyTest {
private TestRestTemplate template = new TestRestTemplate();
@Test
public void testRequest() throws Exception {
HttpHeaders headers = this.template.getForEntity(
"http://myhost.example.com/example", String.class).getHeaders();
assertThat(headers.getLocation()).hasHost("other.example.com");
}
}

Alternatively, if you use the @SpringBootTest annotation with WebEnvironment.RANDOM_PORT or WebEnvironment.DEFINED_PORT , you can
inject a fully configured TestRestTemplate and start using it. If necessary, additional customizations can be applied through the
RestTemplateBuilder bean. Any URLs that do not specify a host and port automatically connect to the embedded server, as shown in the
following example:
@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
public class SampleWebClientTests {
@Autowired
private TestRestTemplate template;
@Test
public void testRequest() {
HttpHeaders headers = this.template.getForEntity("/example", String.class)
.getHeaders();
assertThat(headers.getLocation()).hasHost("other.example.com");
}
@TestConfiguration
static class Config {
@Bean
public RestTemplateBuilder restTemplateBuilder() {
return new RestTemplateBuilder().setConnectTimeout(Duration.ofSeconds(1))
.setReadTimeout(Duration.ofSeconds(1));
}
}
}

46. WebSockets
Spring Boot provides WebSockets auto-configuration for embedded Tomcat, Jetty, and Undertow. If you deploy a war file to a standalone container,
Spring Boot assumes that the container is responsible for the configuration of its WebSocket support.
Spring Framework provides rich WebSocket support for MVC web applications that can be easily accessed through the
spring-boot-starter-websocket module.
WebSocket support is also available for reactive web applications and requires to include the WebSocket API alongside
spring-boot-starter-webflux :

javax.websocket

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javax.websocket-api


47. Web Services
Spring Boot provides Web Services auto-configuration so that all you must do is define your Endpoints .
The Spring Web Services features can be easily accessed with the spring-boot-starter-webservices module.
SimpleWsdl11Definition and SimpleXsdSchema beans can be automatically created for your WSDLs and XSDs respectively. To do so,
configure their location, as shown in the following example:
spring.webservices.wsdl-locations=classpath:/wsdl

48. Calling Web Services with WebServiceTemplate
If you need to call remote Web services from your application, you can use the WebServiceTemplate class. Since WebServiceTemplate
instances often need to be customized before being used, Spring Boot does not provide any single auto-configured WebServiceTemplate bean. It
does, however, auto-configure a WebServiceTemplateBuilder , which can be used to create WebServiceTemplate instances when needed.
The following code shows a typical example:
@Service
public class MyService {
private final WebServiceTemplate webServiceTemplate;
public MyService(WebServiceTemplateBuilder webServiceTemplateBuilder) {
this.webServiceTemplate = webServiceTemplateBuilder.build();
}
public DetailsResp someWsCall(DetailsReq detailsReq) {
return (DetailsResp) this.webServiceTemplate.marshalSendAndReceive(detailsReq, new SoapActionCallback(ACTION)
}
}

By default, WebServiceTemplateBuilder detects a suitable HTTP-based WebServiceMessageSender using the available HTTP client libraries
on the classpath. You can also customize read and connection timeouts as follows:
@Bean
public WebServiceTemplate webServiceTemplate(WebServiceTemplateBuilder builder) {
return builder.messageSenders(new HttpWebServiceMessageSenderBuilder()
.setConnectTimeout(5000).setReadTimeout(2000).build()).build();
}

49. Creating Your Own Auto-configuration
If you work in a company that develops shared libraries, or if you work on an open-source or commercial library, you might want to develop your own
auto-configuration. Auto-configuration classes can be bundled in external jars and still be picked-up by Spring Boot.
Auto-configuration can be associated to a “starter” that provides the auto-configuration code as well as the typical libraries that you would use with it.
We first cover what you need to know to build your own auto-configuration and then we move on to the typical steps required to create a custom
starter.

A demo project is available to showcase how you can create a starter step-by-step.

49.1 Understanding Auto-configured Beans
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Under the hood, auto-configuration is implemented with standard @Configuration classes. Additional @Conditional annotations are used to
constrain when the auto-configuration should apply. Usually, auto-configuration classes use @ConditionalOnClass and
@ConditionalOnMissingBean annotations. This ensures that auto-configuration applies only when relevant classes are found and when you have
not declared your own @Configuration .
You can browse the source code of spring-boot-autoconfigure to see the @Configuration classes that Spring provides (see the
META-INF/spring.factories file).

49.2 Locating Auto-configuration Candidates
Spring Boot checks for the presence of a META-INF/spring.factories file within your published jar. The file should list your configuration classes
under the EnableAutoConfiguration key, as shown in the following example:
org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
com.mycorp.libx.autoconfigure.LibXAutoConfiguration,\
com.mycorp.libx.autoconfigure.LibXWebAutoConfiguration

You can use the @AutoConfigureAfter or @AutoConfigureBefore annotations if your configuration needs to be applied in a specific order. For
example, if you provide web-specific configuration, your class may need to be applied after WebMvcAutoConfiguration .
If you want to order certain auto-configurations that should not have any direct knowledge of each other, you can also use @AutoConfigureOrder .
That annotation has the same semantic as the regular @Order annotation but provides a dedicated order for auto-configuration classes.

Auto-configurations must be loaded that way only. Make sure that they are defined in a specific package space and that, in particular,
they are never the target of component scanning.

49.3 Condition Annotations
You almost always want to include one or more @Conditional annotations on your auto-configuration class. The @ConditionalOnMissingBean
annotation is one common example that is used to allow developers to override auto-configuration if they are not happy with your defaults.
Spring Boot includes a number of @Conditional annotations that you can reuse in your own code by annotating @Configuration classes or
individual @Bean methods. These annotations include:
Section 49.3.1, “Class Conditions”
Section 49.3.2, “Bean Conditions”
Section 49.3.3, “Property Conditions”
Section 49.3.4, “Resource Conditions”
Section 49.3.5, “Web Application Conditions”
Section 49.3.6, “SpEL Expression Conditions”

49.3.1 Class Conditions
The @ConditionalOnClass and @ConditionalOnMissingClass annotations let configuration be included based on the presence or absence of
specific classes. Due to the fact that annotation metadata is parsed by using ASM, you can use the value attribute to refer to the real class, even
though that class might not actually appear on the running application classpath. You can also use the name attribute if you prefer to specify the
class name by using a String value.

If you use @ConditionalOnClass or @ConditionalOnMissingClass as a part of a meta-annotation to compose your own
composed annotations, you must use name as referring to the class in such a case is not handled.

49.3.2 Bean Conditions
The @ConditionalOnBean and @ConditionalOnMissingBean annotations let a bean be included based on the presence or absence of specific
beans. You can use the value attribute to specify beans by type or name to specify beans by name. The search attribute lets you limit the
ApplicationContext hierarchy that should be considered when searching for beans.

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When placed on a @Bean method, the target type defaults to the return type of the method, as shown in the following example:
@Configuration
public class MyAutoConfiguration {
@Bean
@ConditionalOnMissingBean
public MyService myService() { ... }
}

In the preceding example, the myService bean is going to be created if no bean of type MyService is already contained in the
ApplicationContext .

You need to be very careful about the order in which bean definitions are added, as these conditions are evaluated based on what has
been processed so far. For this reason, we recommend using only @ConditionalOnBean and @ConditionalOnMissingBean
annotations on auto-configuration classes (since these are guaranteed to load after any user-defined bean definitions have been
added).

@ConditionalOnBean and @ConditionalOnMissingBean do not prevent @Configuration classes from being created. The only
difference between using these conditions at the class level and marking each contained @Bean method with the annotation is that
the former prevents registration of the @Configuration class as a bean if the condition does not match.

49.3.3 Property Conditions
The @ConditionalOnProperty annotation lets configuration be included based on a Spring Environment property. Use the prefix and name
attributes to specify the property that should be checked. By default, any property that exists and is not equal to false is matched. You can also
create more advanced checks by using the havingValue and matchIfMissing attributes.

49.3.4 Resource Conditions
The @ConditionalOnResource annotation lets configuration be included only when a specific resource is present. Resources can be specified by
using the usual Spring conventions, as shown in the following example: file:/home/user/test.dat .

49.3.5 Web Application Conditions
The @ConditionalOnWebApplication and @ConditionalOnNotWebApplication annotations let configuration be included depending on
whether the application is a “web application”. A web application is any application that uses a Spring WebApplicationContext , defines a
session scope, or has a StandardServletEnvironment .

49.3.6 SpEL Expression Conditions
The @ConditionalOnExpression annotation lets configuration be included based on the result of a SpEL expression.

49.4 Testing your Auto-configuration
An auto-configuration can be affected by many factors: user configuration ( @Bean definition and Environment customization), condition evaluation
(presence of a particular library), and others. Concretely, each test should create a well defined ApplicationContext that represents a
combination of those customizations. ApplicationContextRunner provides a great way to achieve that.
ApplicationContextRunner is usually defined as a field of the test class to gather the base, common configuration. The following example makes
sure that UserServiceAutoConfiguration is always invoked:
private final ApplicationContextRunner contextRunner = new ApplicationContextRunner()
.withConfiguration(AutoConfigurations.of(UserServiceAutoConfiguration.class));

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If multiple auto-configurations have to be defined, there is no need to order their declarations as they are invoked in the exact same
order as when running the application.

Each test can use the runner to represent a particular use case. For instance, the sample below invokes a user configuration
( UserConfiguration ) and checks that the auto-configuration backs off properly. Invoking run provides a callback context that can be used with
Assert4J .
@Test
public void defaultServiceBacksOff() {
this.contextRunner.withUserConfiguration(UserConfiguration.class)
.run((context) -> {
assertThat(context).hasSingleBean(UserService.class);
assertThat(context.getBean(UserService.class)).isSameAs(
context.getBean(UserConfiguration.class).myUserService());
});
}
@Configuration
static class UserConfiguration {
@Bean
public UserService myUserService() {
return new UserService("mine");
}
}

It is also possible to easily customize the Environment , as shown in the following example:
@Test
public void serviceNameCanBeConfigured() {
this.contextRunner.withPropertyValues("user.name=test123").run((context) -> {
assertThat(context).hasSingleBean(UserService.class);
assertThat(context.getBean(UserService.class).getName()).isEqualTo("test123");
});
}

The runner can also be used to display the ConditionEvaluationReport . The report can be printed at INFO or DEBUG level. The following
example shows how to use the ConditionEvaluationReportLoggingListener to print the report in auto-configuration tests.
@Test
public void autoConfigTest {
ConditionEvaluationReportLoggingListener initializer = new ConditionEvaluationReportLoggingListener(
LogLevel.INFO);
ApplicationContextRunner contextRunner = new ApplicationContextRunner()
.withInitializer(initializer).run((context) -> {
// Do something...
});
}

49.4.1 Simulating a Web Context
If you need to test an auto-configuration that only operates in a Servlet or Reactive web application context, use the
WebApplicationContextRunner or ReactiveWebApplicationContextRunner respectively.

49.4.2 Overriding the Classpath
It is also possible to test what happens when a particular class and/or package is not present at runtime. Spring Boot ships with a
FilteredClassLoader that can easily be used by the runner. In the following example, we assert that if UserService is not present, the autoconfiguration is properly disabled:
@Test
public void serviceIsIgnoredIfLibraryIsNotPresent() {
this.contextRunner.withClassLoader(new FilteredClassLoader(UserService.class))
run((context) > assertThat(context) doesNotHaveBean("userService"));

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.run((context) -> assertThat(context).doesNotHaveBean("userService"));

}

49.5 Creating Your Own Starter
A full Spring Boot starter for a library may contain the following components:
The autoconfigure module that contains the auto-configuration code.
The starter module that provides a dependency to the autoconfigure module as well as the library and any additional dependencies that
are typically useful. In a nutshell, adding the starter should provide everything needed to start using that library.

You may combine the auto-configuration code and the dependency management in a single module if you do not need to separate
those two concerns.

49.5.1 Naming
You should make sure to provide a proper namespace for your starter. Do not start your module names with spring-boot , even if you use a
different Maven groupId . We may offer official support for the thing you auto-configure in the future.
As a rule of thumb, you should name a combined module after the starter. For example, assume that you are creating a starter for "acme" and that
you name the auto-configure module acme-spring-boot-autoconfigure and the starter acme-spring-boot-starter . If you only have one
module that combines the two, name it acme-spring-boot-starter .
Also, if your starter provides configuration keys, use a unique namespace for them. In particular, do not include your keys in the namespaces that
Spring Boot uses (such as server , management , spring , and so on). If you use the same namespace, we may modify these namespaces in the
future in ways that break your modules.
Make sure to trigger meta-data generation so that IDE assistance is available for your keys as well. You may want to review the generated metadata ( META-INF/spring-configuration-metadata.json ) to make sure your keys are properly documented.

49.5.2 autoconfigure Module
The autoconfigure module contains everything that is necessary to get started with the library. It may also contain configuration key definitions
(such as @ConfigurationProperties ) and any callback interface that can be used to further customize how the components are initialized.

You should mark the dependencies to the library as optional so that you can include the autoconfigure module in your projects
more easily. If you do it that way, the library is not provided and, by default, Spring Boot backs off.

Spring Boot uses an annotation processor to collect the conditions on auto-configurations in a metadata file
( META-INF/spring-autoconfigure-metadata.properties ). If that file is present, it is used to eagerly filter auto-configurations that do not
match, which will improve startup time. It is recommended to add the following dependency in a module that contains auto-configurations:

org.springframework.boot
spring-boot-autoconfigure-processor
true


With Gradle 4.5 and earlier, the dependency should be declared in the compileOnly configuration, as shown in the following example:
dependencies {
compileOnly "org.springframework.boot:spring-boot-autoconfigure-processor"
}

With Gradle 4.6 and later, the dependency should be declared in the annotationProcessor configuration, as shown in the following example:
dependencies {
annotationProcessor "org.springframework.boot:spring-boot-autoconfigure-processor"
}

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49.5.3 Starter Module
The starter is really an empty jar. Its only purpose is to provide the necessary dependencies to work with the library. You can think of it as an
opinionated view of what is required to get started.
Do not make assumptions about the project in which your starter is added. If the library you are auto-configuring typically requires other starters,
mention them as well. Providing a proper set of default dependencies may be hard if the number of optional dependencies is high, as you should
avoid including dependencies that are unnecessary for a typical usage of the library. In other words, you should not include optional dependencies.

Either way, your starter must reference the core Spring Boot starter ( spring-boot-starter ) directly or indirectly (i.e. no need to add
it if your starter relies on another starter). If a project is created with only your custom starter, Spring Boot’s core features will be
honoured by the presence of the core starter.

50. Kotlin support
Kotlin is a statically-typed language targeting the JVM (and other platforms) which allows writing concise and elegant code while providing
interoperability with existing libraries written in Java.
Spring Boot provides Kotlin support by leveraging the support in other Spring projects such as Spring Framework, Spring Data, and Reactor. See
the Spring Framework Kotlin support documentation for more information.
The easiest way to start with Spring Boot and Kotlin is to follow this comprehensive tutorial. You can create new Kotlin projects via start.spring.io.
Feel free to join the #spring channel of Kotlin Slack or ask a question with the spring and kotlin tags on Stack Overflow if you need support.

50.1 Requirements
Spring Boot supports Kotlin 1.2.x. To use Kotlin, org.jetbrains.kotlin:kotlin-stdlib and org.jetbrains.kotlin:kotlin-reflect must
be present on the classpath. The kotlin-stdlib variants kotlin-stdlib-jdk7 and kotlin-stdlib-jdk8 can also be used.
Since Kotlin classes are final by default, you are likely to want to configure kotlin-spring plugin in order to automatically open Spring-annotated
classes so that they can be proxied.
Jackson’s Kotlin module is required for serializing / deserializing JSON data in Kotlin. It is automatically registered when found on the classpath. A
warning message is logged if Jackson and Kotlin are present but the Jackson Kotlin module is not.

These dependencies and plugins are provided by default if one bootstraps a Kotlin project on start.spring.io.

50.2 Null-safety
One of Kotlin’s key features is null-safety. It deals with null values at compile time rather than deferring the problem to runtime and encountering a
NullPointerException . This helps to eliminate a common source of bugs without paying the cost of wrappers like Optional . Kotlin also allows
using functional constructs with nullable values as described in this comprehensive guide to null-safety in Kotlin.
Although Java does not allow one to express null-safety in its type system, Spring Framework, Spring Data, and Reactor now provide null-safety of
their API via tooling-friendly annotations. By default, types from Java APIs used in Kotlin are recognized as platform types for which null-checks are
relaxed. Kotlin’s support for JSR 305 annotations combined with nullability annotations provide null-safety for the related Spring API in Kotlin.
The JSR 305 checks can be configured by adding the -Xjsr305 compiler flag with the following options: -Xjsr305={strict|warn|ignore} . The
default behavior is the same as -Xjsr305=warn . The strict value is required to have null-safety taken in account in Kotlin types inferred from
Spring API but should be used with the knowledge that Spring API nullability declaration could evolve even between minor releases and more
checks may be added in the future).

Generic type arguments, varargs and array elements nullability are not yet supported. See SPR-15942 for up-to-date information. Also
be aware that Spring Boot’s own API is not yet annotated.

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50.3 Kotlin API
50.3.1 runApplication
Spring Boot provides an idiomatic way to run an application with runApplication(*args) as shown in the following example:
import org.springframework.boot.autoconfigure.SpringBootApplication
import org.springframework.boot.runApplication
@SpringBootApplication
class MyApplication
fun main(args: Array) {
runApplication(*args)
}

This is a drop-in replacement for SpringApplication.run(MyApplication::class.java, *args) . It also allows customization of the
application as shown in the following example:
runApplication(*args) {
setBannerMode(OFF)
}

50.3.2 Extensions
Kotlin extensions provide the ability to extend existing classes with additional functionality. The Spring Boot Kotlin API makes use of these
extensions to add new Kotlin specific conveniences to existing APIs.
TestRestTemplate extensions, similar to those provided by Spring Framework for RestOperations in Spring Framework, are provided. Among
other things, the extensions make it possible to take advantage of Kotlin reified type parameters.

50.4 Dependency management
In order to avoid mixing different version of Kotlin dependencies on the classpath, dependency management of the following Kotlin dependencies is
provided:
kotlin-reflect
kotlin-runtime
kotlin-stdlib
kotlin-stdlib-jdk7
kotlin-stdlib-jdk8
kotlin-stdlib-jre7
kotlin-stdlib-jre8
With Maven, the Kotlin version can be customized via the kotlin.version property and plugin management is provided for
kotlin-maven-plugin . With Gradle, the Spring Boot plugin automatically aligns the kotlin.version with the version of the Kotlin plugin.

50.5 @ConfigurationProperties
@ConfigurationProperties currently only works with lateinit or nullable var properties (the former is recommended), since immutable
classes initialized by constructors are not yet supported.
@ConfigurationProperties("example.kotlin")
class KotlinExampleProperties {
lateinit var name: String
lateinit var description: String
val myService = MyService()

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class MyService {
lateinit var apiToken: String
lateinit var uri: URI
}

}

To generate your own metadata using the annotation processor, kapt should be configured with the
spring-boot-configuration-processor dependency.

50.6 Testing
While it is possible to use JUnit 4 (the default provided by spring-boot-starter-test ) to test Kotlin code, JUnit 5 is recommended. JUnit 5
enables a test class to be instantiated once and reused for all of the class’s tests. This makes it possible to use @BeforeAll and @AfterAll
annotations on non-static methods, which is a good fit for Kotlin.
To use JUnit 5, exclude junit:junit dependency from spring-boot-starter-test , add JUnit 5 dependencies, and configure the Maven or
Gradle plugin accordingly. See the JUnit 5 documentation for more details. You also need to switch test instance lifecycle to "per-class".

50.7 Resources
50.7.1 Further reading
Kotlin language reference
Kotlin Slack (with a dedicated #spring channel)
Stackoverflow with spring and kotlin tags
Try Kotlin in your browser
Kotlin blog
Awesome Kotlin
Tutorial: building web applications with Spring Boot and Kotlin
Developing Spring Boot applications with Kotlin
A Geospatial Messenger with Kotlin, Spring Boot and PostgreSQL
Introducing Kotlin support in Spring Framework 5.0
Spring Framework 5 Kotlin APIs, the functional way

50.7.2 Examples
spring-boot-kotlin-demo: regular Spring Boot + Spring Data JPA project
mixit: Spring Boot 2 + WebFlux + Reactive Spring Data MongoDB
spring-kotlin-fullstack: WebFlux Kotlin fullstack example with Kotlin2js for frontend instead of JavaScript or TypeScript
spring-petclinic-kotlin: Kotlin version of the Spring PetClinic Sample Application
spring-kotlin-deepdive: a step by step migration for Boot 1.0 + Java to Boot 2.0 + Kotlin

51. What to Read Next
If you want to learn more about any of the classes discussed in this section, you can check out the Spring Boot API documentation or you can
browse the source code directly. If you have specific questions, take a look at the how-to section.
If you are comfortable with Spring Boot’s core features, you can continue on and read about production-ready features.

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Part V. Spring Boot Actuator: Production-ready features
Spring Boot includes a number of additional features to help you monitor and manage your application when you push it to production. You can
choose to manage and monitor your application by using HTTP endpoints or with JMX. Auditing, health, and metrics gathering can also be
automatically applied to your application.

52. Enabling Production-ready Features
The spring-boot-actuator module provides all of Spring Boot’s production-ready features. The simplest way to enable the features is to add a
dependency to the spring-boot-starter-actuator ‘Starter’.
Definition of Actuator
An actuator is a manufacturing term that refers to a mechanical device for moving or controlling something. Actuators can generate a large
amount of motion from a small change.
To add the actuator to a Maven based project, add the following ‘Starter’ dependency:


org.springframework.boot
spring-boot-starter-actuator



For Gradle, use the following declaration:
dependencies {
compile("org.springframework.boot:spring-boot-starter-actuator")
}

53. Endpoints
Actuator endpoints let you monitor and interact with your application. Spring Boot includes a number of built-in endpoints and lets you add your own.
For example, the health endpoint provides basic application health information.
Each individual endpoint can be enabled or disabled. This controls whether or not the endpoint is created and its bean exists in the application
context. To be remotely accessible an endpoint also has to be exposed via JMX or HTTP. Most applications choose HTTP, where the ID of the
endpoint along with a prefix of /actuator is mapped to a URL. For example, by default, the health endpoint is mapped to /actuator/health .
The following technology-agnostic endpoints are available:
ID

Description

Enabled
by default

auditevents

Exposes audit events information for the current application.

Yes

beans

Displays a complete list of all the Spring beans in your application.

Yes

caches

Exposes available caches.

Yes

conditions

Shows the conditions that were evaluated on configuration and auto-configuration classes and the

Yes

reasons why they did or did not match.
configprops

Displays a collated list of all @ConfigurationProperties .

Yes

env

Exposes properties from Spring’s ConfigurableEnvironment .

Yes

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ID

Description

Enabled
by default

flyway

Shows any Flyway database migrations that have been applied.

Yes

health

Shows application health information.

Yes

httptrace

Displays HTTP trace information (by default, the last 100 HTTP request-response exchanges).

Yes

info

Displays arbitrary application info.

Yes

integrationgraph

Shows the Spring Integration graph.

Yes

loggers

Shows and modifies the configuration of loggers in the application.

Yes

liquibase

Shows any Liquibase database migrations that have been applied.

Yes

metrics

Shows ‘metrics’ information for the current application.

Yes

mappings

Displays a collated list of all @RequestMapping paths.

Yes

scheduledtasks

Displays the scheduled tasks in your application.

Yes

sessions

Allows retrieval and deletion of user sessions from a Spring Session-backed session store. Not available

Yes

when using Spring Session’s support for reactive web applications.
shutdown

Lets the application be gracefully shutdown.

No

threaddump

Performs a thread dump.

Yes

If your application is a web application (Spring MVC, Spring WebFlux, or Jersey), you can use the following additional endpoints:
ID

Description

Enabled
by default

heapdump

Returns an hprof heap dump file.

Yes

jolokia

Exposes JMX beans over HTTP (when Jolokia is on the classpath, not available for WebFlux).

Yes

logfile

Returns the contents of the logfile (if logging.file or logging.path properties have been set). Supports

Yes

the use of the HTTP Range header to retrieve part of the log file’s content.
prometheus

Exposes metrics in a format that can be scraped by a Prometheus server.

Yes

To learn more about the Actuator’s endpoints and their request and response formats, please refer to the separate API documentation (HTML or
PDF).

53.1 Enabling Endpoints
By default, all endpoints except for shutdown are enabled. To configure the enablement of an endpoint, use its
management.endpoint..enabled property. The following example enables the shutdown endpoint:
management.endpoint.shutdown.enabled=true

If you prefer endpoint enablement to be opt-in rather than opt-out, set the management.endpoints.enabled-by-default property to false and
use individual endpoint enabled properties to opt back in. The following example enables the info endpoint and disables all other endpoints:

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management.endpoints.enabled-by-default=false
management.endpoint.info.enabled=true

Disabled endpoints are removed entirely from the application context. If you want to change only the technologies over which an
endpoint is exposed, use the include and exclude properties instead.

53.2 Exposing Endpoints
Since Endpoints may contain sensitive information, careful consideration should be given about when to expose them. The following table shows the
default exposure for the built-in endpoints:
ID

JMX

Web

auditevents

Yes

No

beans

Yes

No

caches

Yes

No

conditions

Yes

No

configprops

Yes

No

env

Yes

No

flyway

Yes

No

health

Yes

Yes

heapdump

N/A

No

httptrace

Yes

No

info

Yes

Yes

integrationgraph

Yes

No

jolokia

N/A

No

logfile

N/A

No

loggers

Yes

No

liquibase

Yes

No

metrics

Yes

No

mappings

Yes

No

prometheus

N/A

No

scheduledtasks

Yes

No

sessions

Yes

No

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ID

JMX

Web

shutdown

Yes

No

threaddump

Yes

No

To change which endpoints are exposed, use the following technology-specific include and exclude properties:
Property

Default

management.endpoints.jmx.exposure.exclude
management.endpoints.jmx.exposure.include

*

management.endpoints.web.exposure.exclude
management.endpoints.web.exposure.include

info, health

The include property lists the IDs of the endpoints that are exposed. The exclude property lists the IDs of the endpoints that should not be
exposed. The exclude property takes precedence over the include property. Both include and exclude properties can be configured with a
list of endpoint IDs.
For example, to stop exposing all endpoints over JMX and only expose the health and info endpoints, use the following property:
management.endpoints.jmx.exposure.include=health,info

* can be used to select all endpoints. For example, to expose everything over HTTP except the env and beans endpoints, use the following
properties:
management.endpoints.web.exposure.include=*
management.endpoints.web.exposure.exclude=env,beans

* has a special meaning in YAML, so be sure to add quotes if you want to include (or exclude) all endpoints, as shown in the
following example:
management:
endpoints:
web:
exposure:
include: "*"

If your application is exposed publicly, we strongly recommend that you also secure your endpoints.

If you want to implement your own strategy for when endpoints are exposed, you can register an EndpointFilter bean.

53.3 Securing HTTP Endpoints
You should take care to secure HTTP endpoints in the same way that you would any other sensitive URL. If Spring Security is present, endpoints
are secured by default using Spring Security’s content-negotiation strategy. If you wish to configure custom security for HTTP endpoints, for
example, only allow users with a certain role to access them, Spring Boot provides some convenient RequestMatcher objects that can be used in
combination with Spring Security.
A typical Spring Security configuration might look something like the following example:
@Configuration
public class ActuatorSecurity extends WebSecurityConfigurerAdapter {

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@Override
protected void configure(HttpSecurity http) throws Exception {
http.requestMatcher(EndpointRequest.toAnyEndpoint()).authorizeRequests()
.anyRequest().hasRole("ENDPOINT_ADMIN")
.and()
.httpBasic();
}

}

The preceding example uses EndpointRequest.toAnyEndpoint() to match a request to any endpoint and then ensures that all have the
ENDPOINT_ADMIN role. Several other matcher methods are also available on EndpointRequest . See the API documentation (HTML or PDF) for
details.
If you deploy applications behind a firewall, you may prefer that all your actuator endpoints can be accessed without requiring authentication. You
can do so by changing the management.endpoints.web.exposure.include property, as follows:
application.properties.
management.endpoints.web.exposure.include=*

Additionally, if Spring Security is present, you would need to add custom security configuration that allows unauthenticated access to the endpoints
as shown in the following example:
@Configuration
public class ActuatorSecurity extends WebSecurityConfigurerAdapter {
@Override
protected void configure(HttpSecurity http) throws Exception {
http.requestMatcher(EndpointRequest.toAnyEndpoint()).authorizeRequests()
.anyRequest().permitAll();
}
}

53.4 Configuring Endpoints
Endpoints automatically cache responses to read operations that do not take any parameters. To configure the amount of time for which an endpoint
will cache a response, use its cache.time-to-live property. The following example sets the time-to-live of the beans endpoint’s cache to 10
seconds:
application.properties.
management.endpoint.beans.cache.time-to-live=10s

The prefix management.endpoint. is used to uniquely identify the endpoint that is being configured.

When making an authenticated HTTP request, the Principal is considered as input to the endpoint and, therefore, the response will
not be cached.

53.5 Hypermedia for Actuator Web Endpoints
A “discovery page” is added with links to all the endpoints. The “discovery page” is available on /actuator by default.
When a custom management context path is configured, the “discovery page” automatically moves from /actuator to the root of the management
context. For example, if the management context path is /management , then the discovery page is available from /management . When the
management context path is set to / , the discovery page is disabled to prevent the possibility of a clash with other mappings.

53.6 CORS Support
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Cross-origin resource sharing (CORS) is a W3C specification that lets you specify in a flexible way what kind of cross-domain requests are
authorized. If you use Spring MVC or Spring WebFlux, Actuator’s web endpoints can be configured to support such scenarios.
CORS support is disabled by default and is only enabled once the management.endpoints.web.cors.allowed-origins property has been set.
The following configuration permits GET and POST calls from the example.com domain:
management.endpoints.web.cors.allowed-origins=http://example.com
management.endpoints.web.cors.allowed-methods=GET,POST

See CorsEndpointProperties for a complete list of options.

53.7 Implementing Custom Endpoints
If you add a @Bean annotated with @Endpoint , any methods annotated with @ReadOperation , @WriteOperation , or @DeleteOperation are
automatically exposed over JMX and, in a web application, over HTTP as well. Endpoints can be exposed over HTTP using Jersey, Spring MVC, or
Spring WebFlux.
You can also write technology-specific endpoints by using @JmxEndpoint or @WebEndpoint . These endpoints are restricted to their respective
technologies. For example, @WebEndpoint is exposed only over HTTP and not over JMX.
You can write technology-specific extensions by using @EndpointWebExtension and @EndpointJmxExtension . These annotations let you
provide technology-specific operations to augment an existing endpoint.
Finally, if you need access to web-framework-specific functionality, you can implement Servlet or Spring @Controller and @RestController
endpoints at the cost of them not being available over JMX or when using a different web framework.

53.7.1 Receiving Input
Operations on an endpoint receive input via their parameters. When exposed via the web, the values for these parameters are taken from the URL’s
query parameters and from the JSON request body. When exposed via JMX, the parameters are mapped to the parameters of the MBean’s
operations. Parameters are required by default. They can be made optional by annotating them with @org.springframework.lang.Nullable .
Each root property in the JSON request body can be mapped to a parameter of the endpoint. Consider the following JSON request body:
{
"name": "test",
"counter": 42
}

This can be used to invoke a write operation that takes String name and int counter parameters.

Because endpoints are technology agnostic, only simple types can be specified in the method signature. In particular declaring a
single parameter with a custom type defining a name and counter properties is not supported.

To allow the input to be mapped to the operation method’s parameters, Java code implementing an endpoint should be compiled with
-parameters , and Kotlin code implementing an endpoint should be compiled with -java-parameters . This will happen
automatically if you are using Spring Boot’s Gradle plugin or if you are using Maven and spring-boot-starter-parent .

Input type conversion
The parameters passed to endpoint operation methods are, if necessary, automatically converted to the required type. Before calling an operation
method, the input received via JMX or an HTTP request is converted to the required types using an instance of ApplicationConversionService .

53.7.2 Custom Web Endpoints
Operations on an @Endpoint , @WebEndpoint , or @EndpointWebExtension are automatically exposed over HTTP using Jersey, Spring MVC, or
Spring WebFlux.
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Web Endpoint Request Predicates
A request predicate is automatically generated for each operation on a web-exposed endpoint.

Path
The path of the predicate is determined by the ID of the endpoint and the base path of web-exposed endpoints. The default base path is
/actuator . For example, an endpoint with the ID sessions will use /actuator/sessions as its path in the predicate.
The path can be further customized by annotating one or more parameters of the operation method with @Selector . Such a parameter is added to
the path predicate as a path variable. The variable’s value is passed into the operation method when the endpoint operation is invoked.

HTTP method
The HTTP method of the predicate is determined by the operation type, as shown in the following table:
Operation

HTTP method

@ReadOperation

GET

@WriteOperation

POST

@DeleteOperation

DELETE

Consumes
For a @WriteOperation (HTTP POST ) that uses the request body, the consumes clause of the predicate is
application/vnd.spring-boot.actuator.v2+json, application/json . For all other operations the consumes clause is empty.

Produces
The produces clause of the predicate can be determined by the produces attribute of the @DeleteOperation , @ReadOperation , and
@WriteOperation annotations. The attribute is optional. If it is not used, the produces clause is determined automatically.
If the operation method returns void or Void the produces clause is empty. If the operation method returns a
org.springframework.core.io.Resource , the produces clause is application/octet-stream . For all other operations the produces clause
is application/vnd.spring-boot.actuator.v2+json, application/json .

Web Endpoint Response Status
The default response status for an endpoint operation depends on the operation type (read, write, or delete) and what, if anything, the operation
returns.
A @ReadOperation returns a value, the response status will be 200 (OK). If it does not return a value, the response status will be 404 (Not Found).
If a @WriteOperation or @DeleteOperation returns a value, the response status will be 200 (OK). If it does not return a value the response
status will be 204 (No Content).
If an operation is invoked without a required parameter, or with a parameter that cannot be converted to the required type, the operation method will
not be called and the response status will be 400 (Bad Request).

Web Endpoint Range Requests
An HTTP range request can be used to request part of an HTTP resource. When using Spring MVC or Spring Web Flux, operations that return a
org.springframework.core.io.Resource automatically support range requests.

Range requests are not supported when using Jersey.

Web Endpoint Security

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An operation on a web endpoint or a web-specific endpoint extension can receive the current java.security.Principal or
org.springframework.boot.actuate.endpoint.SecurityContext as a method parameter. The former is typically used in conjunction with
@Nullable to provide different behaviour for authenticated and unauthenticated users. The latter is typically used to perform authorization checks
using its isUserInRole(String) method.

53.7.3 Servlet endpoints
A Servlet can be exposed as an endpoint by implementing a class annotated with @ServletEndpoint that also implements
Supplier . Servlet endpoints provide deeper integration with the Servlet container but at the expense of portability. They are
intended to be used to expose an existing Servlet as an endpoint. For new endpoints, the @Endpoint and @WebEndpoint annotations should
be preferred whenever possible.

53.7.4 Controller endpoints
@ControllerEndpoint and @RestControllerEndpoint can be used to implement an endpoint that is only exposed by Spring MVC or Spring
WebFlux. Methods are mapped using the standard annotations for Spring MVC and Spring WebFlux such as @RequestMapping and
@GetMapping , with the endpoint’s ID being used as a prefix for the path. Controller endpoints provide deeper integration with Spring’s web
frameworks but at the expense of portability. The @Endpoint and @WebEndpoint annotations should be preferred whenever possible.

53.8 Health Information
You can use health information to check the status of your running application. It is often used by monitoring software to alert someone when a
production system goes down. The information exposed by the health endpoint depends on the management.endpoint.health.show-details
property which can be configured with one of the following values:
Name

Description

never

Details are never shown.

when-authorized

Details are only shown to authorized users. Authorized roles can be configured using
management.endpoint.health.roles .

always

Details are shown to all users.

The default value is never . A user is considered to be authorized when they are in one or more of the endpoint’s roles. If the endpoint has no
configured roles (the default) all authenticated users are considered to be authorized. The roles can be configured using the
management.endpoint.health.roles property.

If you have secured your application and wish to use always , your security configuration must permit access to the health endpoint
for both authenticated and unauthenticated users.

Health information is collected from the content of a HealthIndicatorRegistry (by default all HealthIndicator instances defined in your
ApplicationContext . Spring Boot includes a number of auto-configured HealthIndicators and you can also write your own. By default, the
final system state is derived by the HealthAggregator which sorts the statuses from each HealthIndicator based on an ordered list of
statuses. The first status in the sorted list is used as the overall health status. If no HealthIndicator returns a status that is known to the
HealthAggregator , an UNKNOWN status is used.

The HealthIndicatorRegistry can be used to register and unregister health indicators at runtime.

53.8.1 Auto-configured HealthIndicators
The following HealthIndicators are auto-configured by Spring Boot when appropriate:
Name

Description

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Name

Description

CassandraHealthIndicator

Checks that a Cassandra database is up.

CouchbaseHealthIndicator

Checks that a Couchbase cluster is up.

DiskSpaceHealthIndicator

Checks for low disk space.

DataSourceHealthIndicator

Checks that a connection to DataSource can be obtained.

ElasticsearchHealthIndicator

Checks that an Elasticsearch cluster is up.

InfluxDbHealthIndicator

Checks that an InfluxDB server is up.

JmsHealthIndicator

Checks that a JMS broker is up.

MailHealthIndicator

Checks that a mail server is up.

MongoHealthIndicator

Checks that a Mongo database is up.

Neo4jHealthIndicator

Checks that a Neo4j server is up.

RabbitHealthIndicator

Checks that a Rabbit server is up.

RedisHealthIndicator

Checks that a Redis server is up.

SolrHealthIndicator

Checks that a Solr server is up.

You can disable them all by setting the management.health.defaults.enabled property.

53.8.2 Writing Custom HealthIndicators
To provide custom health information, you can register Spring beans that implement the HealthIndicator interface. You need to provide an
implementation of the health() method and return a Health response. The Health response should include a status and can optionally include
additional details to be displayed. The following code shows a sample HealthIndicator implementation:
import org.springframework.boot.actuate.health.Health;
import org.springframework.boot.actuate.health.HealthIndicator;
import org.springframework.stereotype.Component;
@Component
public class MyHealthIndicator implements HealthIndicator {
@Override
public Health health() {
int errorCode = check(); // perform some specific health check
if (errorCode != 0) {
return Health.down().withDetail("Error Code", errorCode).build();
}
return Health.up().build();
}
}

The identifier for a given HealthIndicator is the name of the bean without the HealthIndicator suffix, if it exists. In the
preceding example, the health information is available in an entry named my .

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In addition to Spring Boot’s predefined Status types, it is also possible for Health to return a custom Status that represents a new system
state. In such cases, a custom implementation of the HealthAggregator interface also needs to be provided, or the default implementation has to
be configured by using the management.health.status.order configuration property.
For example, assume a new Status with code FATAL is being used in one of your HealthIndicator implementations. To configure the severity
order, add the following property to your application properties:
management.health.status.order=FATAL, DOWN, OUT_OF_SERVICE, UNKNOWN, UP

The HTTP status code in the response reflects the overall health status (for example, UP maps to 200, while OUT_OF_SERVICE and DOWN map to
503). You might also want to register custom status mappings if you access the health endpoint over HTTP. For example, the following property
maps FATAL to 503 (service unavailable):
management.health.status.http-mapping.FATAL=503

If you need more control, you can define your own HealthStatusHttpMapper bean.

The following table shows the default status mappings for the built-in statuses:
Status

Mapping

DOWN

SERVICE_UNAVAILABLE (503)

OUT_OF_SERVICE

SERVICE_UNAVAILABLE (503)

UP

No mapping by default, so http status is 200

UNKNOWN

No mapping by default, so http status is 200

53.8.3 Reactive Health Indicators
For reactive applications, such as those using Spring WebFlux, ReactiveHealthIndicator provides a non-blocking contract for getting
application health. Similar to a traditional HealthIndicator , health information is collected from the content of a
ReactiveHealthIndicatorRegistry (by default all HealthIndicator and ReactiveHealthIndicator instances defined in your
ApplicationContext . Regular HealthIndicator that do not check against a reactive API are executed on the elastic scheduler.

In a reactive application, The ReactiveHealthIndicatorRegistry can be used to register and unregister health indicators at
runtime.

To provide custom health information from a reactive API, you can register Spring beans that implement the ReactiveHealthIndicator interface.
The following code shows a sample ReactiveHealthIndicator implementation:
@Component
public class MyReactiveHealthIndicator implements ReactiveHealthIndicator {
@Override
public Mono health() {
return doHealthCheck() //perform some specific health check that returns a Mono
.onErrorResume(ex -> Mono.just(new Health.Builder().down(ex).build())));
}

}

To handle the error automatically, consider extending from AbstractReactiveHealthIndicator .

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53.8.4 Auto-configured ReactiveHealthIndicators
The following ReactiveHealthIndicators are auto-configured by Spring Boot when appropriate:
Name

Description

CassandraReactiveHealthIndicator

Checks that a Cassandra database is up.

CouchbaseReactiveHealthIndicator

Checks that a Couchbase cluster is up.

MongoReactiveHealthIndicator

Checks that a Mongo database is up.

RedisReactiveHealthIndicator

Checks that a Redis server is up.

If necessary, reactive indicators replace the regular ones. Also, any HealthIndicator that is not handled explicitly is wrapped
automatically.

53.9 Application Information
Application information exposes various information collected from all InfoContributor beans defined in your ApplicationContext . Spring
Boot includes a number of auto-configured InfoContributor beans, and you can write your own.

53.9.1 Auto-configured InfoContributors
The following InfoContributor beans are auto-configured by Spring Boot, when appropriate:
Name

Description

EnvironmentInfoContributor

Exposes any key from the Environment under the info key.

GitInfoContributor

Exposes git information if a git.properties file is available.

BuildInfoContributor

Exposes build information if a META-INF/build-info.properties file is available.

It is possible to disable them all by setting the management.info.defaults.enabled property.

53.9.2 Custom Application Information
You can customize the data exposed by the info endpoint by setting info.* Spring properties. All Environment properties under the info key
are automatically exposed. For example, you could add the following settings to your application.properties file:
info.app.encoding=UTF-8
info.app.java.source=1.8
info.app.java.target=1.8

Rather than hardcoding those values, you could also expand info properties at build time.
Assuming you use Maven, you could rewrite the preceding example as follows:
info.app.encoding=@project.build.sourceEncoding@
info.app.java.source=@java.version@
info.app.java.target=@java.version@

53.9.3 Git Commit Information
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Another useful feature of the info endpoint is its ability to publish information about the state of your git source code repository when the project
was built. If a GitProperties bean is available, the git.branch , git.commit.id , and git.commit.time properties are exposed.

A GitProperties bean is auto-configured if a git.properties file is available at the root of the classpath. See "Generate git
information" for more details.

If you want to display the full git information (that is, the full content of git.properties ), use the management.info.git.mode property, as
follows:
management.info.git.mode=full

53.9.4 Build Information
If a BuildProperties bean is available, the info endpoint can also publish information about your build. This happens if a
META-INF/build-info.properties file is available in the classpath.

The Maven and Gradle plugins can both generate that file. See "Generate build information" for more details.

53.9.5 Writing Custom InfoContributors
To provide custom application information, you can register Spring beans that implement the InfoContributor interface.
The following example contributes an example entry with a single value:
import java.util.Collections;
import org.springframework.boot.actuate.info.Info;
import org.springframework.boot.actuate.info.InfoContributor;
import org.springframework.stereotype.Component;
@Component
public class ExampleInfoContributor implements InfoContributor {
@Override
public void contribute(Info.Builder builder) {
builder.withDetail("example",
Collections.singletonMap("key", "value"));
}
}

If you reach the info endpoint, you should see a response that contains the following additional entry:
{
"example": {
"key" : "value"
}
}

54. Monitoring and Management over HTTP
If you are developing a web application, Spring Boot Actuator auto-configures all enabled endpoints to be exposed over HTTP. The default
convention is to use the id of the endpoint with a prefix of /actuator as the URL path. For example, health is exposed as
/actuator/health . TIP: Actuator is supported natively with Spring MVC, Spring WebFlux, and Jersey.

54.1 Customizing the Management Endpoint Paths

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Sometimes, it is useful to customize the prefix for the management endpoints. For example, your application might already use /actuator for
another purpose. You can use the management.endpoints.web.base-path property to change the prefix for your management endpoint, as
shown in the following example:
management.endpoints.web.base-path=/manage

The preceding application.properties example changes the endpoint from /actuator/{id} to /manage/{id} (for example,
/manage/info ).

Unless the management port has been configured to expose endpoints by using a different HTTP port,
management.endpoints.web.base-path is relative to server.servlet.context-path . If management.server.port is
configured, management.endpoints.web.base-path is relative to management.server.servlet.context-path .

If you want to map endpoints to a different path, you can use the management.endpoints.web.path-mapping property.
The following example remaps /actuator/health to /healthcheck :
application.properties.
management.endpoints.web.base-path=/
management.endpoints.web.path-mapping.health=healthcheck

54.2 Customizing the Management Server Port
Exposing management endpoints by using the default HTTP port is a sensible choice for cloud-based deployments. If, however, your application
runs inside your own data center, you may prefer to expose endpoints by using a different HTTP port.
You can set the management.server.port property to change the HTTP port, as shown in the following example:
management.server.port=8081

54.3 Configuring Management-specific SSL
When configured to use a custom port, the management server can also be configured with its own SSL by using the various
management.server.ssl.* properties. For example, doing so lets a management server be available over HTTP while the main application uses
HTTPS, as shown in the following property settings:
server.port=8443
server.ssl.enabled=true
server.ssl.key-store=classpath:store.jks
server.ssl.key-password=secret
management.server.port=8080
management.server.ssl.enabled=false

Alternatively, both the main server and the management server can use SSL but with different key stores, as follows:
server.port=8443
server.ssl.enabled=true
server.ssl.key-store=classpath:main.jks
server.ssl.key-password=secret
management.server.port=8080
management.server.ssl.enabled=true
management.server.ssl.key-store=classpath:management.jks
management.server.ssl.key-password=secret

54.4 Customizing the Management Server Address
You can customize the address that the management endpoints are available on by setting the management.server.address property. Doing so
can be useful if you want to listen only on an internal or ops-facing network or to listen only for connections from localhost .

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You can listen on a different address only when the port differs from the main server port.

The following example application.properties does not allow remote management connections:
management.server.port=8081
management.server.address=127.0.0.1

54.5 Disabling HTTP Endpoints
If you do not want to expose endpoints over HTTP, you can set the management port to -1 , as shown in the following example:
management.server.port=-1

This can be achieved using the management.endpoints.web.exposure.exclude property as well, as shown in following example:
management.endpoints.web.exposure.exclude=*

55. Monitoring and Management over JMX
Java Management Extensions (JMX) provide a standard mechanism to monitor and manage applications. By default, Spring Boot exposes
management endpoints as JMX MBeans under the org.springframework.boot domain.

55.1 Customizing MBean Names
The name of the MBean is usually generated from the id of the endpoint. For example, the health endpoint is exposed as
org.springframework.boot:type=Endpoint,name=Health .
If your application contains more than one Spring ApplicationContext , you may find that names clash. To solve this problem, you can set the
spring.jmx.unique-names property to true so that MBean names are always unique.
You can also customize the JMX domain under which endpoints are exposed. The following settings show an example of doing so in
application.properties :
spring.jmx.unique-names=true
management.endpoints.jmx.domain=com.example.myapp

55.2 Disabling JMX Endpoints
If you do not want to expose endpoints over JMX, you can set the management.endpoints.jmx.exposure.exclude property to * , as shown in
the following example:
management.endpoints.jmx.exposure.exclude=*

55.3 Using Jolokia for JMX over HTTP
Jolokia is a JMX-HTTP bridge that provides an alternative method of accessing JMX beans. To use Jolokia, include a dependency to
org.jolokia:jolokia-core . For example, with Maven, you would add the following dependency:

org.jolokia
jolokia-core


The Jolokia endpoint can then be exposed by adding jolokia or * to the management.endpoints.web.exposure.include property. You can
then access it by using /actuator/jolokia on your management HTTP server.

55.3.1 Customizing Jolokia
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Jolokia has a number of settings that you would traditionally configure by setting servlet parameters. With Spring Boot, you can use your
application.properties file. To do so, prefix the parameter with management.endpoint.jolokia.config. , as shown in the following
example:
management.endpoint.jolokia.config.debug=true

55.3.2 Disabling Jolokia
If you use Jolokia but do not want Spring Boot to configure it, set the management.endpoint.jolokia.enabled property to false , as follows:
management.endpoint.jolokia.enabled=false

56. Loggers
Spring Boot Actuator includes the ability to view and configure the log levels of your application at runtime. You can view either the entire list or an
individual logger’s configuration, which is made up of both the explicitly configured logging level as well as the effective logging level given to it by
the logging framework. These levels can be one of:
TRACE
DEBUG
INFO
WARN
ERROR
FATAL
OFF
null
null indicates that there is no explicit configuration.

56.1 Configure a Logger
To configure a given logger, POST a partial entity to the resource’s URI, as shown in the following example:
{
"configuredLevel": "DEBUG"
}

To “reset” the specific level of the logger (and use the default configuration instead), you can pass a value of null as the
configuredLevel .

57. Metrics
Spring Boot Actuator provides dependency management and auto-configuration for Micrometer, an application metrics facade that supports
numerous monitoring systems, including:
AppOptics
Atlas
Datadog
Dynatrace
Elastic
Ganglia
Graphite
Humio
Influx
JMX
KairosDB
New Relic
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Prometheus
SignalFx
Simple (in-memory)
StatsD
Wavefront

To learn more about Micrometer’s capabilities, please refer to its reference documentation, in particular the concepts section.

57.1 Getting started
Spring Boot auto-configures a composite MeterRegistry and adds a registry to the composite for each of the supported implementations that it
finds on the classpath. Having a dependency on micrometer-registry-{system} in your runtime classpath is enough for Spring Boot to
configure the registry.
Most registries share common features. For instance, you can disable a particular registry even if the Micrometer registry implementation is on the
classpath. For instance, to disable Datadog:
management.metrics.export.datadog.enabled=false

Spring Boot will also add any auto-configured registries to the global static composite registry on the Metrics class unless you explicitly tell it not
to:
management.metrics.use-global-registry=false

You can register any number of MeterRegistryCustomizer beans to further configure the registry, such as applying common tags, before any
meters are registered with the registry:
@Bean
MeterRegistryCustomizer metricsCommonTags() {
return registry -> registry.config().commonTags("region", "us-east-1");
}

You can apply customizations to particular registry implementations by being more specific about the generic type:
@Bean
MeterRegistryCustomizer graphiteMetricsNamingConvention() {
return registry -> registry.config().namingConvention(MY_CUSTOM_CONVENTION);
}

With that setup in place you can inject MeterRegistry in your components and register metrics:
@Component
public class SampleBean {
private final Counter counter;
public SampleBean(MeterRegistry registry) {
this.counter = registry.counter("received.messages");
}
public void handleMessage(String message) {
this.counter.increment();
// handle message implementation
}
}

Spring Boot also configures built-in instrumentation (i.e. MeterBinder implementations) that you can control via configuration or dedicated
annotation markers.

57.2 Supported monitoring systems
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57.2.1 AppOptics
By default, the AppOptics registry pushes metrics to api.appoptics.com/v1/measurements periodically. To export metrics to SaaS AppOptics, your
API token must be provided:
management.metrics.export.appoptics.api-token=YOUR_TOKEN

57.2.2 Atlas
By default, metrics are exported to Atlas running on your local machine. The location of the Atlas server to use can be provided using:
management.metrics.export.atlas.uri=http://atlas.example.com:7101/api/v1/publish

57.2.3 Datadog
Datadog registry pushes metrics to datadoghq periodically. To export metrics to Datadog, your API key must be provided:
management.metrics.export.datadog.api-key=YOUR_KEY

You can also change the interval at which metrics are sent to Datadog:
management.metrics.export.datadog.step=30s

57.2.4 Dynatrace
Dynatrace registry pushes metrics to the configured URI periodically. To export metrics to Dynatrace, your API token, device ID, and URI must be
provided:
management.metrics.export.dynatrace.api-token=YOUR_TOKEN
management.metrics.export.dynatrace.device-id=YOUR_DEVICE_ID
management.metrics.export.dynatrace.uri=YOUR_URI

You can also change the interval at which metrics are sent to Dynatrace:
management.metrics.export.dynatrace.step=30s

57.2.5 Elastic
By default, metrics are exported to Elastic running on your local machine. The location of the Elastic server to use can be provided using the
following property:
management.metrics.export.elastic.host=http://elastic.example.com:8086

57.2.6 Ganglia
By default, metrics are exported to Ganglia running on your local machine. The Ganglia server host and port to use can be provided using:
management.metrics.export.ganglia.host=ganglia.example.com
management.metrics.export.ganglia.port=9649

57.2.7 Graphite
By default, metrics are exported to Graphite running on your local machine. The Graphite server host and port to use can be provided using:
management.metrics.export.graphite.host=graphite.example.com
management.metrics.export.graphite.port=9004

Micrometer provides a default HierarchicalNameMapper that governs how a dimensional meter id is mapped to flat hierarchical names.

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To take control over this behaviour, define your GraphiteMeterRegistry and supply your own HierarchicalNameMapper . An
auto-configured GraphiteConfig and Clock beans are provided unless you define your own:

@Bean
public GraphiteMeterRegistry graphiteMeterRegistry(GraphiteConfig config, Clock clock) {
return new GraphiteMeterRegistry(config, clock, MY_HIERARCHICAL_MAPPER);
}

57.2.8 Humio
By default, the Humio registry pushes metrics to cloud.humio.com periodically. To export metrics to SaaS Humio, your API token must be provided:
management.metrics.export.humio.api-token=YOUR_TOKEN

You should also configure one or more tags to identify the data source to which metrics will be pushed:
management.metrics.export.humio.tags.alpha=a
management.metrics.export.humio.tags.bravo=b

57.2.9 Influx
By default, metrics are exported to Influx running on your local machine. The location of the Influx server to use can be provided using:
management.metrics.export.influx.uri=http://influx.example.com:8086

57.2.10 JMX
Micrometer provides a hierarchical mapping to JMX, primarily as a cheap and portable way to view metrics locally. By default, metrics are exported
to the metrics JMX domain. The domain to use can be provided using:
management.metrics.export.jmx.domain=com.example.app.metrics

Micrometer provides a default HierarchicalNameMapper that governs how a dimensional meter id is mapped to flat hierarchical names.

To take control over this behaviour, define your JmxMeterRegistry and supply your own HierarchicalNameMapper . An autoconfigured JmxConfig and Clock beans are provided unless you define your own:

@Bean
public JmxMeterRegistry jmxMeterRegistry(JmxConfig config, Clock clock) {
return new JmxMeterRegistry(config, clock, MY_HIERARCHICAL_MAPPER);
}

57.2.11 KairosDB
By default, metrics are exported to KairosDB running on your local machine. The location of the KairosDB server to use can be provided using:
management.metrics.export.kairos.uri=http://kairosdb.example.com:8080/api/v1/datapoints

57.2.12 New Relic
New Relic registry pushes metrics to New Relic periodically. To export metrics to New Relic, your API key and account id must be provided:
management.metrics.export.newrelic.api-key=YOUR_KEY
management.metrics.export.newrelic.account-id=YOUR_ACCOUNT_ID

You can also change the interval at which metrics are sent to New Relic:

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management.metrics.export.newrelic.step=30s

57.2.13 Prometheus
Prometheus expects to scrape or poll individual app instances for metrics. Spring Boot provides an actuator endpoint available at
/actuator/prometheus to present a Prometheus scrape with the appropriate format.

The endpoint is not available by default and must be exposed, see exposing endpoints for more details.

Here is an example scrape_config to add to prometheus.yml :
scrape_configs:
- job_name: 'spring'
metrics_path: '/actuator/prometheus'
static_configs:
- targets: ['HOST:PORT']

57.2.14 SignalFx
SignalFx registry pushes metrics to SignalFx periodically. To export metrics to SignalFx, your access token must be provided:
management.metrics.export.signalfx.access-token=YOUR_ACCESS_TOKEN

You can also change the interval at which metrics are sent to SignalFx:
management.metrics.export.signalfx.step=30s

57.2.15 Simple
Micrometer ships with a simple, in-memory backend that is automatically used as a fallback if no other registry is configured. This allows you to see
what metrics are collected in the metrics endpoint.
The in-memory backend disables itself as soon as you’re using any of the other available backend. You can also disable it explicitly:
management.metrics.export.simple.enabled=false

57.2.16 StatsD
The StatsD registry pushes metrics over UDP to a StatsD agent eagerly. By default, metrics are exported to a StatsD agent running on your local
machine. The StatsD agent host and port to use can be provided using:
management.metrics.export.statsd.host=statsd.example.com
management.metrics.export.statsd.port=9125

You can also change the StatsD line protocol to use (default to Datadog):
management.metrics.export.statsd.flavor=etsy

57.2.17 Wavefront
Wavefront registry pushes metrics to Wavefront periodically. If you are exporting metrics to Wavefront directly, your API token must be provided:
management.metrics.export.wavefront.api-token=YOUR_API_TOKEN

Alternatively, you may use a Wavefront sidecar or an internal proxy set up in your environment that forwards metrics data to the Wavefront API host:
management.metrics.export.wavefront.uri=proxy://localhost:2878

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If publishing metrics to a Wavefront proxy (as described in the documentation), the host must be in the proxy://HOST:PORT format.

You can also change the interval at which metrics are sent to Wavefront:
management.metrics.export.wavefront.step=30s

57.3 Supported Metrics
Spring Boot registers the following core metrics when applicable:
JVM metrics, report utilization of:
Various memory and buffer pools
Statistics related to garbage collection
Threads utilization
Number of classes loaded/unloaded
CPU metrics
File descriptor metrics
Kafka consumer metrics
Log4j2 metrics: record the number of events logged to Log4j2 at each level
Logback metrics: record the number of events logged to Logback at each level
Uptime metrics: report a gauge for uptime and a fixed gauge representing the application’s absolute start time
Tomcat metrics
Spring Integration metrics

57.3.1 Spring MVC Metrics
Auto-configuration enables the instrumentation of requests handled by Spring MVC. When
management.metrics.web.server.auto-time-requests is true , this instrumentation occurs for all requests. Alternatively, when set to false ,
you can enable instrumentation by adding @Timed to a request-handling method:
@RestController
@Timed
public class MyController {
@GetMapping("/api/people")
@Timed(extraTags = { "region", "us-east-1" })
@Timed(value = "all.people", longTask = true)
public List listPeople() { ... }
}

A controller class to enable timings on every request handler in the controller.
A method to enable for an individual endpoint. This is not necessary if you have it on the class, but can be used to further customize the timer
for this particular endpoint.
A method with longTask = true to enable a long task timer for the method. Long task timers require a separate metric name, and can be
stacked with a short task timer.
By default, metrics are generated with the name, http.server.requests . The name can be customized by setting the
management.metrics.web.server.requests-metric-name property.
By default, Spring MVC-related metrics are tagged with the following information:
Tag

Description

exception

Simple class name of any exception that was thrown while handling the request.

method

Request’s method (for example, GET or POST )

outcome

Request’s outcome based on the status code of the response. 1xx is INFORMATIONAL , 2xx is SUCCESS , 3xx is REDIRECTION ,
4xx CLIENT_ERROR , and 5xx is SERVER_ERROR

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Tag

Description

status

Response’s HTTP status code (for example, 200 or 500 )

uri

Request’s URI template prior to variable substitution, if possible (for example, /api/person/{id} )

To customize the tags, provide a @Bean that implements WebMvcTagsProvider .

57.3.2 Spring WebFlux Metrics
Auto-configuration enables the instrumentation of all requests handled by WebFlux controllers and functional handlers.
By default, metrics are generated with the name http.server.requests . You can customize the name by setting the
management.metrics.web.server.requests-metric-name property.
By default, WebFlux-related metrics are tagged with the following information:
Tag

Description

exception

Simple class name of any exception that was thrown while handling the request.

method

Request’s method (for example, GET or POST )

outcome

Request’s outcome based on the status code of the response. 1xx is INFORMATIONAL , 2xx is SUCCESS , 3xx is REDIRECTION ,
4xx CLIENT_ERROR , and 5xx is SERVER_ERROR

status

Response’s HTTP status code (for example, 200 or 500 )

uri

Request’s URI template prior to variable substitution, if possible (for example, /api/person/{id} )

To customize the tags, provide a @Bean that implements WebFluxTagsProvider .

57.3.3 Jersey Server Metrics
Auto-configuration enables the instrumentation of requests handled by the Jersey JAX-RS implementation. When
management.metrics.web.server.auto-time-requests is true , this instrumentation occurs for all requests. Alternatively, when set to false ,
you can enable instrumentation by adding @Timed to a request-handling method:
@Component
@Path("/api/people")
@Timed
public class Endpoint {
@GET
@Timed(extraTags = { "region", "us-east-1" })
@Timed(value = "all.people", longTask = true)
public List listPeople() { ... }
}

On a resource class to enable timings on every request handler in the resource.
On a method to enable for an individual endpoint. This is not necessary if you have it on the class, but can be used to further customize the
timer for this particular endpoint.
On a method with longTask = true to enable a long task timer for the method. Long task timers require a separate metric name, and can be
stacked with a short task timer.
By default, metrics are generated with the name, http.server.requests . The name can be customized by setting the
management.metrics.web.server.requests-metric-name property.
By default, Jersey server metrics are tagged with the following information:
Tag

Description

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Tag

Description

exception

Simple class name of any exception that was thrown while handling the request.

method

Request’s method (for example, GET or POST )

outcome

Request’s outcome based on the status code of the response. 1xx is INFORMATIONAL , 2xx is SUCCESS , 3xx is REDIRECTION ,
4xx CLIENT_ERROR , and 5xx is SERVER_ERROR

status

Response’s HTTP status code (for example, 200 or 500 )

uri

Request’s URI template prior to variable substitution, if possible (for example, /api/person/{id} )

To customize the tags, provide a @Bean that implements JerseyTagsProvider .

57.3.4 HTTP Client Metrics
Spring Boot Actuator manages the instrumentation of both RestTemplate and WebClient . For that, you have to get injected with an autoconfigured builder and use it to create instances:
RestTemplateBuilder for RestTemplate
WebClient.Builder for WebClient
It is also possible to apply manually the customizers responsible for this instrumentation, namely MetricsRestTemplateCustomizer and
MetricsWebClientCustomizer .
By default, metrics are generated with the name, http.client.requests . The name can be customized by setting the
management.metrics.web.client.requests-metric-name property.
By default, metrics generated by an instrumented client are tagged with the following information:
method , the request’s method (for example, GET or POST ).
uri , the request’s URI template prior to variable substitution, if possible (for example, /api/person/{id} ).
status , the response’s HTTP status code (for example, 200 or 500 ).
clientName , the host portion of the URI.
To customize the tags, and depending on your choice of client, you can provide a @Bean that implements RestTemplateExchangeTagsProvider
or WebClientExchangeTagsProvider . There are convenience static functions in RestTemplateExchangeTags and WebClientExchangeTags .

57.3.5 Cache Metrics
Auto-configuration enables the instrumentation of all available Cache s on startup with metrics prefixed with cache . Cache instrumentation is
standardized for a basic set of metrics. Additional, cache-specific metrics are also available.
The following cache libraries are supported:
Caffeine
EhCache 2
Hazelcast
Any compliant JCache (JSR-107) implementation
Metrics are tagged by the name of the cache and by the name of the CacheManager that is derived from the bean name.

Only caches that are available on startup are bound to the registry. For caches created on-the-fly or programmatically after the startup
phase, an explicit registration is required. A CacheMetricsRegistrar bean is made available to make that process easier.

57.3.6 DataSource Metrics

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Auto-configuration enables the instrumentation of all available DataSource objects with a metric named jdbc . Data source instrumentation results
in gauges representing the currently active, maximum allowed, and minimum allowed connections in the pool. Each of these gauges has a name
that is prefixed by jdbc .
Metrics are also tagged by the name of the DataSource computed based on the bean name.

By default, Spring Boot provides metadata for all supported data sources; you can add additional
DataSourcePoolMetadataProvider beans if your favorite data source isn’t supported out of the box. See
DataSourcePoolMetadataProvidersConfiguration for examples.

Also, Hikari-specific metrics are exposed with a hikaricp prefix. Each metric is tagged by the name of the Pool (can be controlled with
spring.datasource.name ).

57.3.7 Hibernate Metrics
Auto-configuration enables the instrumentation of all available Hibernate EntityManagerFactory instances that have statistics enabled with a
metric named hibernate .
Metrics are also tagged by the name of the EntityManagerFactory that is derived from the bean name.
To enable statistics, the standard JPA property hibernate.generate_statistics must be set to true . You can enable that on the autoconfigured EntityManagerFactory as shown in the following example:
spring.jpa.properties.hibernate.generate_statistics=true

57.3.8 RabbitMQ Metrics
Auto-configuration will enable the instrumentation of all available RabbitMQ connection factories with a metric named rabbitmq .

57.4 Registering custom metrics
To register custom metrics, inject MeterRegistry into your component, as shown in the following example:
class Dictionary {
private final List words = new CopyOnWriteArrayList<>();
Dictionary(MeterRegistry registry) {
registry.gaugeCollectionSize("dictionary.size", Tags.empty(), this.words);
}
// …
}

If you find that you repeatedly instrument a suite of metrics across components or applications, you may encapsulate this suite in a MeterBinder
implementation. By default, metrics from all MeterBinder beans will be automatically bound to the Spring-managed MeterRegistry .

57.5 Customizing individual metrics
If you need to apply customizations to specific Meter instances you can use the io.micrometer.core.instrument.config.MeterFilter
interface. By default, all MeterFilter beans will be automatically applied to the micrometer MeterRegistry.Config .
For example, if you want to rename the mytag.region tag to mytag.area for all meter IDs beginning with com.example , you can do the
following:
@Bean
public MeterFilter renameRegionTagMeterFilter() {
return MeterFilter.renameTag("com.example", "mytag.region", "mytag.area");
}

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57.5.1 Common tags
Common tags are generally used for dimensional drill-down on the operating environment like host, instance, region, stack, etc. Commons tags are
applied to all meters and can be configured as shown in the following example:
management.metrics.tags.region=us-east-1
management.metrics.tags.stack=prod

The example above adds region and stack tags to all meters with a value of us-east-1 and prod respectively.

The order of common tags is important if you are using Graphite. As the order of common tags cannot be guaranteed using this
approach, Graphite users are advised to define a custom MeterFilter instead.

57.5.2 Per-meter properties
In addition to MeterFilter beans, it’s also possible to apply a limited set of customization on a per-meter basis using properties. Per-meter
customizations apply to any all meter IDs that start with the given name. For example, the following will disable any meters that have an ID starting
with example.remote
management.metrics.enable.example.remote=false

The following properties allow per-meter customization:

Table 57.1. Per-meter customizations
Property

Description

management.metrics.enable

Whether to deny meters from emitting any metrics.

management.metrics.distribution.percentiles-histogram

Whether to publish a histogram suitable for computing
aggregable (across dimension) percentile approximations.

management.metrics.distribution.minimum-expected-value ,

Publish less histogram buckets by clamping the range of

management.metrics.distribution.maximum-expected-value

expected values.

management.metrics.distribution.percentiles

Publish percentile values computed in your application

management.metrics.distribution.sla

Publish a cumulative histogram with buckets defined by your
SLAs.

For more details on concepts behind percentiles-histogram , percentiles and sla refer to the "Histograms and percentiles" section of the
micrometer documentation.

57.6 Metrics endpoint
Spring Boot provides a metrics endpoint that can be used diagnostically to examine the metrics collected by an application. The endpoint is not
available by default and must be exposed, see exposing endpoints for more details.
Navigating to /actuator/metrics displays a list of available meter names. You can drill down to view information about a particular meter by
providing its name as a selector, e.g. /actuator/metrics/jvm.memory.max .

The name you use here should match the name used in the code, not the name after it has been naming-convention normalized for a
monitoring system it is shipped to. In other words, if jvm.memory.max appears as jvm_memory_max in Prometheus because of its
snake case naming convention, you should still use jvm.memory.max as the selector when inspecting the meter in the metrics
endpoint.

You can also add any number of tag=KEY:VALUE query parameters to the end of the URL to dimensionally drill down on a meter, e.g.
/actuator/metrics/jvm.memory.max?tag=area:nonheap .
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The reported measurements are the sum of the statistics of all meters matching the meter name and any tags that have been applied.
So in the example above, the returned "Value" statistic is the sum of the maximum memory footprints of "Code Cache", "Compressed
Class Space", and "Metaspace" areas of the heap. If you just wanted to see the maximum size for the "Metaspace", you could add an
additional tag=id:Metaspace , i.e. /actuator/metrics/jvm.memory.max?tag=area:nonheap&tag=id:Metaspace .

58. Auditing
Once Spring Security is in play, Spring Boot Actuator has a flexible audit framework that publishes events (by default, “authentication success”,
“failure” and “access denied” exceptions). This feature can be very useful for reporting and for implementing a lock-out policy based on
authentication failures. To customize published security events, you can provide your own implementations of
AbstractAuthenticationAuditListener and AbstractAuthorizationAuditListener .
You can also use the audit services for your own business events. To do so, either inject the existing AuditEventRepository into your own
components and use that directly or publish an AuditApplicationEvent with the Spring ApplicationEventPublisher (by implementing
ApplicationEventPublisherAware ).

59. HTTP Tracing
Tracing is automatically enabled for all HTTP requests. You can view the httptrace endpoint and obtain basic information about the last 100
request-response exchanges.

59.1 Custom HTTP tracing
To customize the items that are included in each trace, use the management.trace.http.include configuration property. For advanced
customization, consider registering your own HttpExchangeTracer implementation.
By default, an InMemoryHttpTraceRepository that stores traces for the last 100 request-response exchanges is used. If you need to expand the
capacity, you can define your own instance of the InMemoryHttpTraceRepository bean. You can also create your own alternative
HttpTraceRepository implementation.

60. Process Monitoring
In the spring-boot module, you can find two classes to create files that are often useful for process monitoring:
ApplicationPidFileWriter creates a file containing the application PID (by default, in the application directory with a file name of
application.pid ).
WebServerPortFileWriter creates a file (or files) containing the ports of the running web server (by default, in the application directory with a
file name of application.port ).
By default, these writers are not activated, but you can enable:
By Extending Configuration
Section 60.2, “Programmatically”

60.1 Extending Configuration
In the META-INF/spring.factories file, you can activate the listener(s) that writes a PID file, as shown in the following example:
org.springframework.context.ApplicationListener=\
org.springframework.boot.context.ApplicationPidFileWriter,\
org.springframework.boot.web.context.WebServerPortFileWriter

60.2 Programmatically
You can also activate a listener by invoking the SpringApplication.addListeners(…) method and passing the appropriate Writer object. This
method also lets you customize the file name and path in the Writer constructor.
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61. Cloud Foundry Support
Spring Boot’s actuator module includes additional support that is activated when you deploy to a compatible Cloud Foundry instance. The
/cloudfoundryapplication path provides an alternative secured route to all @Endpoint beans.
The extended support lets Cloud Foundry management UIs (such as the web application that you can use to view deployed applications) be
augmented with Spring Boot actuator information. For example, an application status page may include full health information instead of the typical
“running” or “stopped” status.

The /cloudfoundryapplication path is not directly accessible to regular users. In order to use the endpoint, a valid UAA token
must be passed with the request.

61.1 Disabling Extended Cloud Foundry Actuator Support
If you want to fully disable the /cloudfoundryapplication endpoints, you can add the following setting to your application.properties file:
application.properties.
management.cloudfoundry.enabled=false

61.2 Cloud Foundry Self-signed Certificates
By default, the security verification for /cloudfoundryapplication endpoints makes SSL calls to various Cloud Foundry services. If your Cloud
Foundry UAA or Cloud Controller services use self-signed certificates, you need to set the following property:
application.properties.
management.cloudfoundry.skip-ssl-validation=true

61.3 Custom context path
If the server’s context-path has been configured to anything other than / , the Cloud Foundry endpoints will not be available at the root of the
application. For example, if server.servlet.context-path=/app , Cloud Foundry endpoints will be available at
/app/cloudfoundryapplication/* .
If you expect the Cloud Foundry endpoints to always be available at /cloudfoundryapplication/* , regardless of the server’s context-path, you
will need to explicitly configure that in your application. The configuration will differ depending on the web server in use. For Tomcat, the following
configuration can be added:
@Bean
public TomcatServletWebServerFactory servletWebServerFactory() {
return new TomcatServletWebServerFactory() {
@Override
protected void prepareContext(Host host,
ServletContextInitializer[] initializers) {
super.prepareContext(host, initializers);
StandardContext child = new StandardContext();
child.addLifecycleListener(new Tomcat.FixContextListener());
child.setPath("/cloudfoundryapplication");
ServletContainerInitializer initializer = getServletContextInitializer(
getContextPath());
child.addServletContainerInitializer(initializer, Collections.emptySet());
child.setCrossContext(true);
host.addChild(child);
}
};
}
private ServletContainerInitializer getServletContextInitializer(String contextPath) {

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(

g

)

return (c, context) -> {
Servlet servlet = new GenericServlet() {
@Override
public void service(ServletRequest req, ServletResponse res)
throws ServletException, IOException {
ServletContext context = req.getServletContext()
.getContext(contextPath);
context.getRequestDispatcher("/cloudfoundryapplication").forward(req,
res);
}
};
context.addServlet("cloudfoundry", servlet).addMapping("/*");
};
}

62. What to Read Next
If you want to explore some of the concepts discussed in this chapter, you can take a look at the actuator sample applications. You also might want
to read about graphing tools such as Graphite.
Otherwise, you can continue on, to read about ‘deployment options’ or jump ahead for some in-depth information about Spring Boot’s build tool
plugins.

Part VI. Deploying Spring Boot Applications
Spring Boot’s flexible packaging options provide a great deal of choice when it comes to deploying your application. You can deploy Spring Boot
applications to a variety of cloud platforms, to container images (such as Docker), or to virtual/real machines.
This section covers some of the more common deployment scenarios.

63. Deploying to the Cloud
Spring Boot’s executable jars are ready-made for most popular cloud PaaS (Platform-as-a-Service) providers. These providers tend to require that
you “bring your own container”. They manage application processes (not Java applications specifically), so they need an intermediary layer that
adapts your application to the cloud’s notion of a running process.
Two popular cloud providers, Heroku and Cloud Foundry, employ a “buildpack” approach. The buildpack wraps your deployed code in whatever is
needed to start your application. It might be a JDK and a call to java , an embedded web server, or a full-fledged application server. A buildpack is
pluggable, but ideally you should be able to get by with as few customizations to it as possible. This reduces the footprint of functionality that is not
under your control. It minimizes divergence between development and production environments.
Ideally, your application, like a Spring Boot executable jar, has everything that it needs to run packaged within it.
In this section, we look at what it takes to get the simple application that we developed in the “Getting Started” section up and running in the Cloud.

63.1 Cloud Foundry
Cloud Foundry provides default buildpacks that come into play if no other buildpack is specified. The Cloud Foundry Java buildpack has excellent
support for Spring applications, including Spring Boot. You can deploy stand-alone executable jar applications as well as traditional .war packaged
applications.
Once you have built your application (by using, for example, mvn clean package ) and have installed the cf command line tool, deploy your
application by using the cf push command, substituting the path to your compiled .jar . Be sure to have logged in with your cf command line
client before pushing an application. The following line shows using the cf push command to deploy an application:
$ cf push acloudyspringtime -p target/demo-0.0.1-SNAPSHOT.jar

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In the preceding example, we substitute acloudyspringtime for whatever value you give cf as the name of your application.

See the cf push documentation for more options. If there is a Cloud Foundry manifest.yml file present in the same directory, it is considered.
At this point, cf starts uploading your application, producing output similar to the following example:
Uploading acloudyspringtime... OK
Preparing to start acloudyspringtime... OK
-----> Downloaded app package (8.9M)
-----> Java Buildpack Version: v3.12 (offline) | https://github.com/cloudfoundry/java-buildpack.git#6f25b7e
-----> Downloading Open Jdk JRE 1.8.0_121 from https://java-buildpack.cloudfoundry.org/openjdk/trusty/x86_64/openjdk-1.8.0_121
Expanding Open Jdk JRE to .java-buildpack/open_jdk_jre (1.6s)
-----> Downloading Open JDK Like Memory Calculator 2.0.2_RELEASE from https://java-buildpack.cloudfoundry.org/memory-calculato
Memory Settings: -Xss349K -Xmx681574K -XX:MaxMetaspaceSize=104857K -Xms681574K -XX:MetaspaceSize=104857K
-----> Downloading Container Certificate Trust Store 1.0.0_RELEASE from https://java-buildpack.cloudfoundry.org/container-cert
Adding certificates to .java-buildpack/container_certificate_trust_store/truststore.jks (0.6s)
-----> Downloading Spring Auto Reconfiguration 1.10.0_RELEASE from https://java-buildpack.cloudfoundry.org/auto-reconfiguratio
Checking status of app 'acloudyspringtime'...
0 of 1 instances running (1 starting)
...
0 of 1 instances running (1 starting)
...
0 of 1 instances running (1 starting)
...
1 of 1 instances running (1 running)
App started

Congratulations! The application is now live!
Once your application is live, you can verify the status of the deployed application by using the cf apps command, as shown in the following
example:
$ cf apps
Getting applications in ...
OK
name
...
acloudyspringtime
...

requested state

instances

memory

disk

urls

started

1/1

512M

1G

acloudyspringtime.cfapps.io

Once Cloud Foundry acknowledges that your application has been deployed, you should be able to find the application at the URI given. In the
preceding example, you could find it at http://acloudyspringtime.cfapps.io/ .

63.1.1 Binding to Services
By default, metadata about the running application as well as service connection information is exposed to the application as environment variables
(for example: $VCAP_SERVICES ). This architecture decision is due to Cloud Foundry’s polyglot (any language and platform can be supported as a
buildpack) nature. Process-scoped environment variables are language agnostic.
Environment variables do not always make for the easiest API, so Spring Boot automatically extracts them and flattens the data into properties that
can be accessed through Spring’s Environment abstraction, as shown in the following example:

@Component
class MyBean implements EnvironmentAware {
private String instanceId;
@Override
public void setEnvironment(Environment environment) {
this.instanceId = environment.getProperty("vcap.application.instance_id");
}

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// ...

}

All Cloud Foundry properties are prefixed with vcap . You can use vcap properties to access application information (such as the public URL of the
application) and service information (such as database credentials). See the ‘CloudFoundryVcapEnvironmentPostProcessor’ Javadoc for complete
details.

The Spring Cloud Connectors project is a better fit for tasks such as configuring a DataSource. Spring Boot includes autoconfiguration support and a spring-boot-starter-cloud-connectors starter.

63.2 Heroku
Heroku is another popular PaaS platform. To customize Heroku builds, you provide a Procfile , which provides the incantation required to deploy
an application. Heroku assigns a port for the Java application to use and then ensures that routing to the external URI works.
You must configure your application to listen on the correct port. The following example shows the Procfile for our starter REST application:
web: java -Dserver.port=$PORT -jar target/demo-0.0.1-SNAPSHOT.jar

Spring Boot makes -D arguments available as properties accessible from a Spring Environment instance. The server.port configuration
property is fed to the embedded Tomcat, Jetty, or Undertow instance, which then uses the port when it starts up. The $PORT environment variable is
assigned to us by the Heroku PaaS.
This should be everything you need. The most common deployment workflow for Heroku deployments is to git push the code to production, as
shown in the following example:
$ git push heroku master
Initializing repository, done.
Counting objects: 95, done.
Delta compression using up to 8 threads.
Compressing objects: 100% (78/78), done.
Writing objects: 100% (95/95), 8.66 MiB | 606.00 KiB/s, done.
Total 95 (delta 31), reused 0 (delta 0)
----->
----->
----->
----->
----->

Java app detected
Installing OpenJDK 1.8... done
Installing Maven 3.3.1... done
Installing settings.xml... done
Executing: mvn -B -DskipTests=true clean install
[INFO] Scanning for projects...
Downloading: https://repo.spring.io/...
Downloaded: https://repo.spring.io/... (818 B at 1.8 KB/sec)
....
Downloaded: http://s3pository.heroku.com/jvm/... (152 KB at 595.3 KB/sec)
[INFO]
[INFO]
[INFO]
[INFO]
[INFO]
[INFO]
[INFO]
[INFO]
[INFO]

Installing /tmp/build_0c35a5d2-a067-4abc-a232-14b1fb7a8229/target/...
Installing /tmp/build_0c35a5d2-a067-4abc-a232-14b1fb7a8229/pom.xml ...
-----------------------------------------------------------------------BUILD SUCCESS
-----------------------------------------------------------------------Total time: 59.358s
Finished at: Fri Mar 07 07:28:25 UTC 2014
Final Memory: 20M/493M
------------------------------------------------------------------------

-----> Discovering process types
Procfile declares types -> web
-----> Compressing... done, 70.4MB
-----> Launching... done, v6
http://agile-sierra-1405.herokuapp.com/ deployed to Heroku

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To git@heroku.com:agile-sierra-1405.git
* [new branch]
master -> master

Your application should now be up and running on Heroku.

63.3 OpenShift
OpenShift is the Red Hat public (and enterprise) extension of the Kubernetes container orchestration platform. Similarly to Kubernetes, OpenShift
has many options for installing Spring Boot based applications.
OpenShift has many resources describing how to deploy Spring Boot applications, including:
Using the S2I builder
Architecture guide
Running as a traditional web application on Wildfly
OpenShift Commons Briefing

63.4 Amazon Web Services (AWS)
Amazon Web Services offers multiple ways to install Spring Boot-based applications, either as traditional web applications (war) or as executable jar
files with an embedded web server. The options include:
AWS Elastic Beanstalk
AWS Code Deploy
AWS OPS Works
AWS Cloud Formation
AWS Container Registry
Each has different features and pricing models. In this document, we describe only the simplest option: AWS Elastic Beanstalk.

63.4.1 AWS Elastic Beanstalk
As described in the official Elastic Beanstalk Java guide, there are two main options to deploy a Java application. You can either use the “Tomcat
Platform” or the “Java SE platform”.

Using the Tomcat Platform
This option applies to Spring Boot projects that produce a war file. No special configuration is required. You need only follow the official guide.

Using the Java SE Platform
This option applies to Spring Boot projects that produce a jar file and run an embedded web container. Elastic Beanstalk environments run an nginx
instance on port 80 to proxy the actual application, running on port 5000. To configure it, add the following line to your application.properties
file:
server.port=5000

By default, Elastic Beanstalk uploads sources and compiles them in AWS. However, it is best to upload the binaries instead. To do so,
add lines similar to the following to your .elasticbeanstalk/config.yml file:
deploy:
artifact: target/demo-0.0.1-SNAPSHOT.jar

By default an Elastic Beanstalk environment is load balanced. The load balancer has a significant cost. To avoid that cost, set the
environment type to “Single instance”, as described in the Amazon documentation. You can also create single instance environments
by using the CLI and the following command:
eb create -s

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63.4.2 Summary
This is one of the easiest ways to get to AWS, but there are more things to cover, such as how to integrate Elastic Beanstalk into any CI / CD tool,
use the Elastic Beanstalk Maven plugin instead of the CLI, and others. There is a blog post covering these topics more in detail.

63.5 Boxfuse and Amazon Web Services
Boxfuse works by turning your Spring Boot executable jar or war into a minimal VM image that can be deployed unchanged either on VirtualBox or
on AWS. Boxfuse comes with deep integration for Spring Boot and uses the information from your Spring Boot configuration file to automatically
configure ports and health check URLs. Boxfuse leverages this information both for the images it produces as well as for all the resources it
provisions (instances, security groups, elastic load balancers, and so on).
Once you have created a Boxfuse account, connected it to your AWS account, installed the latest version of the Boxfuse Client, and ensured that
the application has been built by Maven or Gradle (by using, for example, mvn clean package ), you can deploy your Spring Boot application to
AWS with a command similar to the following:
$ boxfuse run myapp-1.0.jar -env=prod

See the boxfuse run documentation for more options. If there is a boxfuse.conf file present in the current directory, it is considered.

By default, Boxfuse activates a Spring profile named boxfuse on startup. If your executable jar or war contains an
application-boxfuse.properties file, Boxfuse bases its configuration on the properties it contains.

At this point, boxfuse creates an image for your application, uploads it, and configures and starts the necessary resources on AWS, resulting in
output similar to the following example:
Fusing Image for myapp-1.0.jar ...
Image fused in 00:06.838s (53937 K) -> axelfontaine/myapp:1.0
Creating axelfontaine/myapp ...
Pushing axelfontaine/myapp:1.0 ...
Verifying axelfontaine/myapp:1.0 ...
Creating Elastic IP ...
Mapping myapp-axelfontaine.boxfuse.io to 52.28.233.167 ...
Waiting for AWS to create an AMI for axelfontaine/myapp:1.0 in eu-central-1 (this may take up to 50 seconds) ...
AMI created in 00:23.557s -> ami-d23f38cf
Creating security group boxfuse-sg_axelfontaine/myapp:1.0 ...
Launching t2.micro instance of axelfontaine/myapp:1.0 (ami-d23f38cf) in eu-central-1 ...
Instance launched in 00:30.306s -> i-92ef9f53
Waiting for AWS to boot Instance i-92ef9f53 and Payload to start at http://52.28.235.61/ ...
Payload started in 00:29.266s -> http://52.28.235.61/
Remapping Elastic IP 52.28.233.167 to i-92ef9f53 ...
Waiting 15s for AWS to complete Elastic IP Zero Downtime transition ...
Deployment completed successfully. axelfontaine/myapp:1.0 is up and running at http://myapp-axelfontaine.boxfuse.io/

Your application should now be up and running on AWS.
See the blog post on deploying Spring Boot apps on EC2 as well as the documentation for the Boxfuse Spring Boot integration to get started with a
Maven build to run the app.

63.6 Google Cloud
Google Cloud has several options that can be used to launch Spring Boot applications. The easiest to get started with is probably App Engine, but
you could also find ways to run Spring Boot in a container with Container Engine or on a virtual machine with Compute Engine.
To run in App Engine, you can create a project in the UI first, which sets up a unique identifier for you and also sets up HTTP routes. Add a Java app
to the project and leave it empty and then use the Google Cloud SDK to push your Spring Boot app into that slot from the command line or CI build.
App Engine Standard requires you to use WAR packaging. Follow these steps to deploy App Engine Standard application to Google Cloud.
Alternatively, App Engine Flex requires you to create an app.yaml file to describe the resources your app requires. Normally, you put this file in
src/main/appengine , and it should resemble the following file:

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service: default
runtime: java
env: flex
runtime_config:
jdk: openjdk8
handlers:
- url: /.*
script: this field is required, but ignored
manual_scaling:
instances: 1
health_check:
enable_health_check: False
env_variables:
ENCRYPT_KEY: your_encryption_key_here

You can deploy the app (for example, with a Maven plugin) by adding the project ID to the build configuration, as shown in the following example:

com.google.cloud.tools
appengine-maven-plugin
1.3.0

myproject



Then deploy with mvn appengine:deploy (if you need to authenticate first, the build fails).

64. Installing Spring Boot Applications
In addition to running Spring Boot applications by using java -jar , it is also possible to make fully executable applications for Unix systems. A
fully executable jar can be executed like any other executable binary or it can be registered with init.d or systemd . This makes it very easy to
install and manage Spring Boot applications in common production environments.
Caution
Fully executable jars work by embedding an extra script at the front of the file. Currently, some tools do not accept this
format, so you may not always be able to use this technique. For example, jar -xf may silently fail to extract a jar or war
that has been made fully executable. It is recommended that you make your jar or war fully executable only if you intend to
execute it directly, rather than running it with java -jar or deploying it to a servlet container.

To create a ‘fully executable’ jar with Maven, use the following plugin configuration:

org.springframework.boot
spring-boot-maven-plugin

true



The following example shows the equivalent Gradle configuration:
bootJar {
launchScript()
}

You can then run your application by typing ./my-application.jar (where my-application is the name of your artifact). The directory
containing the jar is used as your application’s working directory.
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64.1 Supported Operating Systems
The default script supports most Linux distributions and is tested on CentOS and Ubuntu. Other platforms, such as OS X and FreeBSD, require the
use of a custom embeddedLaunchScript .

64.2 Unix/Linux Services
Spring Boot application can be easily started as Unix/Linux services by using either init.d or systemd .

64.2.1 Installation as an init.d Service (System V)
If you configured Spring Boot’s Maven or Gradle plugin to generate a fully executable jar, and you do not use a custom embeddedLaunchScript ,
your application can be used as an init.d service. To do so, symlink the jar to init.d to support the standard start , stop , restart , and
status commands.
The script supports the following features:
Starts the services as the user that owns the jar file
Tracks the application’s PID by using /var/run//.pid
Writes console logs to /var/log/.log
Assuming that you have a Spring Boot application installed in /var/myapp , to install a Spring Boot application as an init.d service, create a
symlink, as follows:
$ sudo ln -s /var/myapp/myapp.jar /etc/init.d/myapp

Once installed, you can start and stop the service in the usual way. For example, on a Debian-based system, you could start it with the following
command:
$ service myapp start

If your application fails to start, check the log file written to /var/log/.log for errors.

You can also flag the application to start automatically by using your standard operating system tools. For example, on Debian, you could use the
following command:
$ update-rc.d myapp defaults 

Securing an init.d Service
The following is a set of guidelines on how to secure a Spring Boot application that runs as an init.d service. It is not intended to be an
exhaustive list of everything that should be done to harden an application and the environment in which it runs.

When executed as root, as is the case when root is being used to start an init.d service, the default executable script runs the application as the user
who owns the jar file. You should never run a Spring Boot application as root , so your application’s jar file should never be owned by root. Instead,
create a specific user to run your application and use chown to make it the owner of the jar file, as shown in the following example:
$ chown bootapp:bootapp your-app.jar

In this case, the default executable script runs the application as the bootapp user.

To reduce the chances of the application’s user account being compromised, you should consider preventing it from using a login
shell. For example, you can set the account’s shell to /usr/sbin/nologin .

You should also take steps to prevent the modification of your application’s jar file. Firstly, configure its permissions so that it cannot be written and
can only be read or executed by its owner, as shown in the following example:
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$ chmod 500 your-app.jar

Second, you should also take steps to limit the damage if your application or the account that’s running it is compromised. If an attacker does gain
access, they could make the jar file writable and change its contents. One way to protect against this is to make it immutable by using chattr , as
shown in the following example:
$ sudo chattr +i your-app.jar

This will prevent any user, including root, from modifying the jar.
If root is used to control the application’s service and you use a .conf file to customize its startup, the .conf file is read and evaluated by the root
user. It should be secured accordingly. Use chmod so that the file can only be read by the owner and use chown to make root the owner, as shown
in the following example:
$ chmod 400 your-app.conf
$ sudo chown root:root your-app.conf

64.2.2 Installation as a systemd Service
systemd is the successor of the System V init system and is now being used by many modern Linux distributions. Although you can continue to
use init.d scripts with systemd , it is also possible to launch Spring Boot applications by using systemd ‘service’ scripts.
Assuming that you have a Spring Boot application installed in /var/myapp , to install a Spring Boot application as a systemd service, create a
script named myapp.service and place it in /etc/systemd/system directory. The following script offers an example:
[Unit]
Description=myapp
After=syslog.target
[Service]
User=myapp
ExecStart=/var/myapp/myapp.jar
SuccessExitStatus=143
[Install]
WantedBy=multi-user.target

Important
Remember to change the Description , User , and ExecStart fields for your application.

The ExecStart field does not declare the script action command, which means that the run command is used by default.

Note that, unlike when running as an init.d service, the user that runs the application, the PID file, and the console log file are managed by
systemd itself and therefore must be configured by using appropriate fields in the ‘service’ script. Consult the service unit configuration man page
for more details.
To flag the application to start automatically on system boot, use the following command:
$ systemctl enable myapp.service

Refer to man systemctl for more details.

64.2.3 Customizing the Startup Script
The default embedded startup script written by the Maven or Gradle plugin can be customized in a number of ways. For most people, using the
default script along with a few customizations is usually enough. If you find you cannot customize something that you need to, use the
embeddedLaunchScript option to write your own file entirely.

Customizing the Start Script when It Is Written
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It often makes sense to customize elements of the start script as it is written into the jar file. For example, init.d scripts can provide a “description”.
Since you know the description up front (and it need not change), you may as well provide it when the jar is generated.
To customize written elements, use the embeddedLaunchScriptProperties option of the Spring Boot Maven plugin or the properties property
of the Spring Boot Gradle plugin’s launchScript .
The following property substitutions are supported with the default script:
Name

Description

Gradle default

Maven default

mode

The script mode.

auto

auto

initInfoProvides

The Provides section of “INIT

${task.baseName}

${project.artifactId}

$remote_fs $syslog $network

$remote_fs $syslog $network

$remote_fs $syslog $network

$remote_fs $syslog $network

2 3 4 5

2 3 4 5

0 1 6

0 1 6

Short-Description section of

Single-line version of

${project.name}

“INIT INFO”.

${project.description}

INFO”
initInfoRequiredStart

Required-Start section of
“INIT INFO”.

initInfoRequiredStop

Required-Stop section of
“INIT INFO”.

initInfoDefaultStart

Default-Start section of
“INIT INFO”.

initInfoDefaultStop

Default-Stop section of “INIT
INFO”.

initInfoShortDescription

(falling back to
${task.baseName} )
initInfoDescription

initInfoChkconfig

Description section of “INIT

${project.description}

${project.description}

INFO”.

(falling back to

(falling back to

${task.baseName} )

${project.name} )

2345 99 01

2345 99 01

Folder containing the jar

Folder containing the jar

chkconfig section of “INIT
INFO”

confFolder

The default value for
CONF_FOLDER

inlinedConfScript

Reference to a file script that
should be inlined in the default
launch script. This can be used
to set environmental variables
such as JAVA_OPTS before any
external config files are loaded

logFolder

Default value for LOG_FOLDER .
Only valid for an init.d
service

logFilename

Default value for
LOG_FILENAME . Only valid for
an init.d service

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Name

Description

pidFolder

Default value for PID_FOLDER .

Gradle default

Maven default

true

true

60

60

Only valid for an init.d
service
pidFilename

Default value for the name of
the PID file in PID_FOLDER .
Only valid for an init.d
service

useStartStopDaemon

Whether the
start-stop-daemon
command, when it’s available,
should be used to control the
process

stopWaitTime

Default value for
STOP_WAIT_TIME in seconds.
Only valid for an init.d
service

Customizing a Script When It Runs
For items of the script that need to be customized after the jar has been written, you can use environment variables or a config file.
The following environment properties are supported with the default script:
Variable

Description

MODE

The “mode” of operation. The default depends on the way the jar was built but is usually auto (meaning it tries
to guess if it is an init script by checking if it is a symlink in a directory called init.d ). You can explicitly set it to
service so that the stop|start|status|restart commands work or to run if you want to run the script in
the foreground.

USE_START_STOP_DAEMON

Whether the start-stop-daemon command, when it’s available, should be used to control the process.
Defaults to true .

PID_FOLDER

The root name of the pid folder ( /var/run by default).

LOG_FOLDER

The name of the folder in which to put log files ( /var/log by default).

CONF_FOLDER

The name of the folder from which to read .conf files (same folder as jar-file by default).

LOG_FILENAME

The name of the log file in the LOG_FOLDER ( .log by default).

APP_NAME

The name of the app. If the jar is run from a symlink, the script guesses the app name. If it is not a symlink or you
want to explicitly set the app name, this can be useful.

RUN_ARGS

The arguments to pass to the program (the Spring Boot app).

JAVA_HOME

The location of the java executable is discovered by using the PATH by default, but you can set it explicitly if
there is an executable file at $JAVA_HOME/bin/java .

JAVA_OPTS

Options that are passed to the JVM when it is launched.

JARFILE

The explicit location of the jar file, in case the script is being used to launch a jar that it is not actually embedded.

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Variable

Description

DEBUG

If not empty, sets the -x flag on the shell process, making it easy to see the logic in the script.

STOP_WAIT_TIME

The time in seconds to wait when stopping the application before forcing a shutdown ( 60 by default).

The PID_FOLDER , LOG_FOLDER , and LOG_FILENAME variables are only valid for an init.d service. For systemd , the equivalent
customizations are made by using the ‘service’ script. See the service unit configuration man page for more details.

With the exception of JARFILE and APP_NAME , the settings listed in the preceding section can be configured by using a .conf file. The file is
expected to be next to the jar file and have the same name but suffixed with .conf rather than .jar . For example, a jar named
/var/myapp/myapp.jar uses the configuration file named /var/myapp/myapp.conf , as shown in the following example:
myapp.conf.
JAVA_OPTS=-Xmx1024M
LOG_FOLDER=/custom/log/folder

If you do not like having the config file next to the jar file, you can set a CONF_FOLDER environment variable to customize the location
of the config file.

To learn about securing this file appropriately, see the guidelines for securing an init.d service.

64.3 Microsoft Windows Services
A Spring Boot application can be started as a Windows service by using winsw .
A (separately maintained sample) describes step-by-step how you can create a Windows service for your Spring Boot application.

65. What to Read Next
Check out the Cloud Foundry, Heroku, OpenShift, and Boxfuse web sites for more information about the kinds of features that a PaaS can offer.
These are just four of the most popular Java PaaS providers. Since Spring Boot is so amenable to cloud-based deployment, you can freely consider
other providers as well.
The next section goes on to cover the Spring Boot CLI, or you can jump ahead to read about build tool plugins.

Part VII. Spring Boot CLI
The Spring Boot CLI is a command line tool that you can use if you want to quickly develop a Spring application. It lets you run Groovy scripts, which
means that you have a familiar Java-like syntax without so much boilerplate code. You can also bootstrap a new project or write your own command
for it.

66. Installing the CLI
The Spring Boot CLI (Command-Line Interface) can be installed manually by using SDKMAN! (the SDK Manager) or by using Homebrew or
MacPorts if you are an OSX user. See Section 10.2, “Installing the Spring Boot CLI” in the “Getting started” section for comprehensive installation
instructions.

67. Using the CLI
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Once you have installed the CLI, you can run it by typing spring and pressing Enter at the command line. If you run spring without any
arguments, a simple help screen is displayed, as follows:
$ spring
usage: spring [--help] [--version]
 []
Available commands are:
run [options]  [--] [args]
Run a spring groovy script
... more command help is shown here

You can type spring help to get more details about any of the supported commands, as shown in the following example:
$ spring help run
spring run - Run a spring groovy script
usage: spring run [options]  [--] [args]
Option
-------autoconfigure [Boolean]
--classpath, -cp
-e, --edit
--no-guess-dependencies
--no-guess-imports
-q, --quiet
-v, --verbose
--watch

Description
----------Add autoconfigure compiler
transformations (default: true)
Additional classpath entries
Open the file with the default system
editor
Do not attempt to guess dependencies
Do not attempt to guess imports
Quiet logging
Verbose logging of dependency
resolution
Watch the specified file for changes

The version command provides a quick way to check which version of Spring Boot you are using, as follows:
$ spring version
Spring CLI v2.1.2.BUILD-SNAPSHOT

67.1 Running Applications with the CLI
You can compile and run Groovy source code by using the run command. The Spring Boot CLI is completely self-contained, so you do not need
any external Groovy installation.
The following example shows a “hello world” web application written in Groovy:
hello.groovy.
@RestController
class WebApplication {
@RequestMapping("/")
String home() {
"Hello World!"
}
}

To compile and run the application, type the following command:
$ spring run hello.groovy

To pass command-line arguments to the application, use -- to separate the commands from the “spring” command arguments, as shown in the
following example:

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$ spring run hello.groovy -- --server.port=9000

To set JVM command line arguments, you can use the JAVA_OPTS environment variable, as shown in the following example:
$ JAVA_OPTS=-Xmx1024m spring run hello.groovy

When setting JAVA_OPTS on Microsoft Windows, make sure to quote the entire instruction, such as
set "JAVA_OPTS=-Xms256m -Xmx2048m" . Doing so ensures the values are properly passed to the process.

67.1.1 Deduced “grab” Dependencies
Standard Groovy includes a @Grab annotation, which lets you declare dependencies on third-party libraries. This useful technique lets Groovy
download jars in the same way as Maven or Gradle would but without requiring you to use a build tool.
Spring Boot extends this technique further and tries to deduce which libraries to “grab” based on your code. For example, since the
WebApplication code shown previously uses @RestController annotations, Spring Boot grabs "Tomcat" and "Spring MVC".
The following items are used as “grab hints”:
Items

Grabs

JdbcTemplate , NamedParameterJdbcTemplate , DataSource

JDBC Application.

@EnableJms

JMS Application.

@EnableCaching

Caching abstraction.

@Test

JUnit.

@EnableRabbit

RabbitMQ.

extends Specification

Spock test.

@EnableBatchProcessing

Spring Batch.

@MessageEndpoint @EnableIntegration

Spring Integration.

@Controller @RestController @EnableWebMvc

Spring MVC + Embedded Tomcat.

@EnableWebSecurity

Spring Security.

@EnableTransactionManagement

Spring Transaction Management.

See subclasses of CompilerAutoConfiguration in the Spring Boot CLI source code to understand exactly how customizations are
applied.

67.1.2 Deduced “grab” Coordinates
Spring Boot extends Groovy’s standard @Grab support by letting you specify a dependency without a group or version (for example,
@Grab('freemarker') ). Doing so consults Spring Boot’s default dependency metadata to deduce the artifact’s group and version.

The default metadata is tied to the version of the CLI that you use. it changes only when you move to a new version of the CLI, putting
you in control of when the versions of your dependencies may change. A table showing the dependencies and their versions that are
included in the default metadata can be found in the appendix.

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67.1.3 Default Import Statements
To help reduce the size of your Groovy code, several import statements are automatically included. Notice how the preceding example refers to
@Component , @RestController , and @RequestMapping without needing to use fully-qualified names or import statements.

Many Spring annotations work without using import statements. Try running your application to see what fails before adding imports.

67.1.4 Automatic Main Method
Unlike the equivalent Java application, you do not need to include a public static void main(String[] args) method with your Groovy
scripts. A SpringApplication is automatically created, with your compiled code acting as the source .

67.1.5 Custom Dependency Management
By default, the CLI uses the dependency management declared in spring-boot-dependencies when resolving @Grab dependencies. Additional
dependency management, which overrides the default dependency management, can be configured by using the @DependencyManagementBom
annotation. The annotation’s value should specify the coordinates ( groupId:artifactId:version ) of one or more Maven BOMs.
For example, consider the following declaration:
@DependencyManagementBom("com.example.custom-bom:1.0.0")

The preceding declaration picks up custom-bom-1.0.0.pom in a Maven repository under com/example/custom-versions/1.0.0/ .
When you specify multiple BOMs, they are applied in the order in which you declare them, as shown in the following example:
@DependencyManagementBom(["com.example.custom-bom:1.0.0",
"com.example.another-bom:1.0.0"])

The preceding example indicates that the dependency management in another-bom overrides the dependency management in custom-bom .
You can use @DependencyManagementBom anywhere that you can use @Grab . However, to ensure consistent ordering of the dependency
management, you can use @DependencyManagementBom at most once in your application. A useful source of dependency management (which is a
superset of Spring Boot’s dependency management) is the Spring IO Platform, which you might include with the following line:
@DependencyManagementBom('io.spring.platform:platform-bom:1.1.2.RELEASE')

67.2 Applications with Multiple Source Files
You can use “shell globbing” with all commands that accept file input. Doing so lets you use multiple files from a single directory, as shown in the
following example:
$ spring run *.groovy

67.3 Packaging Your Application
You can use the jar command to package your application into a self-contained executable jar file, as shown in the following example:
$ spring jar my-app.jar *.groovy

The resulting jar contains the classes produced by compiling the application and all of the application’s dependencies so that it can then be run by
using java -jar . The jar file also contains entries from the application’s classpath. You can add and remove explicit paths to the jar by using
--include and --exclude . Both are comma-separated, and both accept prefixes, in the form of “+” and “-”, to signify that they should be
removed from the defaults. The default includes are as follows:
public/**, resources/**, static/**, templates/**, META-INF/**, *

The default excludes are as follows:

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.*, repository/**, build/**, target/**, **/*.jar, **/*.groovy

Type spring help jar on the command line for more information.

67.4 Initialize a New Project
The init command lets you create a new project by using start.spring.io without leaving the shell, as shown in the following example:
$ spring init --dependencies=web,data-jpa my-project
Using service at https://start.spring.io
Project extracted to '/Users/developer/example/my-project'

The preceding example creates a my-project directory with a Maven-based project that uses spring-boot-starter-web and
spring-boot-starter-data-jpa . You can list the capabilities of the service by using the --list flag, as shown in the following example:
$ spring init --list
=======================================
Capabilities of https://start.spring.io
=======================================
Available dependencies:
----------------------actuator - Actuator: Production ready features to help you monitor and manage your application
...
web - Web: Support for full-stack web development, including Tomcat and spring-webmvc
websocket - Websocket: Support for WebSocket development
ws - WS: Support for Spring Web Services
Available project types:
-----------------------gradle-build - Gradle Config [format:build, build:gradle]
gradle-project - Gradle Project [format:project, build:gradle]
maven-build - Maven POM [format:build, build:maven]
maven-project - Maven Project [format:project, build:maven] (default)
...

The init command supports many options. See the help output for more details. For instance, the following command creates a Gradle project
that uses Java 8 and war packaging:
$ spring init --build=gradle --java-version=1.8 --dependencies=websocket --packaging=war sample-app.zip
Using service at https://start.spring.io
Content saved to 'sample-app.zip'

67.5 Using the Embedded Shell
Spring Boot includes command-line completion scripts for the BASH and zsh shells. If you do not use either of these shells (perhaps you are a
Windows user), you can use the shell command to launch an integrated shell, as shown in the following example:
$ spring shell
Spring Boot (v2.1.2.BUILD-SNAPSHOT)
Hit TAB to complete. Type \'help' and hit RETURN for help, and \'exit' to quit.

From inside the embedded shell, you can run other commands directly:
$ version
Spring CLI v2.1.2.BUILD-SNAPSHOT

The embedded shell supports ANSI color output as well as tab completion. If you need to run a native command, you can use the ! prefix. To exit
the embedded shell, press ctrl-c .

67.6 Adding Extensions to the CLI
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You can add extensions to the CLI by using the install command. The command takes one or more sets of artifact coordinates in the format
group:artifact:version , as shown in the following example:
$ spring install com.example:spring-boot-cli-extension:1.0.0.RELEASE

In addition to installing the artifacts identified by the coordinates you supply, all of the artifacts' dependencies are also installed.
To uninstall a dependency, use the uninstall command. As with the install command, it takes one or more sets of artifact coordinates in the
format of group:artifact:version , as shown in the following example:
$ spring uninstall com.example:spring-boot-cli-extension:1.0.0.RELEASE

It uninstalls the artifacts identified by the coordinates you supply and their dependencies.
To uninstall all additional dependencies, you can use the --all option, as shown in the following example:
$ spring uninstall --all

68. Developing Applications with the Groovy Beans DSL
Spring Framework 4.0 has native support for a beans{} “DSL” (borrowed from Grails), and you can embed bean definitions in your Groovy
application scripts by using the same format. This is sometimes a good way to include external features like middleware declarations, as shown in
the following example:
@Configuration
class Application implements CommandLineRunner {
@Autowired
SharedService service
@Override
void run(String... args) {
println service.message
}
}
import my.company.SharedService
beans {
service(SharedService) {
message = "Hello World"
}
}

You can mix class declarations with beans{} in the same file as long as they stay at the top level, or, if you prefer, you can put the beans DSL in a
separate file.

69. Configuring the CLI with settings.xml
The Spring Boot CLI uses Aether, Maven’s dependency resolution engine, to resolve dependencies. The CLI makes use of the Maven configuration
found in ~/.m2/settings.xml to configure Aether. The following configuration settings are honored by the CLI:
Offline
Mirrors
Servers
Proxies
Profiles
Activation
Repositories
Active profiles
See Maven’s settings documentation for further information.
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70. What to Read Next
There are some sample groovy scripts available from the GitHub repository that you can use to try out the Spring Boot CLI. There is also extensive
Javadoc throughout the source code.
If you find that you reach the limit of the CLI tool, you probably want to look at converting your application to a full Gradle or Maven built “Groovy
project”. The next section covers Spring Boot’s "Build tool plugins", which you can use with Gradle or Maven.

Part VIII. Build tool plugins
Spring Boot provides build tool plugins for Maven and Gradle. The plugins offer a variety of features, including the packaging of executable jars. This
section provides more details on both plugins as well as some help should you need to extend an unsupported build system. If you are just getting
started, you might want to read “Chapter 13, Build Systems” from the “Part III, “Using Spring Boot”” section first.

71. Spring Boot Maven Plugin
The Spring Boot Maven Plugin provides Spring Boot support in Maven, letting you package executable jar or war archives and run an application
“in-place”. To use it, you must use Maven 3.2 (or later).

See the Spring Boot Maven Plugin Site for complete plugin documentation.

71.1 Including the Plugin
To use the Spring Boot Maven Plugin, include the appropriate XML in the plugins section of your pom.xml , as shown in the following example:


4.0.0




org.springframework.boot
spring-boot-maven-plugin
2.1.2.BUILD-SNAPSHOT



repackage








The preceding configuration repackages a jar or war that is built during the package phase of the Maven lifecycle. The following example shows
both the repackaged jar as well as the original jar in the target directory:
$ mvn package
$ ls target/*.jar
target/myproject-1.0.0.jar target/myproject-1.0.0.jar.original

If you do not include the  configuration, as shown in the prior example, you can run the plugin on its own (but only if the package
goal is used as well), as shown in the following example:
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$ mvn package spring-boot:repackage
$ ls target/*.jar
target/myproject-1.0.0.jar target/myproject-1.0.0.jar.original

If you use a milestone or snapshot release, you also need to add the appropriate pluginRepository elements, as shown in the following listing:


spring-snapshots
https://repo.spring.io/snapshot


spring-milestones
https://repo.spring.io/milestone



71.2 Packaging Executable Jar and War Files
Once spring-boot-maven-plugin has been included in your pom.xml , it automatically tries to rewrite archives to make them executable by
using the spring-boot:repackage goal. You should configure your project to build a jar or war (as appropriate) by using the usual packaging
element, as shown in the following example:



jar



Your existing archive is enhanced by Spring Boot during the package phase. The main class that you want to launch can be specified either by
using a configuration option or by adding a Main-Class attribute to the manifest in the usual way. If you do not specify a main class, the plugin
searches for a class with a public static void main(String[] args) method.
To build and run a project artifact, you can type the following:
$ mvn package
$ java -jar target/mymodule-0.0.1-SNAPSHOT.jar

To build a war file that is both executable and deployable into an external container, you need to mark the embedded container dependencies as
“provided”, as shown in the following example:



war



org.springframework.boot
spring-boot-starter-web


org.springframework.boot
spring-boot-starter-tomcat
provided





See the “Section 92.1, “Create a Deployable War File”” section for more details on how to create a deployable war file.
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Advanced configuration options and examples are available in the plugin info page.

72. Spring Boot Gradle Plugin
The Spring Boot Gradle Plugin provides Spring Boot support in Gradle, letting you package executable jar or war archives, run Spring Boot
applications, and use the dependency management provided by spring-boot-dependencies . It requires Gradle 4.4 or later. Please refer to the
plugin’s documentation to learn more:
Reference (HTML and PDF)
API

73. Spring Boot AntLib Module
The Spring Boot AntLib module provides basic Spring Boot support for Apache Ant. You can use the module to create executable jars. To use the
module, you need to declare an additional spring-boot namespace in your build.xml , as shown in the following example:

...


You need to remember to start Ant using the -lib option, as shown in the following example:
$ ant -lib 

The “Using Spring Boot” section includes a more complete example of using Apache Ant with spring-boot-antlib .

73.1 Spring Boot Ant Tasks
Once the spring-boot-antlib namespace has been declared, the following additional tasks are available:
Section 73.1.1, “ spring-boot:exejar ”
Section 73.2, “ spring-boot:findmainclass ”

73.1.1 spring-boot:exejar
You can use the exejar task to create a Spring Boot executable jar. The following attributes are supported by the task:
Attribute

Description

Required

destfile

The destination jar file to create

Yes

classes

The root directory of Java class files

Yes

start-class

The main application class to run

No (the default is the first class found that declares a main method)

The following nested elements can be used with the task:
Element

Description

resources

One or more Resource Collections describing a set of Resources that should be added to the content of the created jar file.

lib

One or more Resource Collections that should be added to the set of jar libraries that make up the runtime dependency
classpath of the application.

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73.1.2 Examples
This section shows two examples of Ant tasks.
Specify start-class.









Detect start-class.






73.2 spring-boot:findmainclass
The findmainclass task is used internally by exejar to locate a class declaring a main . If necessary, you can also use this task directly in your
build. The following attributes are supported:
Attribute

Description

Required

classesroot

The root directory of Java class files

Yes (unless mainclass is specified)

mainclass

Can be used to short-circuit the main class search

No

property

The Ant property that should be set with the result

No (result will be logged if unspecified)

73.2.1 Examples
This section contains three examples of using findmainclass .
Find and log.


Find and set.


Override and set.


74. Supporting Other Build Systems
If you want to use a build tool other than Maven, Gradle, or Ant, you likely need to develop your own plugin. Executable jars need to follow a specific
format and certain entries need to be written in an uncompressed form (see the “executable jar format” section in the appendix for details).
The Spring Boot Maven and Gradle plugins both make use of spring-boot-loader-tools to actually generate jars. If you need to, you may use
this library directly.

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74.1 Repackaging Archives
To repackage an existing archive so that it becomes a self-contained executable archive, use
org.springframework.boot.loader.tools.Repackager . The Repackager class takes a single constructor argument that refers to an existing
jar or war archive. Use one of the two available repackage() methods to either replace the original file or write to a new destination. Various
settings can also be configured on the repackager before it is run.

74.2 Nested Libraries
When repackaging an archive, you can include references to dependency files by using the
org.springframework.boot.loader.tools.Libraries interface. We do not provide any concrete implementations of Libraries here as they
are usually build-system-specific.
If your archive already includes libraries, you can use Libraries.NONE .

74.3 Finding a Main Class
If you do not use Repackager.setMainClass() to specify a main class, the repackager uses ASM to read class files and tries to find a suitable
class with a public static void main(String[] args) method. An exception is thrown if more than one candidate is found.

74.4 Example Repackage Implementation
The following example shows a typical repackage implementation:
Repackager repackager = new Repackager(sourceJarFile);
repackager.setBackupSource(false);
repackager.repackage(new Libraries() {
@Override
public void doWithLibraries(LibraryCallback callback) throws IOException {
// Build system specific implementation, callback for each dependency
// callback.library(new Library(nestedFile, LibraryScope.COMPILE));
}
});

75. What to Read Next
If you are interested in how the build tool plugins work, you can look at the spring-boot-tools module on GitHub. More technical details of the
executable jar format are covered in the appendix.
If you have specific build-related questions, you can check out the “how-to” guides.

Part IX. ‘How-to’ guides
This section provides answers to some common ‘how do I do that…’ questions that often arise when using Spring Boot. Its coverage is not
exhaustive, but it does cover quite a lot.
If you have a specific problem that we do not cover here, you might want to check out stackoverflow.com to see if someone has already provided an
answer. This is also a great place to ask new questions (please use the spring-boot tag).
We are also more than happy to extend this section. If you want to add a ‘how-to’, send us a pull request.

76. Spring Boot Application
This section includes topics relating directly to Spring Boot applications.

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76.1 Create Your Own FailureAnalyzer
FailureAnalyzer is a great way to intercept an exception on startup and turn it into a human-readable message, wrapped in a
FailureAnalysis . Spring Boot provides such an analyzer for application-context-related exceptions, JSR-303 validations, and more. You can also
create your own.
AbstractFailureAnalyzer is a convenient extension of FailureAnalyzer that checks the presence of a specified exception type in the
exception to handle. You can extend from that so that your implementation gets a chance to handle the exception only when it is actually present. If,
for whatever reason, you cannot handle the exception, return null to give another implementation a chance to handle the exception.
FailureAnalyzer implementations must be registered in META-INF/spring.factories . The following example registers
ProjectConstraintViolationFailureAnalyzer :
org.springframework.boot.diagnostics.FailureAnalyzer=\
com.example.ProjectConstraintViolationFailureAnalyzer

If you need access to the BeanFactory or the Environment , your FailureAnalyzer can simply implement BeanFactoryAware
or EnvironmentAware respectively.

76.2 Troubleshoot Auto-configuration
The Spring Boot auto-configuration tries its best to “do the right thing”, but sometimes things fail, and it can be hard to tell why.
There is a really useful ConditionEvaluationReport available in any Spring Boot ApplicationContext . You can see it if you enable DEBUG
logging output. If you use the spring-boot-actuator (see the Actuator chapter), there is also a conditions endpoint that renders the report in
JSON. Use that endpoint to debug the application and see what features have been added (and which have not been added) by Spring Boot at
runtime.
Many more questions can be answered by looking at the source code and the Javadoc. When reading the code, remember the following rules of
thumb:
Look for classes called *AutoConfiguration and read their sources. Pay special attention to the @Conditional* annotations to find out
what features they enable and when. Add --debug to the command line or a System property -Ddebug to get a log on the console of all the
auto-configuration decisions that were made in your app. In a running Actuator app, look at the conditions endpoint
( /actuator/conditions or the JMX equivalent) for the same information.
Look for classes that are @ConfigurationProperties (such as ServerProperties ) and read from there the available external configuration
options. The @ConfigurationProperties annotation has a name attribute that acts as a prefix to external properties. Thus,
ServerProperties has prefix="server" and its configuration properties are server.port , server.address , and others. In a running
Actuator app, look at the configprops endpoint.
Look for uses of the bind method on the Binder to pull configuration values explicitly out of the Environment in a relaxed manner. It is often
used with a prefix.
Look for @Value annotations that bind directly to the Environment .
Look for @ConditionalOnExpression annotations that switch features on and off in response to SpEL expressions, normally evaluated with
placeholders resolved from the Environment .

76.3 Customize the Environment or ApplicationContext Before It Starts
A SpringApplication has ApplicationListeners and ApplicationContextInitializers that are used to apply customizations to the
context or environment. Spring Boot loads a number of such customizations for use internally from META-INF/spring.factories . There is more
than one way to register additional customizations:
Programmatically, per application, by calling the addListeners and addInitializers methods on SpringApplication before you run it.
Declaratively, per application, by setting the context.initializer.classes or context.listener.classes properties.
Declaratively, for all applications, by adding a META-INF/spring.factories and packaging a jar file that the applications all use as a library.
The SpringApplication sends some special ApplicationEvents to the listeners (some even before the context is created) and then registers
the listeners for events published by the ApplicationContext as well. See “Section 23.5, “Application Events and Listeners”” in the ‘Spring Boot
features’ section for a complete list.

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It is also possible to customize the Environment before the application context is refreshed by using EnvironmentPostProcessor . Each
implementation should be registered in META-INF/spring.factories , as shown in the following example:
org.springframework.boot.env.EnvironmentPostProcessor=com.example.YourEnvironmentPostProcessor

The implementation can load arbitrary files and add them to the Environment . For instance, the following example loads a YAML configuration file
from the classpath:
public class EnvironmentPostProcessorExample implements EnvironmentPostProcessor {
private final YamlPropertySourceLoader loader = new YamlPropertySourceLoader();
@Override
public void postProcessEnvironment(ConfigurableEnvironment environment,
SpringApplication application) {
Resource path = new ClassPathResource("com/example/myapp/config.yml");
PropertySource propertySource = loadYaml(path);
environment.getPropertySources().addLast(propertySource);
}
private PropertySource loadYaml(Resource path) {
if (!path.exists()) {
throw new IllegalArgumentException("Resource " + path + " does not exist");
}
try {
return this.loader.load("custom-resource", path).get(0);
}
catch (IOException ex) {
throw new IllegalStateException(
"Failed to load yaml configuration from " + path, ex);
}
}
}

The Environment has already been prepared with all the usual property sources that Spring Boot loads by default. It is therefore
possible to get the location of the file from the environment. The preceding example adds the custom-resource property source at
the end of the list so that a key defined in any of the usual other locations takes precedence. A custom implementation may define
another order.

Caution
While using @PropertySource on your @SpringBootApplication may seem to be a convenient and easy way to load a
custom resource in the Environment , we do not recommend it, because Spring Boot prepares the Environment before
the ApplicationContext is refreshed. Any key defined with @PropertySource is loaded too late to have any effect on
auto-configuration.

76.4 Build an ApplicationContext Hierarchy (Adding a Parent or Root Context)
You can use the ApplicationBuilder class to create parent/child ApplicationContext hierarchies. See “Section 23.4, “Fluent Builder API”” in
the ‘Spring Boot features’ section for more information.

76.5 Create a Non-web Application
Not all Spring applications have to be web applications (or web services). If you want to execute some code in a main method but also bootstrap a
Spring application to set up the infrastructure to use, you can use the SpringApplication features of Spring Boot. A SpringApplication
changes its ApplicationContext class, depending on whether it thinks it needs a web application or not. The first thing you can do to help it is to
leave server-related dependencies (e.g. servlet API) off the classpath. If you cannot do that (for example, you run two applications from the same
code base) then you can explicitly call setWebApplicationType(WebApplicationType.NONE) on your SpringApplication instance or set the

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applicationContextClass property (through the Java API or with external properties). Application code that you want to run as your business
logic can be implemented as a CommandLineRunner and dropped into the context as a @Bean definition.

77. Properties and Configuration
This section includes topics about setting and reading properties and configuration settings and their interaction with Spring Boot applications.

77.1 Automatically Expand Properties at Build Time
Rather than hardcoding some properties that are also specified in your project’s build configuration, you can automatically expand them by instead
using the existing build configuration. This is possible in both Maven and Gradle.

77.1.1 Automatic Property Expansion Using Maven
You can automatically expand properties from the Maven project by using resource filtering. If you use the spring-boot-starter-parent , you
can then refer to your Maven ‘project properties’ with @..@ placeholders, as shown in the following example:
app.encoding=@project.build.sourceEncoding@
app.java.version=@java.version@

Only production configuration is filtered that way (in other words, no filtering is applied on src/test/resources ).

If you enable the addResources flag, the spring-boot:run goal can add src/main/resources directly to the classpath (for hot
reloading purposes). Doing so circumvents the resource filtering and this feature. Instead, you can use the exec:java goal or
customize the plugin’s configuration. See the plugin usage page for more details.

If you do not use the starter parent, you need to include the following element inside the  element of your pom.xml :


src/main/resources
true



You also need to include the following element inside  :

org.apache.maven.plugins
maven-resources-plugin
2.7


@

false



The useDefaultDelimiters property is important if you use standard Spring placeholders (such as ${placeholder} ) in your
configuration. If that property is not set to false , these may be expanded by the build.

77.1.2 Automatic Property Expansion Using Gradle
You can automatically expand properties from the Gradle project by configuring the Java plugin’s processResources task to do so, as shown in
the following example:
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processResources {
expand(project.properties)
}

You can then refer to your Gradle project’s properties by using placeholders, as shown in the following example:
app.name=${name}
app.description=${description}

Gradle’s expand method uses Groovy’s SimpleTemplateEngine , which transforms ${..} tokens. The ${..} style conflicts with
Spring’s own property placeholder mechanism. To use Spring property placeholders together with automatic expansion, escape the
Spring property placeholders as follows: \${..} .

77.2 Externalize the Configuration of SpringApplication
A SpringApplication has bean properties (mainly setters), so you can use its Java API as you create the application to modify its behavior.
Alternatively, you can externalize the configuration by setting properties in spring.main.* . For example, in application.properties , you
might have the following settings:
spring.main.web-application-type=none
spring.main.banner-mode=off

Then the Spring Boot banner is not printed on startup, and the application is not starting an embedded web server.
Properties defined in external configuration override the values specified with the Java API, with the notable exception of the sources used to create
the ApplicationContext . Consider the following application:
new SpringApplicationBuilder()
.bannerMode(Banner.Mode.OFF)
.sources(demo.MyApp.class)
.run(args);

Now consider the following configuration:
spring.main.sources=com.acme.Config,com.acme.ExtraConfig
spring.main.banner-mode=console

The actual application now shows the banner (as overridden by configuration) and uses three sources for the ApplicationContext (in the
following order): demo.MyApp , com.acme.Config , and com.acme.ExtraConfig .

77.3 Change the Location of External Properties of an Application
By default, properties from different sources are added to the Spring Environment in a defined order (see “Chapter 24, Externalized Configuration”
in the ‘Spring Boot features’ section for the exact order).
A nice way to augment and modify this ordering is to add @PropertySource annotations to your application sources. Classes passed to the
SpringApplication static convenience methods and those added using setSources() are inspected to see if they have @PropertySources . If
they do, those properties are added to the Environment early enough to be used in all phases of the ApplicationContext lifecycle. Properties
added in this way have lower priority than any added by using the default locations (such as application.properties ), system properties,
environment variables, or the command line.
You can also provide the following System properties (or environment variables) to change the behavior:
spring.config.name ( SPRING_CONFIG_NAME ): Defaults to application as the root of the file name.
spring.config.location ( SPRING_CONFIG_LOCATION ): The file to load (such as a classpath resource or a URL). A separate Environment
property source is set up for this document and it can be overridden by system properties, environment variables, or the command line.
No matter what you set in the environment, Spring Boot always loads application.properties as described above. By default, if YAML is used,
then files with the ‘.yml’ extension are also added to the list.
Spring Boot logs the configuration files that are loaded at the DEBUG level and the candidates it has not found at TRACE level.
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See ConfigFileApplicationListener for more detail.

77.4 Use ‘Short’ Command Line Arguments
Some people like to use (for example) --port=9000 instead of --server.port=9000 to set configuration properties on the command line. You
can enable this behavior by using placeholders in application.properties , as shown in the following example:
server.port=${port:8080}

If you inherit from the spring-boot-starter-parent POM, the default filter token of the maven-resources-plugins has been
changed from ${*} to @ (that is, @maven.token@ instead of ${maven.token} ) to prevent conflicts with Spring-style placeholders.
If you have enabled Maven filtering for the application.properties directly, you may want to also change the default filter token to
use other delimiters.

In this specific case, the port binding works in a PaaS environment such as Heroku or Cloud Foundry. In those two platforms, the
PORT environment variable is set automatically and Spring can bind to capitalized synonyms for Environment properties.

77.5 Use YAML for External Properties
YAML is a superset of JSON and, as such, is a convenient syntax for storing external properties in a hierarchical format, as shown in the following
example:
spring:
application:
name: cruncher
datasource:
driverClassName: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost/test
server:
port: 9000

Create a file called application.yml and put it in the root of your classpath. Then add snakeyaml to your dependencies (Maven coordinates
org.yaml:snakeyaml , already included if you use the spring-boot-starter ). A YAML file is parsed to a Java Map (like a
JSON object), and Spring Boot flattens the map so that it is one level deep and has period-separated keys, as many people are used to with
Properties files in Java.
The preceding example YAML corresponds to the following application.properties file:
spring.application.name=cruncher
spring.datasource.driverClassName=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost/test
server.port=9000

See “Section 24.7, “Using YAML Instead of Properties”” in the ‘Spring Boot features’ section for more information about YAML.

77.6 Set the Active Spring Profiles
The Spring Environment has an API for this, but you would normally set a System property ( spring.profiles.active ) or an OS environment
variable ( SPRING_PROFILES_ACTIVE ). Also, you can launch your application with a -D argument (remember to put it before the main class or jar
archive), as follows:
$ java -jar -Dspring.profiles.active=production demo-0.0.1-SNAPSHOT.jar

In Spring Boot, you can also set the active profile in application.properties , as shown in the following example:
spring.profiles.active=production

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A value set this way is replaced by the System property or environment variable setting but not by the SpringApplicationBuilder.profiles()
method. Thus, the latter Java API can be used to augment the profiles without changing the defaults.
See “Chapter 25, Profiles” in the “Spring Boot features” section for more information.

77.7 Change Configuration Depending on the Environment
A YAML file is actually a sequence of documents separated by --- lines, and each document is parsed separately to a flattened map.
If a YAML document contains a spring.profiles key, then the profiles value (a comma-separated list of profiles) is fed into the Spring
Environment.acceptsProfiles() method. If any of those profiles is active, that document is included in the final merge (otherwise, it is not), as
shown in the following example:
server:
port: 9000
--spring:
profiles: development
server:
port: 9001
--spring:
profiles: production
server:
port: 0

In the preceding example, the default port is 9000. However, if the Spring profile called ‘development’ is active, then the port is 9001. If ‘production’
is active, then the port is 0.

The YAML documents are merged in the order in which they are encountered. Later values override earlier values.

To do the same thing with properties files, you can use application-${profile}.properties to specify profile-specific values.

77.8 Discover Built-in Options for External Properties
Spring Boot binds external properties from application.properties (or .yml files and other places) into an application at runtime. There is not
(and technically cannot be) an exhaustive list of all supported properties in a single location, because contributions can come from additional jar files
on your classpath.
A running application with the Actuator features has a configprops endpoint that shows all the bound and bindable properties available through
@ConfigurationProperties .
The appendix includes an application.properties example with a list of the most common properties supported by Spring Boot. The definitive
list comes from searching the source code for @ConfigurationProperties and @Value annotations as well as the occasional use of Binder .
For more about the exact ordering of loading properties, see "Chapter 24, Externalized Configuration".

78. Embedded Web Servers
Each Spring Boot web application includes an embedded web server. This feature leads to a number of how-to questions, including how to change
the embedded server and how to configure the embedded server. This section answers those questions.

78.1 Use Another Web Server
Many Spring Boot starters include default embedded containers.
For servlet stack applications, the spring-boot-starter-web includes Tomcat by including spring-boot-starter-tomcat , but you can
use spring-boot-starter-jetty or spring-boot-starter-undertow instead.
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For reactive stack applications, the spring-boot-starter-webflux includes Reactor Netty by including
spring-boot-starter-reactor-netty , but you can use spring-boot-starter-tomcat , spring-boot-starter-jetty , or
spring-boot-starter-undertow instead.
When switching to a different HTTP server, you need to exclude the default dependencies in addition to including the one you need. Spring Boot
provides separate starters for HTTP servers to help make this process as easy as possible.
The following Maven example shows how to exclude Tomcat and include Jetty for Spring MVC:

3.1.0


org.springframework.boot
spring-boot-starter-web



org.springframework.boot
spring-boot-starter-tomcat





org.springframework.boot
spring-boot-starter-jetty


The version of the Servlet API has been overridden as, unlike Tomcat 9 and Undertow 2.0, Jetty 9.4 does not support Servlet 4.0.

The following Gradle example shows how to exclude Netty and include Undertow for Spring WebFlux:
configurations {
// exclude Reactor Netty
compile.exclude module: 'spring-boot-starter-reactor-netty'
}
dependencies {
compile 'org.springframework.boot:spring-boot-starter-webflux'
// Use Undertow instead
compile 'org.springframework.boot:spring-boot-starter-undertow'
// ...
}

spring-boot-starter-reactor-netty is required to use the WebClient class, so you may need to keep a dependency on Netty
even when you need to include a different HTTP server.

78.2 Disabling the Web Server
If your classpath contains the necessary bits to start a web server, Spring Boot will automatically start it. To disable this behaviour configure the
WebApplicationType in your application.properties , as shown in the following example:
spring.main.web-application-type=none

78.3 Change the HTTP Port
In a standalone application, the main HTTP port defaults to 8080 but can be set with server.port (for example, in application.properties
or as a System property). Thanks to relaxed binding of Environment values, you can also use SERVER_PORT (for example, as an OS environment
variable).
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To switch off the HTTP endpoints completely but still create a WebApplicationContext , use server.port=-1 . (Doing so is sometimes useful for
testing.)
For more details, see “Section 28.4.4, “Customizing Embedded Servlet Containers”” in the ‘Spring Boot features’ section, or the
ServerProperties source code.

78.4 Use a Random Unassigned HTTP Port
To scan for a free port (using OS natives to prevent clashes) use server.port=0 .

78.5 Discover the HTTP Port at Runtime
You can access the port the server is running on from log output or from the ServletWebServerApplicationContext through its WebServer .
The best way to get that and be sure that it has been initialized is to add a @Bean of type
ApplicationListener and pull the container out of the event when it is published.
Tests that use @SpringBootTest(webEnvironment=WebEnvironment.RANDOM_PORT) can also inject the actual port into a field by using the
@LocalServerPort annotation, as shown in the following example:
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(webEnvironment=WebEnvironment.RANDOM_PORT)
public class MyWebIntegrationTests {
@Autowired
ServletWebServerApplicationContext server;
@LocalServerPort
int port;
// ...
}

@LocalServerPort is a meta-annotation for @Value("${local.server.port}") . Do not try to inject the port in a regular
application. As we just saw, the value is set only after the container has been initialized. Contrary to a test, application code callbacks
are processed early (before the value is actually available).

78.6 Enable HTTP Response Compression
HTTP response compression is supported by Jetty, Tomcat, and Undertow. It can be enabled in application.properties , as follows:
server.compression.enabled=true

By default, responses must be at least 2048 bytes in length for compression to be performed. You can configure this behavior by setting the
server.compression.min-response-size property.
By default, responses are compressed only if their content type is one of the following:
text/html
text/xml
text/plain
text/css
text/javascript
application/javascript
application/json
application/xml
You can configure this behavior by setting the server.compression.mime-types property.

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78.7 Configure SSL
SSL can be configured declaratively by setting the various server.ssl.* properties, typically in application.properties or
application.yml . The following example shows setting SSL properties in application.properties :
server.port=8443
server.ssl.key-store=classpath:keystore.jks
server.ssl.key-store-password=secret
server.ssl.key-password=another-secret

See Ssl for details of all of the supported properties.
Using configuration such as the preceding example means the application no longer supports a plain HTTP connector at port 8080. Spring Boot
does not support the configuration of both an HTTP connector and an HTTPS connector through application.properties . If you want to have
both, you need to configure one of them programmatically. We recommend using application.properties to configure HTTPS, as the HTTP
connector is the easier of the two to configure programmatically. See the spring-boot-sample-tomcat-multi-connectors sample project for an
example.

78.8 Configure HTTP/2
You can enable HTTP/2 support in your Spring Boot application with the server.http2.enabled configuration property. This support depends on
the chosen web server and the application environment, since that protocol is not supported out-of-the-box by JDK8.

Spring Boot does not support h2c , the cleartext version of the HTTP/2 protocol. So you must configure SSL first.

78.8.1 HTTP/2 with Undertow
As of Undertow 1.4.0+, HTTP/2 is supported without any additional requirement on JDK8.

78.8.2 HTTP/2 with Jetty
As of Jetty 9.4.8, HTTP/2 is also supported with the Conscrypt library. To enable that support, your application needs to have two additional
dependencies: org.eclipse.jetty:jetty-alpn-conscrypt-server and org.eclipse.jetty.http2:http2-server .

78.8.3 HTTP/2 with Tomcat
Spring Boot ships by default with Tomcat 9.0.x which supports HTTP/2 out of the box when using JDK 9 or later. Alternatively, HTTP/2 can be used
on JDK 8 if the libtcnative library and its dependencies are installed on the host operating system.
The library folder must be made available, if not already, to the JVM library path. You can do so with a JVM argument such as
-Djava.library.path=/usr/local/opt/tomcat-native/lib . More on this in the official Tomcat documentation.
Starting Tomcat 9.0.x on JDK 8 without that native support logs the following error:
ERROR 8787 --- [

main] o.a.coyote.http11.Http11NioProtocol

: The upgrade handler [org.apache.coyote.http2.Http2

This error is not fatal, and the application still starts with HTTP/1.1 SSL support.

78.8.4 HTTP/2 with Reactor Netty
The spring-boot-webflux-starter is using by default Reactor Netty as a server. Reactor Netty can be configured for HTTP/2 using the JDK
support with JDK 9 or later. For JDK 8 environments, or for optimal runtime performance, this server also supports HTTP/2 with native libraries. To
enable that, your application needs to have an additional dependency.
Spring Boot manages the version for the io.netty:netty-tcnative-boringssl-static "uber jar", containing native libraries for all platforms.
Developers can choose to import only the required dependencies using a classifier (see the Netty official documentation).

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78.9 Configure the Web Server
Generally, you should first consider using one of the many available configuration keys and customize your web server by adding new entries in
your application.properties (or application.yml , or environment, etc. see “Section 77.8, “Discover Built-in Options for External
Properties””). The server.* namespace is quite useful here, and it includes namespaces like server.tomcat.* , server.jetty.* and others,
for server-specific features. See the list of Appendix A, Common application properties.
The previous sections covered already many common use cases, such as compression, SSL or HTTP/2. However, if a configuration key doesn’t
exist for your use case, you should then look at WebServerFactoryCustomizer . You can declare such a component and get access to the server
factory relevant to your choice: you should select the variant for the chosen Server (Tomcat, Jetty, Reactor Netty, Undertow) and the chosen web
stack (Servlet or Reactive).
The example below is for Tomcat with the spring-boot-starter-web (Servlet stack):
@Component
public class MyTomcatWebServerCustomizer
implements WebServerFactoryCustomizer {
@Override
public void customize(TomcatServletWebServerFactory factory) {
// customize the factory here
}
}

In addition Spring Boot provides:
Server

Servlet stack

Reactive stack

Tomcat

TomcatServletWebServerFactory

TomcatReactiveWebServerFactory

Jetty

JettyServletWebServerFactory

JettyReactiveWebServerFactory

Undertow

UndertowServletWebServerFactory

UndertowReactiveWebServerFactory

Reactor

N/A

NettyReactiveWebServerFactory

Once you’ve got access to a WebServerFactory , you can often add customizers to it to configure specific parts, like connectors, server resources,
or the server itself - all using server-specific APIs.
As a last resort, you can also declare your own WebServerFactory component, which will override the one provided by Spring Boot. In this case,
you can’t rely on configuration properties in the server namespace anymore.

78.10 Add a Servlet, Filter, or Listener to an Application
In a servlet stack application, i.e. with the spring-boot-starter-web , there are two ways to add Servlet , Filter ,
ServletContextListener , and the other listeners supported by the Servlet API to your application:
Section 78.10.1, “Add a Servlet, Filter, or Listener by Using a Spring Bean”
Section 78.10.2, “Add Servlets, Filters, and Listeners by Using Classpath Scanning”

78.10.1 Add a Servlet, Filter, or Listener by Using a Spring Bean
To add a Servlet , Filter , or Servlet *Listener by using a Spring bean, you must provide a @Bean definition for it. Doing so can be very
useful when you want to inject configuration or dependencies. However, you must be very careful that they do not cause eager initialization of too
many other beans, because they have to be installed in the container very early in the application lifecycle. (For example, it is not a good idea to
have them depend on your DataSource or JPA configuration.) You can work around such restrictions by initializing the beans lazily when first used
instead of on initialization.
In the case of Filters and Servlets , you can also add mappings and init parameters by adding a FilterRegistrationBean or a
ServletRegistrationBean instead of or in addition to the underlying component.

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If no dispatcherType is specified on a filter registration, REQUEST is used. This aligns with the Servlet Specification’s default
dispatcher type.

Like any other Spring bean, you can define the order of Servlet filter beans; please make sure to check the “the section called “Registering Servlets,
Filters, and Listeners as Spring Beans”” section.

Disable Registration of a Servlet or Filter
As described earlier, any Servlet or Filter beans are registered with the servlet container automatically. To disable registration of a particular
Filter or Servlet bean, create a registration bean for it and mark it as disabled, as shown in the following example:
@Bean
public FilterRegistrationBean registration(MyFilter filter) {
FilterRegistrationBean registration = new FilterRegistrationBean(filter);
registration.setEnabled(false);
return registration;
}

78.10.2 Add Servlets, Filters, and Listeners by Using Classpath Scanning
@WebServlet , @WebFilter , and @WebListener annotated classes can be automatically registered with an embedded servlet container by
annotating a @Configuration class with @ServletComponentScan and specifying the package(s) containing the components that you want to
register. By default, @ServletComponentScan scans from the package of the annotated class.

78.11 Configure Access Logging
Access logs can be configured for Tomcat, Undertow, and Jetty through their respective namespaces.
For instance, the following settings log access on Tomcat with a custom pattern.
server.tomcat.basedir=my-tomcat
server.tomcat.accesslog.enabled=true
server.tomcat.accesslog.pattern=%t %a "%r" %s (%D ms)

The default location for logs is a logs directory relative to the Tomcat base directory. By default, the logs directory is a temporary
directory, so you may want to fix Tomcat’s base directory or use an absolute path for the logs. In the preceding example, the logs are
available in my-tomcat/logs relative to the working directory of the application.

Access logging for Undertow can be configured in a similar fashion, as shown in the following example:
server.undertow.accesslog.enabled=true
server.undertow.accesslog.pattern=%t %a "%r" %s (%D ms)

Logs are stored in a logs directory relative to the working directory of the application. You can customize this location by setting the
server.undertow.accesslog.directory property.
Finally, access logging for Jetty can also be configured as follows:
server.jetty.accesslog.enabled=true
server.jetty.accesslog.filename=/var/log/jetty-access.log

By default, logs are redirected to System.err . For more details, see the Jetty documentation.

78.12 Running Behind a Front-end Proxy Server
Your application might need to send 302 redirects or render content with absolute links back to itself. When running behind a proxy, the caller wants
a link to the proxy and not to the physical address of the machine hosting your app. Typically, such situations are handled through a contract with the
proxy, which adds headers to tell the back end how to construct links to itself.

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If the proxy adds conventional X-Forwarded-For and X-Forwarded-Proto headers (most proxy servers do so), the absolute links should be
rendered correctly, provided server.use-forward-headers is set to true in your application.properties .

If your application runs in Cloud Foundry or Heroku, the server.use-forward-headers property defaults to true . In all other
instances, it defaults to false .

78.12.1 Customize Tomcat’s Proxy Configuration
If you use Tomcat, you can additionally configure the names of the headers used to carry “forwarded” information, as shown in the following
example:
server.tomcat.remote-ip-header=x-your-remote-ip-header
server.tomcat.protocol-header=x-your-protocol-header

Tomcat is also configured with a default regular expression that matches internal proxies that are to be trusted. By default, IP addresses in 10/8 ,
192.168/16 , 169.254/16 and 127/8 are trusted. You can customize the valve’s configuration by adding an entry to
application.properties , as shown in the following example:
server.tomcat.internal-proxies=192\\.168\\.\\d{1,3}\\.\\d{1,3}

The double backslashes are required only when you use a properties file for configuration. If you use YAML, single backslashes are
sufficient, and a value equivalent to that shown in the preceding example would be 192\.168\.\d{1,3}\.\d{1,3} .

You can trust all proxies by setting the internal-proxies to empty (but do not do so in production).

You can take complete control of the configuration of Tomcat’s RemoteIpValve by switching the automatic one off (to do so, set
server.use-forward-headers=false ) and adding a new valve instance in a TomcatServletWebServerFactory bean.

78.13 Enable Multiple Connectors with Tomcat
You can add an org.apache.catalina.connector.Connector to the TomcatServletWebServerFactory , which can allow multiple connectors,
including HTTP and HTTPS connectors, as shown in the following example:
@Bean
public ServletWebServerFactory servletContainer() {
TomcatServletWebServerFactory tomcat = new TomcatServletWebServerFactory();
tomcat.addAdditionalTomcatConnectors(createSslConnector());
return tomcat;
}
private Connector createSslConnector() {
Connector connector = new Connector("org.apache.coyote.http11.Http11NioProtocol");
Http11NioProtocol protocol = (Http11NioProtocol) connector.getProtocolHandler();
try {
File keystore = new ClassPathResource("keystore").getFile();
File truststore = new ClassPathResource("keystore").getFile();
connector.setScheme("https");
connector.setSecure(true);
connector.setPort(8443);
protocol.setSSLEnabled(true);
protocol.setKeystoreFile(keystore.getAbsolutePath());
protocol.setKeystorePass("changeit");
protocol.setTruststoreFile(truststore.getAbsolutePath());
protocol.setTruststorePass("changeit");
protocol.setKeyAlias("apitester");
return connector;
}
catch (IOException ex) {
throw new IllegalStateException("can't access keystore: [" + "keystore"
+ "] or truststore: [" + "keystore" + "]" ex);

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+

] or truststore: [

+

keystore

+

] , ex);

}
}

78.14 Use Tomcat’s LegacyCookieProcessor
By default, the embedded Tomcat used by Spring Boot does not support "Version 0" of the Cookie format, so you may see the following error:
java.lang.IllegalArgumentException: An invalid character [32] was present in the Cookie value

If at all possible, you should consider updating your code to only store values compliant with later Cookie specifications. If, however, you cannot
change the way that cookies are written, you can instead configure Tomcat to use a LegacyCookieProcessor . To switch to the
LegacyCookieProcessor , use an WebServerFactoryCustomizer bean that adds a TomcatContextCustomizer , as shown in the following
example:
@Bean
public WebServerFactoryCustomizer cookieProcessorCustomizer() {
return (factory) -> factory.addContextCustomizers(
(context) -> context.setCookieProcessor(new LegacyCookieProcessor()));
}

78.15 Enable Multiple Listeners with Undertow
Add an UndertowBuilderCustomizer to the UndertowServletWebServerFactory and add a listener to the Builder , as shown in the following
example:
@Bean
public UndertowServletWebServerFactory servletWebServerFactory() {
UndertowServletWebServerFactory factory = new UndertowServletWebServerFactory();
factory.addBuilderCustomizers(new UndertowBuilderCustomizer() {
@Override
public void customize(Builder builder) {
builder.addHttpListener(8080, "0.0.0.0");
}
});
return factory;
}

78.16 Create WebSocket Endpoints Using @ServerEndpoint
If you want to use @ServerEndpoint in a Spring Boot application that used an embedded container, you must declare a single
ServerEndpointExporter @Bean , as shown in the following example:
@Bean
public ServerEndpointExporter serverEndpointExporter() {
return new ServerEndpointExporter();
}

The bean shown in the preceding example registers any @ServerEndpoint annotated beans with the underlying WebSocket container. When
deployed to a standalone servlet container, this role is performed by a servlet container initializer, and the ServerEndpointExporter bean is not
required.

79. Spring MVC
Spring Boot has a number of starters that include Spring MVC. Note that some starters include a dependency on Spring MVC rather than include it
directly. This section answers common questions about Spring MVC and Spring Boot.

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79.1 Write a JSON REST Service
Any Spring @RestController in a Spring Boot application should render JSON response by default as long as Jackson2 is on the classpath, as
shown in the following example:
@RestController
public class MyController {
@RequestMapping("/thing")
public MyThing thing() {
return new MyThing();
}
}

As long as MyThing can be serialized by Jackson2 (true for a normal POJO or Groovy object), then localhost:8080/thing serves a JSON
representation of it by default. Note that, in a browser, you might sometimes see XML responses, because browsers tend to send accept headers
that prefer XML.

79.2 Write an XML REST Service
If you have the Jackson XML extension ( jackson-dataformat-xml ) on the classpath, you can use it to render XML responses. The previous
example that we used for JSON would work. To use the Jackson XML renderer, add the following dependency to your project:

com.fasterxml.jackson.dataformat
jackson-dataformat-xml


If Jackson’s XML extension is not available, JAXB (provided by default in the JDK) is used, with the additional requirement of having MyThing
annotated as @XmlRootElement , as shown in the following example:
@XmlRootElement
public class MyThing {
private String name;
// .. getters and setters
}

To get the server to render XML instead of JSON, you might have to send an Accept: text/xml header (or use a browser).

79.3 Customize the Jackson ObjectMapper
Spring MVC (client and server side) uses HttpMessageConverters to negotiate content conversion in an HTTP exchange. If Jackson is on the
classpath, you already get the default converter(s) provided by Jackson2ObjectMapperBuilder , an instance of which is auto-configured for you.
The ObjectMapper (or XmlMapper for Jackson XML converter) instance (created by default) has the following customized properties:
MapperFeature.DEFAULT_VIEW_INCLUSION is disabled
DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES is disabled
SerializationFeature.WRITE_DATES_AS_TIMESTAMPS is disabled
Spring Boot also has some features to make it easier to customize this behavior.
You can configure the ObjectMapper and XmlMapper instances by using the environment. Jackson provides an extensive suite of simple on/off
features that can be used to configure various aspects of its processing. These features are described in six enums (in Jackson) that map onto
properties in the environment:
Enum

Property

Values

com.fasterxml.jackson.databind.DeserializationFeature

spring.jackson.deserialization.

true , false

com.fasterxml.jackson.core.JsonGenerator.Feature

spring.jackson.generator.

true , false

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Enum

Property

Values

com.fasterxml.jackson.databind.MapperFeature

spring.jackson.mapper.

true , false

com.fasterxml.jackson.core.JsonParser.Feature

spring.jackson.parser.

true , false

com.fasterxml.jackson.databind.SerializationFeature

spring.jackson.serialization.

true , false

com.fasterxml.jackson.annotation.JsonInclude.Include

spring.jackson.default-property-inclusion

always ,
non_null ,
non_absent ,
non_default ,
non_empty

For example, to enable pretty print, set spring.jackson.serialization.indent_output=true . Note that, thanks to the use of relaxed binding,
the case of indent_output does not have to match the case of the corresponding enum constant, which is INDENT_OUTPUT .
This environment-based configuration is applied to the auto-configured Jackson2ObjectMapperBuilder bean and applies to any mappers created
by using the builder, including the auto-configured ObjectMapper bean.
The context’s Jackson2ObjectMapperBuilder can be customized by one or more Jackson2ObjectMapperBuilderCustomizer beans. Such
customizer beans can be ordered (Boot’s own customizer has an order of 0), letting additional customization be applied both before and after Boot’s
customization.
Any beans of type com.fasterxml.jackson.databind.Module are automatically registered with the auto-configured
Jackson2ObjectMapperBuilder and are applied to any ObjectMapper instances that it creates. This provides a global mechanism for
contributing custom modules when you add new features to your application.
If you want to replace the default ObjectMapper completely, either define a @Bean of that type and mark it as @Primary or, if you prefer the
builder-based approach, define a Jackson2ObjectMapperBuilder @Bean . Note that, in either case, doing so disables all auto-configuration of the
ObjectMapper .
If you provide any @Beans of type MappingJackson2HttpMessageConverter , they replace the default value in the MVC configuration. Also, a
convenience bean of type HttpMessageConverters is provided (and is always available if you use the default MVC configuration). It has some
useful methods to access the default and user-enhanced message converters.
See the “Section 79.4, “Customize the @ResponseBody Rendering”” section and the WebMvcAutoConfiguration source code for more details.

79.4 Customize the @ResponseBody Rendering
Spring uses HttpMessageConverters to render @ResponseBody (or responses from @RestController ). You can contribute additional
converters by adding beans of the appropriate type in a Spring Boot context. If a bean you add is of a type that would have been included by default
anyway (such as MappingJackson2HttpMessageConverter for JSON conversions), it replaces the default value. A convenience bean of type
HttpMessageConverters is provided and is always available if you use the default MVC configuration. It has some useful methods to access the
default and user-enhanced message converters (For example, it can be useful if you want to manually inject them into a custom RestTemplate ).
As in normal MVC usage, any WebMvcConfigurer beans that you provide can also contribute converters by overriding the
configureMessageConverters method. However, unlike with normal MVC, you can supply only additional converters that you need (because
Spring Boot uses the same mechanism to contribute its defaults). Finally, if you opt out of the Spring Boot default MVC configuration by providing
your own @EnableWebMvc configuration, you can take control completely and do everything manually by using getMessageConverters from
WebMvcConfigurationSupport .
See the WebMvcAutoConfiguration source code for more details.

79.5 Handling Multipart File Uploads
Spring Boot embraces the Servlet 3 javax.servlet.http.Part API to support uploading files. By default, Spring Boot configures Spring MVC
with a maximum size of 1MB per file and a maximum of 10MB of file data in a single request. You may override these values, the location to which
intermediate data is stored (for example, to the /tmp directory), and the threshold past which data is flushed to disk by using the properties

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exposed in the MultipartProperties class. For example, if you want to specify that files be unlimited, set the
spring.servlet.multipart.max-file-size property to -1 .
The multipart support is helpful when you want to receive multipart encoded file data as a @RequestParam -annotated parameter of type
MultipartFile in a Spring MVC controller handler method.
See the MultipartAutoConfiguration source for more details.

It is recommended to use the container’s built-in support for multipart uploads rather than introducing an additional dependency such
as Apache Commons File Upload.

79.6 Switch Off the Spring MVC DispatcherServlet
By default, all content is served from the root of your application ( / ). If you would rather map to a different path, you can configure one as follows:
spring.mvc.servlet.path=/acme

If you have additional servlets you can declare a @Bean of type Servlet or ServletRegistrationBean for each and Spring Boot will register
them transparently to the container. Because servlets are registered that way, they can be mapped to a sub-context of the DispatcherServlet
without invoking it.
Configuring the DispatcherServlet yourself is unusual but if you really need to do it, a @Bean of type DispatcherServletPath must be
provided as well to provide the path of your custom DispatcherServlet .

79.7 Switch off the Default MVC Configuration
The easiest way to take complete control over MVC configuration is to provide your own @Configuration with the @EnableWebMvc annotation.
Doing so leaves all MVC configuration in your hands.

79.8 Customize ViewResolvers
A ViewResolver is a core component of Spring MVC, translating view names in @Controller to actual View implementations. Note that
ViewResolvers are mainly used in UI applications, rather than REST-style services (a View is not used to render a @ResponseBody ). There are
many implementations of ViewResolver to choose from, and Spring on its own is not opinionated about which ones you should use. Spring Boot,
on the other hand, installs one or two for you, depending on what it finds on the classpath and in the application context. The DispatcherServlet
uses all the resolvers it finds in the application context, trying each one in turn until it gets a result, so, if you add your own, you have to be aware of
the order and in which position your resolver is added.
WebMvcAutoConfiguration adds the following ViewResolvers to your context:
An InternalResourceViewResolver named ‘defaultViewResolver’. This one locates physical resources that can be rendered by using the
DefaultServlet (including static resources and JSP pages, if you use those). It applies a prefix and a suffix to the view name and then looks
for a physical resource with that path in the servlet context (the defaults are both empty but are accessible for external configuration through
spring.mvc.view.prefix and spring.mvc.view.suffix ). You can override it by providing a bean of the same type.
A BeanNameViewResolver named ‘beanNameViewResolver’. This is a useful member of the view resolver chain and picks up any beans with
the same name as the View being resolved. It should not be necessary to override or replace it.
A ContentNegotiatingViewResolver named ‘viewResolver’ is added only if there are actually beans of type View present. This is a
‘master’ resolver, delegating to all the others and attempting to find a match to the ‘Accept’ HTTP header sent by the client. There is a useful
blog about ContentNegotiatingViewResolver that you might like to study to learn more, and you might also look at the source code for
detail. You can switch off the auto-configured ContentNegotiatingViewResolver by defining a bean named ‘viewResolver’.
If you use Thymeleaf, you also have a ThymeleafViewResolver named ‘thymeleafViewResolver’. It looks for resources by surrounding the
view name with a prefix and suffix. The prefix is spring.thymeleaf.prefix , and the suffix is spring.thymeleaf.suffix . The values of the
prefix and suffix default to ‘classpath:/templates/’ and ‘.html’, respectively. You can override ThymeleafViewResolver by providing a bean of
the same name.
If you use FreeMarker, you also have a FreeMarkerViewResolver named ‘freeMarkerViewResolver’. It looks for resources in a loader path
(which is externalized to spring.freemarker.templateLoaderPath and has a default value of ‘classpath:/templates/’) by surrounding the
view name with a prefix and a suffix. The prefix is externalized to spring.freemarker.prefix , and the suffix is externalized to

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spring.freemarker.suffix . The default values of the prefix and suffix are empty and ‘.ftl’, respectively. You can override
FreeMarkerViewResolver by providing a bean of the same name.
If you use Groovy templates (actually, if groovy-templates is on your classpath), you also have a GroovyMarkupViewResolver named
‘groovyMarkupViewResolver’. It looks for resources in a loader path by surrounding the view name with a prefix and suffix (externalized to
spring.groovy.template.prefix and spring.groovy.template.suffix ). The prefix and suffix have default values of
‘classpath:/templates/’ and ‘.tpl’, respectively. You can override GroovyMarkupViewResolver by providing a bean of the same name.
For more detail, see the following sections:
WebMvcAutoConfiguration
ThymeleafAutoConfiguration
FreeMarkerAutoConfiguration
GroovyTemplateAutoConfiguration

80. Testing With Spring Security
Spring Security provides support for running tests as a specific user. For example, the test in the snippet below will run with an authenticated user
that has the ADMIN role.
@Test
@WithMockUser(roles="ADMIN")
public void requestProtectedUrlWithUser() throws Exception {
mvc
.perform(get("/"))
...
}

Spring Security provides comprehensive integration with Spring MVC Test and this can also be used when testing controllers using the
@WebMvcTest slice and MockMvc .
For additional details on Spring Security’s testing support, refer to Spring Security’s reference documentation).

81. Jersey
81.1 Secure Jersey endpoints with Spring Security
Spring Security can be used to secure a Jersey-based web application in much the same way as it can be used to secure a Spring MVC-based web
application. However, if you want to use Spring Security’s method-level security with Jersey, you must configure Jersey to use setStatus(int)
rather sendError(int) . This prevents Jersey from committing the response before Spring Security has had an opportunity to report an
authentication or authorization failure to the client.
The jersey.config.server.response.setStatusOverSendError property must be set to true on the application’s ResourceConfig bean,
as shown in the following example:
@Component
public class JerseyConfig extends ResourceConfig {
public JerseyConfig() {
register(Endpoint.class);
setProperties(Collections.singletonMap(
"jersey.config.server.response.setStatusOverSendError", true));
}
}

82. HTTP Clients
Spring Boot offers a number of starters that work with HTTP clients. This section answers questions related to using them.

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82.1 Configure RestTemplate to Use a Proxy
As described in Section 34.1, “RestTemplate Customization”, you can use a RestTemplateCustomizer with RestTemplateBuilder to build a
customized RestTemplate . This is the recommended approach for creating a RestTemplate configured to use a proxy.
The exact details of the proxy configuration depend on the underlying client request factory that is being used. The following example configures
HttpComponentsClientRequestFactory with an HttpClient that uses a proxy for all hosts except 192.168.0.5 :
static class ProxyCustomizer implements RestTemplateCustomizer {
@Override
public void customize(RestTemplate restTemplate) {
HttpHost proxy = new HttpHost("proxy.example.com");
HttpClient httpClient = HttpClientBuilder.create()
.setRoutePlanner(new DefaultProxyRoutePlanner(proxy) {
@Override
public HttpHost determineProxy(HttpHost target,
HttpRequest request, HttpContext context)
throws HttpException {
if (target.getHostName().equals("192.168.0.5")) {
return null;
}
return super.determineProxy(target, request, context);
}
}).build();
restTemplate.setRequestFactory(
new HttpComponentsClientHttpRequestFactory(httpClient));
}
}

83. Logging
Spring Boot has no mandatory logging dependency, except for the Commons Logging API, which is typically provided by Spring Framework’s
spring-jcl module. To use Logback, you need to include it and spring-jcl on the classpath. The simplest way to do that is through the
starters, which all depend on spring-boot-starter-logging . For a web application, you need only spring-boot-starter-web , since it
depends transitively on the logging starter. If you use Maven, the following dependency adds logging for you:

org.springframework.boot
spring-boot-starter-web


Spring Boot has a LoggingSystem abstraction that attempts to configure logging based on the content of the classpath. If Logback is available, it is
the first choice.
If the only change you need to make to logging is to set the levels of various loggers, you can do so in application.properties by using the
"logging.level" prefix, as shown in the following example:
logging.level.org.springframework.web=DEBUG
logging.level.org.hibernate=ERROR

You can also set the location of a file to which to write the log (in addition to the console) by using "logging.file".
To configure the more fine-grained settings of a logging system, you need to use the native configuration format supported by the LoggingSystem
in question. By default, Spring Boot picks up the native configuration from its default location for the system (such as classpath:logback.xml for
Logback), but you can set the location of the config file by using the "logging.config" property.

83.1 Configure Logback for Logging
If you put a logback.xml in the root of your classpath, it is picked up from there (or from logback-spring.xml , to take advantage of the
templating features provided by Boot). Spring Boot provides a default base configuration that you can include if you want to set levels, as shown in
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the following example:






If you look at base.xml in the spring-boot jar, you can see that it uses some useful System properties that the LoggingSystem takes care of
creating for you:
${PID} : The current process ID.
${LOG_FILE} : Whether logging.file was set in Boot’s external configuration.
${LOG_PATH} : Whether logging.path (representing a directory for log files to live in) was set in Boot’s external configuration.
${LOG_EXCEPTION_CONVERSION_WORD} : Whether logging.exception-conversion-word was set in Boot’s external configuration.
Spring Boot also provides some nice ANSI color terminal output on a console (but not in a log file) by using a custom Logback converter. See the
default base.xml configuration for details.
If Groovy is on the classpath, you should be able to configure Logback with logback.groovy as well. If present, this setting is given preference.

83.1.1 Configure Logback for File-only Output
If you want to disable console logging and write output only to a file, you need a custom logback-spring.xml that imports file-appender.xml
but not console-appender.xml , as shown in the following example:










You also need to add logging.file to your application.properties , as shown in the following example:
logging.file=myapplication.log

83.2 Configure Log4j for Logging
Spring Boot supports Log4j 2 for logging configuration if it is on the classpath. If you use the starters for assembling dependencies, you have to
exclude Logback and then include log4j 2 instead. If you do not use the starters, you need to provide (at least) spring-jcl in addition to Log4j 2.
The simplest path is probably through the starters, even though it requires some jiggling with excludes. The following example shows how to set up
the starters in Maven:

org.springframework.boot
spring-boot-starter-web


org.springframework.boot
spring-boot-starter


org.springframework.boot
spring-boot-starter-logging




org.springframework.boot

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spring-boot-starter-log4j2


And the following example shows one way to set up the starters in Gradle:
dependencies {
compile 'org.springframework.boot:spring-boot-starter-web'
compile 'org.springframework.boot:spring-boot-starter-log4j2'
}
configurations {
all {
exclude group: 'org.springframework.boot', module: 'spring-boot-starter-logging'
}
}

The Log4j starters gather together the dependencies for common logging requirements (such as having Tomcat use
java.util.logging but configuring the output using Log4j 2). See the Actuator Log4j 2 samples for more detail and to see it in
action.

To ensure that debug logging performed using java.util.logging is routed into Log4j 2, configure its JDK logging adapter by
setting the java.util.logging.manager system property to org.apache.logging.log4j.jul.LogManager .

83.2.1 Use YAML or JSON to Configure Log4j 2
In addition to its default XML configuration format, Log4j 2 also supports YAML and JSON configuration files. To configure Log4j 2 to use an
alternative configuration file format, add the appropriate dependencies to the classpath and name your configuration files to match your chosen file
format, as shown in the following example:
Format

Dependencies

File names

YAML

com.fasterxml.jackson.core:jackson-databind

log4j2.yaml

com.fasterxml.jackson.dataformat:jackson-dataformat-yaml

log4j2.yml

com.fasterxml.jackson.core:jackson-databind

log4j2.json

JSON

log4j2.jsn

84. Data Access
Spring Boot includes a number of starters for working with data sources. This section answers questions related to doing so.

84.1 Configure a Custom DataSource
To configure your own DataSource , define a @Bean of that type in your configuration. Spring Boot reuses your DataSource anywhere one is
required, including database initialization. If you need to externalize some settings, you can bind your DataSource to the environment (see
“Section 24.8.1, “Third-party Configuration””).
The following example shows how to define a data source in a bean:
@Bean
@ConfigurationProperties(prefix="app.datasource")
public DataSource dataSource() {
return new FancyDataSource();
}

The following example shows how to define a data source by setting properties:

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app.datasource.url=jdbc:h2:mem:mydb
app.datasource.username=sa
app.datasource.pool-size=30

Assuming that your FancyDataSource has regular JavaBean properties for the URL, the username, and the pool size, these settings are bound
automatically before the DataSource is made available to other components. The regular database initialization also happens (so the relevant subset of spring.datasource.* can still be used with your custom configuration).
Spring Boot also provides a utility builder class, called DataSourceBuilder , that can be used to create one of the standard data sources (if it is on
the classpath). The builder can detect the one to use based on what’s available on the classpath. It also auto-detects the driver based on the JDBC
URL.
The following example shows how to create a data source by using a DataSourceBuilder :
@Bean
@ConfigurationProperties("app.datasource")
public DataSource dataSource() {
return DataSourceBuilder.create().build();
}

To run an app with that DataSource , all you need is the connection information. Pool-specific settings can also be provided. Check the
implementation that is going to be used at runtime for more details.
The following example shows how to define a JDBC data source by setting properties:
app.datasource.url=jdbc:mysql://localhost/test
app.datasource.username=dbuser
app.datasource.password=dbpass
app.datasource.pool-size=30

However, there is a catch. Because the actual type of the connection pool is not exposed, no keys are generated in the metadata for your custom
DataSource and no completion is available in your IDE (because the DataSource interface exposes no properties). Also, if you happen to have
Hikari on the classpath, this basic setup does not work, because Hikari has no url property (but does have a jdbcUrl property). In that case, you
must rewrite your configuration as follows:
app.datasource.jdbc-url=jdbc:mysql://localhost/test
app.datasource.username=dbuser
app.datasource.password=dbpass
app.datasource.maximum-pool-size=30

You can fix that by forcing the connection pool to use and return a dedicated implementation rather than DataSource . You cannot change the
implementation at runtime, but the list of options will be explicit.
The following example shows how create a HikariDataSource with DataSourceBuilder :
@Bean
@ConfigurationProperties("app.datasource")
public HikariDataSource dataSource() {
return DataSourceBuilder.create().type(HikariDataSource.class).build();
}

You can even go further by leveraging what DataSourceProperties does for you — that is, by providing a default embedded database with a
sensible username and password if no URL is provided. You can easily initialize a DataSourceBuilder from the state of any
DataSourceProperties object, so you could also inject the DataSource that Spring Boot creates automatically. However, that would split your
configuration into two namespaces: url , username , password , type , and driver on spring.datasource and the rest on your custom
namespace ( app.datasource ). To avoid that, you can redefine a custom DataSourceProperties on your custom namespace, as shown in the
following example:
@Bean
@Primary
@ConfigurationProperties("app.datasource")
public DataSourceProperties dataSourceProperties() {
return new DataSourceProperties();
}
@Bean

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@ConfigurationProperties("app.datasource.configuration")
public HikariDataSource dataSource(DataSourceProperties properties) {
return properties.initializeDataSourceBuilder().type(HikariDataSource.class)
.build();
}

This setup puts you in sync with what Spring Boot does for you by default, except that a dedicated connection pool is chosen (in code) and its
settings are exposed in the app.datasource.configuration sub namespace. Because DataSourceProperties is taking care of the
url / jdbcUrl translation for you, you can configure it as follows:
app.datasource.url=jdbc:mysql://localhost/test
app.datasource.username=dbuser
app.datasource.password=dbpass
app.datasource.configuration.maximum-pool-size=30

Spring Boot will expose Hikari-specific settings to spring.datasource.hikari . This example uses a more generic configuration
sub namespace as the example does not support multiple datasource implementations.

Because your custom configuration chooses to go with Hikari, app.datasource.type has no effect. In practice, the builder is
initialized with whatever value you might set there and then overridden by the call to .type() .

See “Section 30.1, “Configure a DataSource”” in the “Spring Boot features” section and the DataSourceAutoConfiguration class for more
details.

84.2 Configure Two DataSources
If you need to configure multiple data sources, you can apply the same tricks that are described in the previous section. You must, however, mark
one of the DataSource instances as @Primary , because various auto-configurations down the road expect to be able to get one by type.
If you create your own DataSource , the auto-configuration backs off. In the following example, we provide the exact same feature set as the autoconfiguration provides on the primary data source:
@Bean
@Primary
@ConfigurationProperties("app.datasource.first")
public DataSourceProperties firstDataSourceProperties() {
return new DataSourceProperties();
}
@Bean
@Primary
@ConfigurationProperties("app.datasource.first.configuration")
public HikariDataSource firstDataSource() {
return firstDataSourceProperties().initializeDataSourceBuilder()
.type(HikariDataSource.class).build();
}
@Bean
@ConfigurationProperties("app.datasource.second")
public BasicDataSource secondDataSource() {
return DataSourceBuilder.create().type(BasicDataSource.class).build();
}

firstDataSourceProperties has to be flagged as @Primary so that the database initializer feature uses your copy (if you use the
initializer).

Both data sources are also bound for advanced customizations. For instance, you could configure them as follows:
app.datasource.first.url=jdbc:mysql://localhost/first
app.datasource.first.username=dbuser

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app.datasource.first.password=dbpass
app.datasource.first.configuration.maximum-pool-size=30
app.datasource.second.url=jdbc:mysql://localhost/second
app.datasource.second.username=dbuser
app.datasource.second.password=dbpass
app.datasource.second.max-total=30

You can apply the same concept to the secondary DataSource as well, as shown in the following example:
@Bean
@Primary
@ConfigurationProperties("app.datasource.first")
public DataSourceProperties firstDataSourceProperties() {
return new DataSourceProperties();
}
@Bean
@Primary
@ConfigurationProperties("app.datasource.first.configuration")
public HikariDataSource firstDataSource() {
return firstDataSourceProperties().initializeDataSourceBuilder()
.type(HikariDataSource.class).build();
}
@Bean
@ConfigurationProperties("app.datasource.second")
public DataSourceProperties secondDataSourceProperties() {
return new DataSourceProperties();
}
@Bean
@ConfigurationProperties("app.datasource.second.configuration")
public BasicDataSource secondDataSource() {
return secondDataSourceProperties().initializeDataSourceBuilder()
.type(BasicDataSource.class).build();
}

The preceding example configures two data sources on custom namespaces with the same logic as Spring Boot would use in auto-configuration.
Note that each configuration sub namespace provides advanced settings based on the chosen implementation.

84.3 Use Spring Data Repositories
Spring Data can create implementations of @Repository interfaces of various flavors. Spring Boot handles all of that for you, as long as those
@Repositories are included in the same package (or a sub-package) of your @EnableAutoConfiguration class.
For many applications, all you need is to put the right Spring Data dependencies on your classpath (there is a spring-boot-starter-data-jpa
for JPA and a spring-boot-starter-data-mongodb for Mongodb) and create some repository interfaces to handle your @Entity objects.
Examples are in the JPA sample and the Mongodb sample.
Spring Boot tries to guess the location of your @Repository definitions, based on the @EnableAutoConfiguration it finds. To get more control,
use the @EnableJpaRepositories annotation (from Spring Data JPA).
For more about Spring Data, see the Spring Data project page.

84.4 Separate @Entity Definitions from Spring Configuration
Spring Boot tries to guess the location of your @Entity definitions, based on the @EnableAutoConfiguration it finds. To get more control, you
can use the @EntityScan annotation, as shown in the following example:
@Configuration
@EnableAutoConfiguration
@EntityScan(basePackageClasses=City.class)
public class Application {

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//...

}

84.5 Configure JPA Properties
Spring Data JPA already provides some vendor-independent configuration options (such as those for SQL logging), and Spring Boot exposes those
options and a few more for Hibernate as external configuration properties. Some of them are automatically detected according to the context so you
should not have to set them.
The spring.jpa.hibernate.ddl-auto is a special case, because, depending on runtime conditions, it has different defaults. If an embedded
database is used and no schema manager (such as Liquibase or Flyway) is handling the DataSource , it defaults to create-drop . In all other
cases, it defaults to none .
The dialect to use is also automatically detected based on the current DataSource , but you can set spring.jpa.database yourself if you want to
be explicit and bypass that check on startup.

Specifying a database leads to the configuration of a well-defined Hibernate dialect. Several databases have more than one
Dialect , and this may not suit your needs. In that case, you can either set spring.jpa.database to default to let Hibernate
figure things out or set the dialect by setting the spring.jpa.database-platform property.

The most common options to set are shown in the following example:
spring.jpa.hibernate.naming.physical-strategy=com.example.MyPhysicalNamingStrategy
spring.jpa.show-sql=true

In addition, all properties in spring.jpa.properties.* are passed through as normal JPA properties (with the prefix stripped) when the local
EntityManagerFactory is created.

If you need to apply advanced customization to Hibernate properties, consider registering a HibernatePropertiesCustomizer
bean that will be invoked prior to creating the EntityManagerFactory . This takes precedence to anything that is applied by the autoconfiguration.

84.6 Configure Hibernate Naming Strategy
Hibernate uses two different naming strategies to map names from the object model to the corresponding database names. The fully qualified class
name of the physical and the implicit strategy implementations can be configured by setting the
spring.jpa.hibernate.naming.physical-strategy and spring.jpa.hibernate.naming.implicit-strategy properties, respectively.
Alternatively, if ImplicitNamingStrategy or PhysicalNamingStrategy beans are available in the application context, Hibernate will be
automatically configured to use them.
By default, Spring Boot configures the physical naming strategy with SpringPhysicalNamingStrategy . This implementation provides the same
table structure as Hibernate 4: all dots are replaced by underscores and camel casing is replaced by underscores as well. By default, all table
names are generated in lower case, but it is possible to override that flag if your schema requires it.
For example, a TelephoneNumber entity is mapped to the telephone_number table.
If you prefer to use Hibernate 5’s default instead, set the following property:
spring.jpa.hibernate.naming.physical-strategy=org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl

Alternatively, you can configure the following bean:
@Bean
public PhysicalNamingStrategy physicalNamingStrategy() {
return new PhysicalNamingStrategyStandardImpl();
}

See HibernateJpaAutoConfiguration and JpaBaseConfiguration for more details.
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84.7 Configure Hibernate Second-Level Caching
Hibernate second-level cache can be configured for a range of cache providers. Rather than configuring Hibernate to lookup the cache provider
again, it is better to provide the one that is available in the context whenever possible.
If you’re using JCache, this is pretty easy. First, make sure that org.hibernate:hibernate-jcache is available on the classpath. Then, add a
HibernatePropertiesCustomizer bean as shown in the following example:
@Configuration
public class HibernateSecondLevelCacheExample {
@Bean
public HibernatePropertiesCustomizer hibernateSecondLevelCacheCustomizer(
JCacheCacheManager cacheManager) {
return (properties) -> properties.put(ConfigSettings.CACHE_MANAGER,
cacheManager.getCacheManager());
}
}

This customizer will configure Hibernate to use the same CacheManager as the one that the application uses. It is also possible to use separate
CacheManager instances. For details, refer to the Hibernate user guide.

84.8 Use Dependency Injection in Hibernate Components
By default, Spring Boot registers a BeanContainer implementation that uses the BeanFactory so that converters and entity listeners can use
regular dependency injection.
You can disable or tune this behaviour by registering a HibernatePropertiesCustomizer that removes or changes the
hibernate.resource.beans.container property.

84.9 Use a Custom EntityManagerFactory
To take full control of the configuration of the EntityManagerFactory , you need to add a @Bean named ‘entityManagerFactory’. Spring Boot autoconfiguration switches off its entity manager in the presence of a bean of that type.

84.10 Use Two EntityManagers
Even if the default EntityManagerFactory works fine, you need to define a new one. Otherwise, the presence of the second bean of that type
switches off the default. To make it easy to do, you can use the convenient EntityManagerBuilder provided by Spring Boot. Alternatively, you can
just the LocalContainerEntityManagerFactoryBean directly from Spring ORM, as shown in the following example:
// add two data sources configured as above
@Bean
public LocalContainerEntityManagerFactoryBean customerEntityManagerFactory(
EntityManagerFactoryBuilder builder) {
return builder
.dataSource(customerDataSource())
.packages(Customer.class)
.persistenceUnit("customers")
.build();
}
@Bean
public LocalContainerEntityManagerFactoryBean orderEntityManagerFactory(
EntityManagerFactoryBuilder builder) {
return builder
.dataSource(orderDataSource())
.packages(Order.class)
.persistenceUnit("orders")

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.build();

}

The configuration above almost works on its own. To complete the picture, you need to configure TransactionManagers for the two
EntityManagers as well. If you mark one of them as @Primary , it could be picked up by the default JpaTransactionManager in Spring Boot.
The other would have to be explicitly injected into a new instance. Alternatively, you might be able to use a JTA transaction manager that spans
both.
If you use Spring Data, you need to configure @EnableJpaRepositories accordingly, as shown in the following example:
@Configuration
@EnableJpaRepositories(basePackageClasses = Customer.class,
entityManagerFactoryRef = "customerEntityManagerFactory")
public class CustomerConfiguration {
...
}
@Configuration
@EnableJpaRepositories(basePackageClasses = Order.class,
entityManagerFactoryRef = "orderEntityManagerFactory")
public class OrderConfiguration {
...
}

84.11 Use a Traditional persistence.xml File
Spring Boot will not search for or use a META-INF/persistence.xml by default. If you prefer to use a traditional persistence.xml , you need to
define your own @Bean of type LocalEntityManagerFactoryBean (with an ID of ‘entityManagerFactory’) and set the persistence unit name there.
See JpaBaseConfiguration for the default settings.

84.12 Use Spring Data JPA and Mongo Repositories
Spring Data JPA and Spring Data Mongo can both automatically create Repository implementations for you. If they are both present on the
classpath, you might have to do some extra configuration to tell Spring Boot which repositories to create. The most explicit way to do that is to use
the standard Spring Data @EnableJpaRepositories and @EnableMongoRepositories annotations and provide the location of your
Repository interfaces.
There are also flags ( spring.data.*.repositories.enabled and spring.data.*.repositories.type ) that you can use to switch the autoconfigured repositories on and off in external configuration. Doing so is useful, for instance, in case you want to switch off the Mongo repositories
and still use the auto-configured MongoTemplate .
The same obstacle and the same features exist for other auto-configured Spring Data repository types (Elasticsearch, Solr, and others). To work
with them, change the names of the annotations and flags accordingly.

84.13 Customize Spring Data’s Web Support
Spring Data provides web support that simplifies the use of Spring Data repositories in a web application. Spring Boot provides properties in the
spring.data.web namespace for customizing its configuration. Note that if you are using Spring Data REST, you must use the properties in the
spring.data.rest namespace instead.

84.14 Expose Spring Data Repositories as REST Endpoint
Spring Data REST can expose the Repository implementations as REST endpoints for you, provided Spring MVC has been enabled for the
application.
Spring Boot exposes a set of useful properties (from the spring.data.rest namespace) that customize the RepositoryRestConfiguration . If
you need to provide additional customization, you should use a RepositoryRestConfigurer bean.

If you do not specify any order on your custom RepositoryRestConfigurer , it runs after the one Spring Boot uses internally. If you
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need to specify an order, make sure it is higher than 0.

84.15 Configure a Component that is Used by JPA
If you want to configure a component that JPA uses, then you need to ensure that the component is initialized before JPA. When the component is
auto-configured, Spring Boot takes care of this for you. For example, when Flyway is auto-configured, Hibernate is configured to depend upon
Flyway so that Flyway has a chance to initialize the database before Hibernate tries to use it.
If you are configuring a component yourself, you can use an EntityManagerFactoryDependsOnPostProcessor subclass as a convenient way of
setting up the necessary dependencies. For example, if you use Hibernate Search with Elasticsearch as its index manager, any
EntityManagerFactory beans must be configured to depend on the elasticsearchClient bean, as shown in the following example:
/**
* {@link EntityManagerFactoryDependsOnPostProcessor} that ensures that
* {@link EntityManagerFactory} beans depend on the {@code elasticsearchClient} bean.
*/
@Configuration
static class ElasticsearchJpaDependencyConfiguration
extends EntityManagerFactoryDependsOnPostProcessor {
ElasticsearchJpaDependencyConfiguration() {
super("elasticsearchClient");
}
}

84.16 Configure jOOQ with Two DataSources
If you need to use jOOQ with multiple data sources, you should create your own DSLContext for each one. Refer to JooqAutoConfiguration for
more details.

In particular, JooqExceptionTranslator and SpringTransactionProvider can be reused to provide similar features to what the
auto-configuration does with a single DataSource .

85. Database Initialization
An SQL database can be initialized in different ways depending on what your stack is. Of course, you can also do it manually, provided the database
is a separate process.

85.1 Initialize a Database Using JPA
JPA has features for DDL generation, and these can be set up to run on startup against the database. This is controlled through two external
properties:
spring.jpa.generate-ddl (boolean) switches the feature on and off and is vendor independent.
spring.jpa.hibernate.ddl-auto (enum) is a Hibernate feature that controls the behavior in a more fine-grained way. This feature is
described in more detail later in this guide.

85.2 Initialize a Database Using Hibernate
You can set spring.jpa.hibernate.ddl-auto explicitly and the standard Hibernate property values are none , validate , update , create ,
and create-drop . Spring Boot chooses a default value for you based on whether it thinks your database is embedded. It defaults to
create-drop if no schema manager has been detected or none in all other cases. An embedded database is detected by looking at the
Connection type. hsqldb , h2 , and derby are embedded, and others are not. Be careful when switching from in-memory to a ‘real’ database
that you do not make assumptions about the existence of the tables and data in the new platform. You either have to set ddl-auto explicitly or use
one of the other mechanisms to initialize the database.

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You can output the schema creation by enabling the org.hibernate.SQL logger. This is done for you automatically if you enable the
debug mode.

In addition, a file named import.sql in the root of the classpath is executed on startup if Hibernate creates the schema from scratch (that is, if the
ddl-auto property is set to create or create-drop ). This can be useful for demos and for testing if you are careful but is probably not
something you want to be on the classpath in production. It is a Hibernate feature (and has nothing to do with Spring).

85.3 Initialize a Database
Spring Boot can automatically create the schema (DDL scripts) of your DataSource and initialize it (DML scripts). It loads SQL from the standard
root classpath locations: schema.sql and data.sql , respectively. In addition, Spring Boot processes the schema-${platform}.sql and
data-${platform}.sql files (if present), where platform is the value of spring.datasource.platform . This allows you to switch to
database-specific scripts if necessary. For example, you might choose to set it to the vendor name of the database ( hsqldb , h2 , oracle , mysql ,
postgresql , and so on).

Spring Boot automatically creates the schema of an embedded DataSource . This behaviour can be customized by using the
spring.datasource.initialization-mode property. For instance, if you want to always initialize the DataSource regardless of
its type:
spring.datasource.initialization-mode=always

By default, Spring Boot enables the fail-fast feature of the Spring JDBC initializer. This means that, if the scripts cause exceptions, the application
fails to start. You can tune that behavior by setting spring.datasource.continue-on-error .

In a JPA-based app, you can choose to let Hibernate create the schema or use schema.sql , but you cannot do both. Make sure to
disable spring.jpa.hibernate.ddl-auto if you use schema.sql .

85.4 Initialize a Spring Batch Database
If you use Spring Batch, it comes pre-packaged with SQL initialization scripts for most popular database platforms. Spring Boot can detect your
database type and execute those scripts on startup. If you use an embedded database, this happens by default. You can also enable it for any
database type, as shown in the following example:
spring.batch.initialize-schema=always

You can also switch off the initialization explicitly by setting spring.batch.initialize-schema=never .

85.5 Use a Higher-level Database Migration Tool
Spring Boot supports two higher-level migration tools: Flyway and Liquibase.

85.5.1 Execute Flyway Database Migrations on Startup
To automatically run Flyway database migrations on startup, add the org.flywaydb:flyway-core to your classpath.
The migrations are scripts in the form V__.sql (with  an underscore-separated version, such as ‘1’ or ‘2_1’). By
default, they are in a folder called classpath:db/migration , but you can modify that location by setting spring.flyway.locations . This is a
comma-separated list of one or more classpath: or filesystem: locations. For example, the following configuration would search for scripts in
both the default classpath location and the /opt/migration directory:
spring.flyway.locations=classpath:db/migration,filesystem:/opt/migration

You can also add a special {vendor} placeholder to use vendor-specific scripts. Assume the following:
spring.flyway.locations=classpath:db/migration/{vendor}

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Rather than using db/migration , the preceding configuration sets the folder to use according to the type of the database (such as
db/migration/mysql for MySQL). The list of supported databases is available in DatabaseDriver .
FlywayProperties provides most of Flyway’s settings and a small set of additional properties that can be used to disable the migrations or switch
off the location checking. If you need more control over the configuration, consider registering a FlywayConfigurationCustomizer bean.
Spring Boot calls Flyway.migrate() to perform the database migration. If you would like more control, provide a @Bean that implements
FlywayMigrationStrategy .
Flyway supports SQL and Java callbacks. To use SQL-based callbacks, place the callback scripts in the classpath:db/migration folder. To use
Java-based callbacks, create one or more beans that implement Callback . Any such beans are automatically registered with Flyway . They can
be ordered by using @Order or by implementing Ordered . Beans that implement the deprecated FlywayCallback interface can also be
detected, however they cannot be used alongside Callback beans.
By default, Flyway autowires the ( @Primary ) DataSource in your context and uses that for migrations. If you like to use a different DataSource ,
you can create one and mark its @Bean as @FlywayDataSource . If you do so and want two data sources, remember to create another one and
mark it as @Primary . Alternatively, you can use Flyway’s native DataSource by setting spring.flyway.[url,user,password] in external
properties. Setting either spring.flyway.url or spring.flyway.user is sufficient to cause Flyway to use its own DataSource . If any of the
three properties has not be set, the value of its equivalent spring.datasource property will be used.
There is a Flyway sample so that you can see how to set things up.
You can also use Flyway to provide data for specific scenarios. For example, you can place test-specific migrations in src/test/resources and
they are run only when your application starts for testing. Also, you can use profile-specific configuration to customize spring.flyway.locations
so that certain migrations run only when a particular profile is active. For example, in application-dev.properties , you might specify the
following setting:
spring.flyway.locations=classpath:/db/migration,classpath:/dev/db/migration

With that setup, migrations in dev/db/migration run only when the dev profile is active.

85.5.2 Execute Liquibase Database Migrations on Startup
To automatically run Liquibase database migrations on startup, add the org.liquibase:liquibase-core to your classpath.
By default, the master change log is read from db/changelog/db.changelog-master.yaml , but you can change the location by setting
spring.liquibase.change-log . In addition to YAML, Liquibase also supports JSON, XML, and SQL change log formats.
By default, Liquibase autowires the ( @Primary ) DataSource in your context and uses that for migrations. If you need to use a different
DataSource , you can create one and mark its @Bean as @LiquibaseDataSource . If you do so and you want two data sources, remember to
create another one and mark it as @Primary . Alternatively, you can use Liquibase’s native DataSource by setting
spring.liquibase.[url,user,password] in external properties. Setting either spring.liquibase.url or spring.liquibase.user is
sufficient to cause Liquibase to use its own DataSource . If any of the three properties has not be set, the value of its equivalent
spring.datasource property will be used.
See LiquibaseProperties for details about available settings such as contexts, the default schema, and others.
There is a Liquibase sample so that you can see how to set things up.

86. Messaging
Spring Boot offers a number of starters that include messaging. This section answers questions that arise from using messaging with Spring Boot.

86.1 Disable Transacted JMS Session
If your JMS broker does not support transacted sessions, you have to disable the support of transactions altogether. If you create your own
JmsListenerContainerFactory , there is nothing to do, since, by default it cannot be transacted. If you want to use the
DefaultJmsListenerContainerFactoryConfigurer to reuse Spring Boot’s default, you can disable transacted sessions, as follows:
@Bean
public DefaultJmsListenerContainerFactory jmsListenerContainerFactory(
ConnectionFactory connectionFactory,

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DefaultJmsListenerContainerFactoryConfigurer configurer) {
DefaultJmsListenerContainerFactory listenerFactory =
new DefaultJmsListenerContainerFactory();
configurer.configure(listenerFactory, connectionFactory);
listenerFactory.setTransactionManager(null);
listenerFactory.setSessionTransacted(false);
return listenerFactory;

}

The preceding example overrides the default factory, and it should be applied to any other factory that your application defines, if any.

87. Batch Applications
This section answers questions that arise from using Spring Batch with Spring Boot.

By default, batch applications require a DataSource to store job details. If you want to deviate from that, you need to implement
BatchConfigurer . See The Javadoc of @EnableBatchProcessing for more details.

For more about Spring Batch, see the Spring Batch project page.

87.1 Execute Spring Batch Jobs on Startup
Spring Batch auto-configuration is enabled by adding @EnableBatchProcessing (from Spring Batch) somewhere in your context.
By default, it executes all Jobs in the application context on startup (see JobLauncherCommandLineRunner for details). You can narrow down to a
specific job or jobs by specifying spring.batch.job.names (which takes a comma-separated list of job name patterns).

Unlike command line option arguments that set properties in the Environment (i.e. by starting with -- , such as
--my-property=value ), job parameters have to be specified on the command line without dashes (e.g. jobParam=value ).

If the application context includes a JobRegistry , the jobs in spring.batch.job.names are looked up in the registry instead of being autowired
from the context. This is a common pattern with more complex systems, where multiple jobs are defined in child contexts and registered centrally.
See BatchAutoConfiguration and @EnableBatchProcessing for more details.

88. Actuator
Spring Boot includes the Spring Boot Actuator. This section answers questions that often arise from its use.

88.1 Change the HTTP Port or Address of the Actuator Endpoints
In a standalone application, the Actuator HTTP port defaults to the same as the main HTTP port. To make the application listen on a different port,
set the external property: management.server.port . To listen on a completely different network address (such as when you have an internal
network for management and an external one for user applications), you can also set management.server.address to a valid IP address to which
the server is able to bind.
For more detail, see the ManagementServerProperties source code and “Section 54.2, “Customizing the Management Server Port”” in the
“Production-ready features” section.

88.2 Customize the ‘whitelabel’ Error Page
Spring Boot installs a ‘whitelabel’ error page that you see in a browser client if you encounter a server error (machine clients consuming JSON and
other media types should see a sensible response with the right error code).

Set server.error.whitelabel.enabled=false to switch the default error page off. Doing so restores the default of the servlet
container that you are using. Note that Spring Boot still tries to resolve the error view, so you should probably add your own error page
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rather than disabling it completely.

Overriding the error page with your own depends on the templating technology that you use. For example, if you use Thymeleaf, you can add an
error.html template. If you use FreeMarker, you can add an error.ftl template. In general, you need a View that resolves with a name of
error or a @Controller that handles the /error path. Unless you replaced some of the default configuration, you should find a
BeanNameViewResolver in your ApplicationContext , so a @Bean named error would be a simple way of doing that. See
ErrorMvcAutoConfiguration for more options.
See also the section on “Error Handling” for details of how to register handlers in the servlet container.

88.3 Sanitize sensible values
Information returned by the env and configprops endpoints can be somewhat sensitive so keys matching a certain pattern are sanitized by
default (i.e. their values are replaced by ****** ).
Spring Boot uses sensible defaults for such keys: for instance, any key ending with the word "password", "secret", "key" or "token" is sanitized. It is
also possible to use a regular expression instead, such as *credentials.* to sanitize any key that holds the word credentials as part of the
key.
The patterns to use can be customized using the management.endpoint.env.keys-to-sanitize and
management.endpoint.configprops.keys-to-sanitize respectively.

89. Security
This section addresses questions about security when working with Spring Boot, including questions that arise from using Spring Security with
Spring Boot.
For more about Spring Security, see the Spring Security project page.

89.1 Switch off the Spring Boot Security Configuration
If you define a @Configuration with a WebSecurityConfigurerAdapter in your application, it switches off the default webapp security settings
in Spring Boot.

89.2 Change the UserDetailsService and Add User Accounts
If you provide a @Bean of type AuthenticationManager , AuthenticationProvider , or UserDetailsService , the default @Bean for
InMemoryUserDetailsManager is not created, so you have the full feature set of Spring Security available (such as various authentication
options).
The easiest way to add user accounts is to provide your own UserDetailsService bean.

89.3 Enable HTTPS When Running behind a Proxy Server
Ensuring that all your main endpoints are only available over HTTPS is an important chore for any application. If you use Tomcat as a servlet
container, then Spring Boot adds Tomcat’s own RemoteIpValve automatically if it detects some environment settings, and you should be able to
rely on the HttpServletRequest to report whether it is secure or not (even downstream of a proxy server that handles the real SSL termination).
The standard behavior is determined by the presence or absence of certain request headers ( x-forwarded-for and x-forwarded-proto ),
whose names are conventional, so it should work with most front-end proxies. You can switch on the valve by adding some entries to
application.properties , as shown in the following example:
server.tomcat.remote-ip-header=x-forwarded-for
server.tomcat.protocol-header=x-forwarded-proto

(The presence of either of those properties switches on the valve. Alternatively, you can add the RemoteIpValve by adding a
TomcatServletWebServerFactory bean.)

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To configure Spring Security to require a secure channel for all (or some) requests, consider adding your own WebSecurityConfigurerAdapter
that adds the following HttpSecurity configuration:
@Configuration
public class SslWebSecurityConfigurerAdapter extends WebSecurityConfigurerAdapter {
@Override
protected void configure(HttpSecurity http) throws Exception {
// Customize the application security
http.requiresChannel().anyRequest().requiresSecure();
}
}

90. Hot Swapping
Spring Boot supports hot swapping. This section answers questions about how it works.

90.1 Reload Static Content
There are several options for hot reloading. The recommended approach is to use spring-boot-devtools , as it provides additional developmenttime features, such as support for fast application restarts and LiveReload as well as sensible development-time configuration (such as template
caching). Devtools works by monitoring the classpath for changes. This means that static resource changes must be "built" for the change to take
affect. By default, this happens automatically in Eclipse when you save your changes. In IntelliJ IDEA, the Make Project command triggers the
necessary build. Due to the default restart exclusions, changes to static resources do not trigger a restart of your application. They do, however,
trigger a live reload.
Alternatively, running in an IDE (especially with debugging on) is a good way to do development (all modern IDEs allow reloading of static resources
and usually also allow hot-swapping of Java class changes).
Finally, the Maven and Gradle plugins can be configured (see the addResources property) to support running from the command line with
reloading of static files directly from source. You can use that with an external css/js compiler process if you are writing that code with higher-level
tools.

90.2 Reload Templates without Restarting the Container
Most of the templating technologies supported by Spring Boot include a configuration option to disable caching (described later in this document). If
you use the spring-boot-devtools module, these properties are automatically configured for you at development time.

90.2.1 Thymeleaf Templates
If you use Thymeleaf, set spring.thymeleaf.cache to false . See ThymeleafAutoConfiguration for other Thymeleaf customization options.

90.2.2 FreeMarker Templates
If you use FreeMarker, set spring.freemarker.cache to false . See FreeMarkerAutoConfiguration for other FreeMarker customization
options.

90.2.3 Groovy Templates
If you use Groovy templates, set spring.groovy.template.cache to false . See GroovyTemplateAutoConfiguration for other Groovy
customization options.

90.3 Fast Application Restarts
The spring-boot-devtools module includes support for automatic application restarts. While not as fast as technologies such as JRebel it is
usually significantly faster than a “cold start”. You should probably give it a try before investigating some of the more complex reload options
discussed later in this document.
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For more details, see the Chapter 20, Developer Tools section.

90.4 Reload Java Classes without Restarting the Container
Many modern IDEs (Eclipse, IDEA, and others) support hot swapping of bytecode. Consequently, if you make a change that does not affect class or
method signatures, it should reload cleanly with no side effects.

91. Build
Spring Boot includes build plugins for Maven and Gradle. This section answers common questions about these plugins.

91.1 Generate Build Information
Both the Maven plugin and the Gradle plugin allow generating build information containing the coordinates, name, and version of the project. The
plugins can also be configured to add additional properties through configuration. When such a file is present, Spring Boot auto-configures a
BuildProperties bean.
To generate build information with Maven, add an execution for the build-info goal, as shown in the following example:



org.springframework.boot
spring-boot-maven-plugin
2.1.2.BUILD-SNAPSHOT



build-info







See the Spring Boot Maven Plugin documentation for more details.

The following example does the same with Gradle:
springBoot {
buildInfo()
}

See the Spring Boot Gradle Plugin documentation for more details.

91.2 Generate Git Information
Both Maven and Gradle allow generating a git.properties file containing information about the state of your git source code repository when
the project was built.
For Maven users, the spring-boot-starter-parent POM includes a pre-configured plugin to generate a git.properties file. To use it, add
the following declaration to your POM:



pl.project13.maven

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git-commit-id-plugin




Gradle users can achieve the same result by using the gradle-git-properties plugin, as shown in the following example:
plugins {
id "com.gorylenko.gradle-git-properties" version "1.5.1"
}

The commit time in git.properties is expected to match the following format: yyyy-MM-dd’T’HH:mm:ssZ . This is the default
format for both plugins listed above. Using this format lets the time be parsed into a Date and its format, when serialized to JSON, to
be controlled by Jackson’s date serialization configuration settings.

91.3 Customize Dependency Versions
If you use a Maven build that inherits directly or indirectly from spring-boot-dependencies (for instance, spring-boot-starter-parent ) but
you want to override a specific third-party dependency, you can add appropriate  elements. Browse the
spring-boot-dependencies POM for a complete list of properties. For example, to pick a different slf4j version, you would add the following
property:

1.7.5


Doing so only works if your Maven project inherits (directly or indirectly) from spring-boot-dependencies . If you have added
spring-boot-dependencies in your own dependencyManagement section with import , you have to redefine
the artifact yourself instead of overriding the property.

Each Spring Boot release is designed and tested against this specific set of third-party dependencies. Overriding versions may cause
compatibility issues.

To override dependency versions in Gradle, see this section of the Gradle plugin’s documentation.

91.4 Create an Executable JAR with Maven
The spring-boot-maven-plugin can be used to create an executable “fat” JAR. If you use the spring-boot-starter-parent POM, you can
declare the plugin and your jars are repackaged as follows:



org.springframework.boot
spring-boot-maven-plugin




If you do not use the parent POM, you can still use the plugin. However, you must additionally add an  section, as follows:



org.springframework.boot
spring-boot-maven-plugin
2.1.2.BUILD-SNAPSHOT



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repackage








See the plugin documentation for full usage details.

91.5 Use a Spring Boot Application as a Dependency
Like a war file, a Spring Boot application is not intended to be used as a dependency. If your application contains classes that you want to share with
other projects, the recommended approach is to move that code into a separate module. The separate module can then be depended upon by your
application and other projects.
If you cannot rearrange your code as recommended above, Spring Boot’s Maven and Gradle plugins must be configured to produce a separate
artifact that is suitable for use as a dependency. The executable archive cannot be used as a dependency as the executable jar format packages
application classes in BOOT-INF/classes . This means that they cannot be found when the executable jar is used as a dependency.
To produce the two artifacts, one that can be used as a dependency and one that is executable, a classifier must be specified. This classifier is
applied to the name of the executable archive, leaving the default archive for use as a dependency.
To configure a classifier of exec in Maven, you can use the following configuration:



org.springframework.boot
spring-boot-maven-plugin

exec





91.6 Extract Specific Libraries When an Executable Jar Runs
Most nested libraries in an executable jar do not need to be unpacked in order to run. However, certain libraries can have problems. For example,
JRuby includes its own nested jar support, which assumes that the jruby-complete.jar is always directly available as a file in its own right.
To deal with any problematic libraries, you can flag that specific nested jars should be automatically unpacked when the executable jar first runs.
Such nested jars are written beneath the temporary directory identified by the java.io.tmpdir system property.

Care should be taken to ensure that your operating system is configured so that it will not delete the jars that have been unpacked to
the temporary directory while the application is still running.

For example, to indicate that JRuby should be flagged for unpacking by using the Maven Plugin, you would add the following configuration:



org.springframework.boot
spring-boot-maven-plugin



org.jruby
jruby-complete




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91.7 Create a Non-executable JAR with Exclusions
Often, if you have an executable and a non-executable jar as two separate build products, the executable version has additional configuration files
that are not needed in a library jar. For example, the application.yml configuration file might by excluded from the non-executable JAR.
In Maven, the executable jar must be the main artifact and you can add a classified jar for the library, as follows:



org.springframework.boot
spring-boot-maven-plugin


maven-jar-plugin


lib
package

jar


lib

application.yml








91.8 Remote Debug a Spring Boot Application Started with Maven
To attach a remote debugger to a Spring Boot application that was started with Maven, you can use the jvmArguments property of the maven
plugin.
See this example for more details.

91.9 Build an Executable Archive from Ant without Using spring-boot-antlib
To build with Ant, you need to grab dependencies, compile, and then create a jar or war archive. To make it executable, you can either use the
spring-boot-antlib module or you can follow these instructions:
1. If you are building a jar, package the application’s classes and resources in a nested BOOT-INF/classes directory. If you are building a war,
package the application’s classes in a nested WEB-INF/classes directory as usual.
2. Add the runtime dependencies in a nested BOOT-INF/lib directory for a jar or WEB-INF/lib for a war. Remember not to compress the
entries in the archive.
3. Add the provided (embedded container) dependencies in a nested BOOT-INF/lib directory for a jar or WEB-INF/lib-provided for a war.
Remember not to compress the entries in the archive.
4. Add the spring-boot-loader classes at the root of the archive (so that the Main-Class is available).
5. Use the appropriate launcher (such as JarLauncher for a jar file) as a Main-Class attribute in the manifest and specify the other properties it
needs as manifest entries — principally, by setting a Start-Class property.
The following example shows how to build an executable archive with Ant:


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The Ant Sample has a build.xml file with a manual task that should work if you run it with the following command:
$ ant -lib  clean manual

Then you can run the application with the following command:
$ java -jar target/*.jar

92. Traditional Deployment
Spring Boot supports traditional deployment as well as more modern forms of deployment. This section answers common questions about traditional
deployment.

92.1 Create a Deployable War File
Because Spring WebFlux does not strictly depend on the Servlet API and applications are deployed by default on an embedded
Reactor Netty server, War deployment is not supported for WebFlux applications.

The first step in producing a deployable war file is to provide a SpringBootServletInitializer subclass and override its configure method.
Doing so makes use of Spring Framework’s Servlet 3.0 support and lets you configure your application when it is launched by the servlet container.
Typically, you should update your application’s main class to extend SpringBootServletInitializer , as shown in the following example:
@SpringBootApplication
public class Application extends SpringBootServletInitializer {
@Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
return application.sources(Application.class);
}
public static void main(String[] args) throws Exception {
SpringApplication.run(Application.class, args);
}
}

The next step is to update your build configuration such that your project produces a war file rather than a jar file. If you use Maven and
spring-boot-starter-parent (which configures Maven’s war plugin for you), all you need to do is to modify pom.xml to change the packaging
to war, as follows:
war

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If you use Gradle, you need to modify build.gradle to apply the war plugin to the project, as follows:
apply plugin: 'war'

The final step in the process is to ensure that the embedded servlet container does not interfere with the servlet container to which the war file is
deployed. To do so, you need to mark the embedded servlet container dependency as being provided.
If you use Maven, the following example marks the servlet container (Tomcat, in this case) as being provided:



org.springframework.boot
spring-boot-starter-tomcat
provided




If you use Gradle, the following example marks the servlet container (Tomcat, in this case) as being provided:
dependencies {
// …
providedRuntime 'org.springframework.boot:spring-boot-starter-tomcat'
// …
}

providedRuntime is preferred to Gradle’s compileOnly configuration. Among other limitations, compileOnly dependencies are
not on the test classpath, so any web-based integration tests fail.

If you use the Spring Boot build tools, marking the embedded servlet container dependency as provided produces an executable war file with the
provided dependencies packaged in a lib-provided directory. This means that, in addition to being deployable to a servlet container, you can
also run your application by using java -jar on the command line.

Take a look at Spring Boot’s sample applications for a Maven-based example of the previously described configuration.

92.2 Convert an Existing Application to Spring Boot
For a non-web application, it should be easy to convert an existing Spring application to a Spring Boot application. To do so, throw away the code
that creates your ApplicationContext and replace it with calls to SpringApplication or SpringApplicationBuilder . Spring MVC web
applications are generally amenable to first creating a deployable war application and then migrating it later to an executable war or jar. See the
Getting Started Guide on Converting a jar to a war.
To create a deployable war by extending SpringBootServletInitializer (for example, in a class called Application ) and adding the Spring
Boot @SpringBootApplication annotation, use code similar to that shown in the following example:
@SpringBootApplication
public class Application extends SpringBootServletInitializer {
@Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
// Customize the application or call application.sources(...) to add sources
// Since our example is itself a @Configuration class (via @SpringBootApplication)
// we actually don't need to override this method.
return application;
}
}

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Remember that, whatever you put in the sources is merely a Spring ApplicationContext . Normally, anything that already works should work
here. There might be some beans you can remove later and let Spring Boot provide its own defaults for them, but it should be possible to get
something working before you need to do that.
Static resources can be moved to /public (or /static or /resources or /META-INF/resources ) in the classpath root. The same applies to
messages.properties (which Spring Boot automatically detects in the root of the classpath).
Vanilla usage of Spring DispatcherServlet and Spring Security should require no further changes. If you have other features in your application
(for instance, using other servlets or filters), you may need to add some configuration to your Application context, by replacing those elements
from the web.xml , as follows:
A @Bean of type Servlet or ServletRegistrationBean installs that bean in the container as if it were a  and
 in web.xml .
A @Bean of type Filter or FilterRegistrationBean behaves similarly (as a  and  ).
An ApplicationContext in an XML file can be added through an @ImportResource in your Application . Alternatively, simple cases
where annotation configuration is heavily used already can be recreated in a few lines as @Bean definitions.
Once the war file is working, you can make it executable by adding a main method to your Application , as shown in the following example:
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}

If you intend to start your application as a war or as an executable application, you need to share the customizations of the builder in a
method that is both available to the SpringBootServletInitializer callback and in the main method in a class similar to the
following:
@SpringBootApplication
public class Application extends SpringBootServletInitializer {
@Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
return configureApplication(builder);
}
public static void main(String[] args) {
configureApplication(new SpringApplicationBuilder()).run(args);
}
private static SpringApplicationBuilder configureApplication(SpringApplicationBuilder builder) {
return builder.sources(Application.class).bannerMode(Banner.Mode.OFF);
}
}

Applications can fall into more than one category:
Servlet 3.0+ applications with no web.xml .
Applications with a web.xml .
Applications with a context hierarchy.
Applications without a context hierarchy.
All of these should be amenable to translation, but each might require slightly different techniques.
Servlet 3.0+ applications might translate pretty easily if they already use the Spring Servlet 3.0+ initializer support classes. Normally, all the code
from an existing WebApplicationInitializer can be moved into a SpringBootServletInitializer . If your existing application has more
than one ApplicationContext (for example, if it uses AbstractDispatcherServletInitializer ) then you might be able to combine all your
context sources into a single SpringApplication . The main complication you might encounter is if combining does not work and you need to
maintain the context hierarchy. See the entry on building a hierarchy for examples. An existing parent context that contains web-specific features
usually needs to be broken up so that all the ServletContextAware components are in the child context.
Applications that are not already Spring applications might be convertible to Spring Boot applications, and the previously mentioned guidance may
help. However, you may yet encounter problems. In that case, we suggest asking questions on Stack Overflow with a tag of spring-boot .

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92.3 Deploying a WAR to WebLogic
To deploy a Spring Boot application to WebLogic, you must ensure that your servlet initializer directly implements WebApplicationInitializer
(even if you extend from a base class that already implements it).
A typical initializer for WebLogic should resemble the following example:
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
import org.springframework.web.WebApplicationInitializer;
@SpringBootApplication
public class MyApplication extends SpringBootServletInitializer implements WebApplicationInitializer {
}

If you use Logback, you also need to tell WebLogic to prefer the packaged version rather than the version that was pre-installed with the server. You
can do so by adding a WEB-INF/weblogic.xml file with the following contents:




org.slf4j




92.4 Use Jedis Instead of Lettuce
By default, the Spring Boot starter ( spring-boot-starter-data-redis ) uses Lettuce. You need to exclude that dependency and include the
Jedis one instead. Spring Boot manages these dependencies to help make this process as easy as possible.
The following example shows how to do so in Maven:

org.springframework.boot
spring-boot-starter-data-redis


io.lettuce
lettuce-core




redis.clients
jedis


The following example shows how to do so in Gradle:
configurations {
compile.exclude module: "lettuce"
}
dependencies {
compile("redis.clients:jedis")
// ...
}

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Part X. Appendices
Appendix A. Common application properties
Various properties can be specified inside your application.properties file, inside your application.yml file, or as command line switches.
This appendix provides a list of common Spring Boot properties and references to the underlying classes that consume them.

Spring Boot provides various conversion mechanism with advanced value formatting, make sure to review the properties conversion
section.

Property contributions can come from additional jar files on your classpath, so you should not consider this an exhaustive list. Also,
you can define your own properties.

This sample file is meant as a guide only. Do not copy and paste the entire content into your application. Rather, pick only the
properties that you need.

#
#
#
#
#
#

===================================================================
COMMON SPRING BOOT PROPERTIES
This sample file is provided as a guideline. Do NOT copy it in its
entirety to your own application.
^^^
===================================================================

# ---------------------------------------# CORE PROPERTIES
# ---------------------------------------debug=false # Enable debug logs.
trace=false # Enable trace logs.
# LOGGING
logging.config= # Location of the logging configuration file. For instance, `classpath:logback.xml` for Logback.
logging.exception-conversion-word=%wEx # Conversion word used when logging exceptions.
logging.file= # Log file name (for instance, `myapp.log`). Names can be an exact location or relative to the current directory
logging.file.max-history=0 # Maximum of archive log files to keep. Only supported with the default logback setup.
logging.file.max-size=10MB # Maximum log file size. Only supported with the default logback setup.
logging.group.*= # Log groups to quickly change multiple loggers at the same time. For instance, `logging.level.db=org.hiberna
logging.level.*= # Log levels severity mapping. For instance, `logging.level.org.springframework=DEBUG`.
logging.path= # Location of the log file. For instance, `/var/log`.
logging.pattern.console= # Appender pattern for output to the console. Supported only with the default Logback setup.
logging.pattern.dateformat=yyyy-MM-dd HH:mm:ss.SSS # Appender pattern for log date format. Supported only with the default Log
logging.pattern.file= # Appender pattern for output to a file. Supported only with the default Logback setup.
logging.pattern.level=%5p # Appender pattern for log level. Supported only with the default Logback setup.
logging.register-shutdown-hook=false # Register a shutdown hook for the logging system when it is initialized.
# AOP
spring.aop.auto=true # Add @EnableAspectJAutoProxy.
spring.aop.proxy-target-class=true # Whether subclass-based (CGLIB) proxies are to be created (true), as opposed to standard J
# IDENTITY (ContextIdApplicationContextInitializer)
spring.application.name= # Application name.
# ADMIN (SpringApplicationAdminJmxAutoConfiguration)
spring.application.admin.enabled=false # Whether to enable admin features for the application.
spring.application.admin.jmx-name=org.springframework.boot:type=Admin,name=SpringApplication # JMX name of the application adm
# AUTO-CONFIGURATION
spring.autoconfigure.exclude= # Auto-configuration classes to exclude.
# BANNER

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spring.banner.charset=UTF-8 # Banner file encoding.
spring.banner.location=classpath:banner.txt # Banner text resource location.
spring.banner.image.location=classpath:banner.gif # Banner image file location (jpg or png can also be used).
spring.banner.image.width=76 # Width of the banner image in chars.
spring.banner.image.height= # Height of the banner image in chars (default based on image height).
spring.banner.image.margin=2 # Left hand image margin in chars.
spring.banner.image.invert=false # Whether images should be inverted for dark terminal themes.
# SPRING CORE
spring.beaninfo.ignore=true # Whether to skip search of BeanInfo classes.
# SPRING CACHE (CacheProperties)
spring.cache.cache-names= # Comma-separated list of cache names to create if supported by the underlying cache manager.
spring.cache.caffeine.spec= # The spec to use to create caches. See CaffeineSpec for more details on the spec format.
spring.cache.couchbase.expiration= # Entry expiration. By default the entries never expire. Note that this value is ultimately
spring.cache.ehcache.config= # The location of the configuration file to use to initialize EhCache.
spring.cache.infinispan.config= # The location of the configuration file to use to initialize Infinispan.
spring.cache.jcache.config= # The location of the configuration file to use to initialize the cache manager.
spring.cache.jcache.provider= # Fully qualified name of the CachingProvider implementation to use to retrieve the JSR-107 comp
spring.cache.redis.cache-null-values=true # Allow caching null values.
spring.cache.redis.key-prefix= # Key prefix.
spring.cache.redis.time-to-live= # Entry expiration. By default the entries never expire.
spring.cache.redis.use-key-prefix=true # Whether to use the key prefix when writing to Redis.
spring.cache.type= # Cache type. By default, auto-detected according to the environment.
# SPRING CONFIG - using environment property only (ConfigFileApplicationListener)
spring.config.additional-location= # Config file locations used in addition to the defaults.
spring.config.location= # Config file locations that replace the defaults.
spring.config.name=application # Config file name.
# HAZELCAST (HazelcastProperties)
spring.hazelcast.config= # The location of the configuration file to use to initialize Hazelcast.
# PROJECT INFORMATION (ProjectInfoProperties)
spring.info.build.encoding=UTF-8 # File encoding.
spring.info.build.location=classpath:META-INF/build-info.properties # Location of the generated build-info.properties file.
spring.info.git.encoding=UTF-8 # File encoding.
spring.info.git.location=classpath:git.properties # Location of the generated git.properties file.
# JMX
spring.jmx.default-domain= # JMX domain name.
spring.jmx.enabled=true # Expose management beans to the JMX domain.
spring.jmx.server=mbeanServer # MBeanServer bean name.
spring.jmx.unique-names=false # Whether unique runtime object names should be ensured.
# Email (MailProperties)
spring.mail.default-encoding=UTF-8 # Default MimeMessage encoding.
spring.mail.host= # SMTP server host. For instance, `smtp.example.com`.
spring.mail.jndi-name= # Session JNDI name. When set, takes precedence over other Session settings.
spring.mail.password= # Login password of the SMTP server.
spring.mail.port= # SMTP server port.
spring.mail.properties.*= # Additional JavaMail Session properties.
spring.mail.protocol=smtp # Protocol used by the SMTP server.
spring.mail.test-connection=false # Whether to test that the mail server is available on startup.
spring.mail.username= # Login user of the SMTP server.
# APPLICATION SETTINGS (SpringApplication)
spring.main.allow-bean-definition-overriding=false # Whether bean definition overriding, by registering a definition with the
spring.main.banner-mode=console # Mode used to display the banner when the application runs.
spring.main.sources= # Sources (class names, package names, or XML resource locations) to include in the ApplicationContext.
spring.main.web-application-type= # Flag to explicitly request a specific type of web application. If not set, auto-detected b
# FILE ENCODING (FileEncodingApplicationListener)
spring.mandatory-file-encoding= # Expected character encoding the application must use.
# INTERNATIONALIZATION (MessageSourceProperties)
spring.messages.always-use-message-format=false # Whether to always apply the MessageFormat rules, parsing even messages witho
spring.messages.basename=messages # Comma-separated list of basenames (essentially a fully-qualified classpath location), each
spring.messages.cache-duration= # Loaded resource bundle files cache duration. When not set, bundles are cached forever. If a
spring.messages.encoding=UTF-8 # Message bundles encoding.

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spring.messages.fallback-to-system-locale=true # Whether to fall back to the system Locale if no files for a specific Locale h
spring.messages.use-code-as-default-message=false # Whether to use the message code as the default message instead of throwing
# OUTPUT
spring.output.ansi.enabled=detect # Configures the ANSI output.
# PID FILE (ApplicationPidFileWriter)
spring.pid.fail-on-write-error= # Fails if ApplicationPidFileWriter is used but it cannot write the PID file.
spring.pid.file= # Location of the PID file to write (if ApplicationPidFileWriter is used).
# PROFILES
spring.profiles.active= # Comma-separated list of active profiles. Can be overridden by a command line switch.
spring.profiles.include= # Unconditionally activate the specified comma-separated list of profiles (or list of profiles if usi
# QUARTZ SCHEDULER (QuartzProperties)
spring.quartz.auto-startup=true # Whether to automatically start the scheduler after initialization.
spring.quartz.jdbc.comment-prefix=-- # Prefix for single-line comments in SQL initialization scripts.
spring.quartz.jdbc.initialize-schema=embedded # Database schema initialization mode.
spring.quartz.jdbc.schema=classpath:org/quartz/impl/jdbcjobstore/tables_@@platform@@.sql # Path to the SQL file to use to init
spring.quartz.job-store-type=memory # Quartz job store type.
spring.quartz.overwrite-existing-jobs=false # Whether configured jobs should overwrite existing job definitions.
spring.quartz.properties.*= # Additional Quartz Scheduler properties.
spring.quartz.scheduler-name=quartzScheduler # Name of the scheduler.
spring.quartz.startup-delay=0s # Delay after which the scheduler is started once initialization completes.
spring.quartz.wait-for-jobs-to-complete-on-shutdown=false # Whether to wait for running jobs to complete on shutdown.
# REACTOR (ReactorCoreProperties)
spring.reactor.stacktrace-mode.enabled=false # Whether Reactor should collect stacktrace information at runtime.
# SENDGRID (SendGridAutoConfiguration)
spring.sendgrid.api-key= # SendGrid API key.
spring.sendgrid.proxy.host= # SendGrid proxy host.
spring.sendgrid.proxy.port= # SendGrid proxy port.
# TASK EXECUTION (TaskExecutionProperties)
spring.task.execution.pool.allow-core-thread-timeout=true # Whether core threads are allowed to time out. This enables dynamic
spring.task.execution.pool.core-size=8 # Core number of threads.
spring.task.execution.pool.keep-alive=60s # Time limit for which threads may remain idle before being terminated.
spring.task.execution.pool.max-size= # Maximum allowed number of threads. If tasks are filling up the queue, the pool can expa
spring.task.execution.pool.queue-capacity= # Queue capacity. An unbounded capacity does not increase the pool and therefore ig
spring.task.execution.thread-name-prefix=task- # Prefix to use for the names of newly created threads.
# TASK SCHEDULING (TaskSchedulingProperties)
spring.task.scheduling.pool.size=1 # Maximum allowed number of threads.
spring.task.scheduling.thread-name-prefix=scheduling- # Prefix to use for the names of newly created threads.
# ---------------------------------------# WEB PROPERTIES
# ---------------------------------------# EMBEDDED SERVER CONFIGURATION (ServerProperties)
server.address= # Network address to which the server should bind.
server.compression.enabled=false # Whether response compression is enabled.
server.compression.excluded-user-agents= # Comma-separated list of user agents for which responses should not be compressed.
server.compression.mime-types=text/html,text/xml,text/plain,text/css,text/javascript,application/javascript,application/json,a
server.compression.min-response-size=2KB # Minimum "Content-Length" value that is required for compression to be performed.
server.connection-timeout= # Time that connectors wait for another HTTP request before closing the connection. When not set, t
server.error.include-exception=false # Include the "exception" attribute.
server.error.include-stacktrace=never # When to include a "stacktrace" attribute.
server.error.path=/error # Path of the error controller.
server.error.whitelabel.enabled=true # Whether to enable the default error page displayed in browsers in case of a server erro
server.http2.enabled=false # Whether to enable HTTP/2 support, if the current environment supports it.
server.jetty.acceptors=-1 # Number of acceptor threads to use. When the value is -1, the default, the number of acceptors is d
server.jetty.accesslog.append=false # Append to log.
server.jetty.accesslog.date-format=dd/MMM/yyyy:HH:mm:ss Z # Timestamp format of the request log.
server.jetty.accesslog.enabled=false # Enable access log.
server.jetty.accesslog.extended-format=false # Enable extended NCSA format.
server.jetty.accesslog.file-date-format= # Date format to place in log file name.
server.jetty.accesslog.filename= # Log filename. If not specified, logs redirect to "System.err".
server.jetty.accesslog.locale= # Locale of the request log.

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server.jetty.accesslog.log-cookies=false # Enable logging of the request cookies.
server.jetty.accesslog.log-latency=false # Enable logging of request processing time.
server.jetty.accesslog.log-server=false # Enable logging of the request hostname.
server.jetty.accesslog.retention-period=31 # Number of days before rotated log files are deleted.
server.jetty.accesslog.time-zone=GMT # Timezone of the request log.
server.jetty.max-http-post-size=200000B # Maximum size of the HTTP post or put content.
server.jetty.selectors=-1 # Number of selector threads to use. When the value is -1, the default, the number of selectors is d
server.max-http-header-size=8KB # Maximum size of the HTTP message header.
server.port=8080 # Server HTTP port.
server.server-header= # Value to use for the Server response header (if empty, no header is sent).
server.use-forward-headers= # Whether X-Forwarded-* headers should be applied to the HttpRequest.
server.servlet.context-parameters.*= # Servlet context init parameters.
server.servlet.context-path= # Context path of the application.
server.servlet.application-display-name=application # Display name of the application.
server.servlet.jsp.class-name=org.apache.jasper.servlet.JspServlet # Class name of the servlet to use for JSPs.
server.servlet.jsp.init-parameters.*= # Init parameters used to configure the JSP servlet.
server.servlet.jsp.registered=true # Whether the JSP servlet is registered.
server.servlet.session.cookie.comment= # Comment for the session cookie.
server.servlet.session.cookie.domain= # Domain for the session cookie.
server.servlet.session.cookie.http-only= # Whether to use "HttpOnly" cookies for session cookies.
server.servlet.session.cookie.max-age= # Maximum age of the session cookie. If a duration suffix is not specified, seconds wil
server.servlet.session.cookie.name= # Session cookie name.
server.servlet.session.cookie.path= # Path of the session cookie.
server.servlet.session.cookie.secure= # Whether to always mark the session cookie as secure.
server.servlet.session.persistent=false # Whether to persist session data between restarts.
server.servlet.session.store-dir= # Directory used to store session data.
server.servlet.session.timeout=30m # Session timeout. If a duration suffix is not specified, seconds will be used.
server.servlet.session.tracking-modes= # Session tracking modes.
server.ssl.ciphers= # Supported SSL ciphers.
server.ssl.client-auth= # Client authentication mode.
server.ssl.enabled=true # Whether to enable SSL support.
server.ssl.enabled-protocols= # Enabled SSL protocols.
server.ssl.key-alias= # Alias that identifies the key in the key store.
server.ssl.key-password= # Password used to access the key in the key store.
server.ssl.key-store= # Path to the key store that holds the SSL certificate (typically a jks file).
server.ssl.key-store-password= # Password used to access the key store.
server.ssl.key-store-provider= # Provider for the key store.
server.ssl.key-store-type= # Type of the key store.
server.ssl.protocol=TLS # SSL protocol to use.
server.ssl.trust-store= # Trust store that holds SSL certificates.
server.ssl.trust-store-password= # Password used to access the trust store.
server.ssl.trust-store-provider= # Provider for the trust store.
server.ssl.trust-store-type= # Type of the trust store.
server.tomcat.accept-count=100 # Maximum queue length for incoming connection requests when all possible request processing th
server.tomcat.accesslog.buffered=true # Whether to buffer output such that it is flushed only periodically.
server.tomcat.accesslog.directory=logs # Directory in which log files are created. Can be absolute or relative to the Tomcat b
server.tomcat.accesslog.enabled=false # Enable access log.
server.tomcat.accesslog.file-date-format=.yyyy-MM-dd # Date format to place in the log file name.
server.tomcat.accesslog.pattern=common # Format pattern for access logs.
server.tomcat.accesslog.prefix=access_log # Log file name prefix.
server.tomcat.accesslog.rename-on-rotate=false # Whether to defer inclusion of the date stamp in the file name until rotate ti
server.tomcat.accesslog.request-attributes-enabled=false # Set request attributes for the IP address, Hostname, protocol, and
server.tomcat.accesslog.rotate=true # Whether to enable access log rotation.
server.tomcat.accesslog.suffix=.log # Log file name suffix.
server.tomcat.additional-tld-skip-patterns= # Comma-separated list of additional patterns that match jars to ignore for TLD sc
server.tomcat.background-processor-delay=10s # Delay between the invocation of backgroundProcess methods. If a duration suffix
server.tomcat.basedir= # Tomcat base directory. If not specified, a temporary directory is used.
server.tomcat.internal-proxies=10\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}|\\
192\\.168\\.\\d{1,3}\\.\\d{1,3}|\\
169\\.254\\.\\d{1,3}\\.\\d{1,3}|\\
127\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}|\\
172\\.1[6-9]{1}\\.\\d{1,3}\\.\\d{1,3}|\\
172\\.2[0-9]{1}\\.\\d{1,3}\\.\\d{1,3}|\\
172\\.3[0-1]{1}\\.\\d{1,3}\\.\\d{1,3}\\
0:0:0:0:0:0:0:1\\
::1 # Regular expression that matches proxies that are to be trusted.
server.tomcat.max-connections=10000 # Maximum number of connections that the server accepts and processes at any given time.
server.tomcat.max-http-post-size=2MB # Maximum size of the HTTP post content.
server.tomcat.max-swallow-size=2MB # Maximum amount of request body to swallow.
server.tomcat.max-threads=200 # Maximum amount of worker threads.

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server.tomcat.min-spare-threads=10 # Minimum amount of worker threads.
server.tomcat.port-header=X-Forwarded-Port # Name of the HTTP header used to override the original port value.
server.tomcat.protocol-header= # Header that holds the incoming protocol, usually named "X-Forwarded-Proto".
server.tomcat.protocol-header-https-value=https # Value of the protocol header indicating whether the incoming request uses SS
server.tomcat.redirect-context-root=true # Whether requests to the context root should be redirected by appending a / to the p
server.tomcat.remote-ip-header= # Name of the HTTP header from which the remote IP is extracted. For instance, `X-FORWARDED-FO
server.tomcat.resource.allow-caching=true # Whether static resource caching is permitted for this web application.
server.tomcat.resource.cache-ttl= # Time-to-live of the static resource cache.
server.tomcat.uri-encoding=UTF-8 # Character encoding to use to decode the URI.
server.tomcat.use-relative-redirects= # Whether HTTP 1.1 and later location headers generated by a call to sendRedirect will u
server.undertow.accesslog.dir= # Undertow access log directory.
server.undertow.accesslog.enabled=false # Whether to enable the access log.
server.undertow.accesslog.pattern=common # Format pattern for access logs.
server.undertow.accesslog.prefix=access_log. # Log file name prefix.
server.undertow.accesslog.rotate=true # Whether to enable access log rotation.
server.undertow.accesslog.suffix=log # Log file name suffix.
server.undertow.buffer-size= # Size of each buffer.
server.undertow.direct-buffers= # Whether to allocate buffers outside the Java heap. The default is derived from the maximum a
server.undertow.eager-filter-init=true # Whether servlet filters should be initialized on startup.
server.undertow.io-threads= # Number of I/O threads to create for the worker. The default is derived from the number of availa
server.undertow.max-http-post-size=-1B # Maximum size of the HTTP post content. When the value is -1, the default, the size is
server.undertow.worker-threads= # Number of worker threads. The default is 8 times the number of I/O threads.
# FREEMARKER (FreeMarkerProperties)
spring.freemarker.allow-request-override=false # Whether HttpServletRequest attributes are allowed to override (hide) controll
spring.freemarker.allow-session-override=false # Whether HttpSession attributes are allowed to override (hide) controller gene
spring.freemarker.cache=false # Whether to enable template caching.
spring.freemarker.charset=UTF-8 # Template encoding.
spring.freemarker.check-template-location=true # Whether to check that the templates location exists.
spring.freemarker.content-type=text/html # Content-Type value.
spring.freemarker.enabled=true # Whether to enable MVC view resolution for this technology.
spring.freemarker.expose-request-attributes=false # Whether all request attributes should be added to the model prior to mergi
spring.freemarker.expose-session-attributes=false # Whether all HttpSession attributes should be added to the model prior to m
spring.freemarker.expose-spring-macro-helpers=true # Whether to expose a RequestContext for use by Spring's macro library, und
spring.freemarker.prefer-file-system-access=true # Whether to prefer file system access for template loading. File system acce
spring.freemarker.prefix= # Prefix that gets prepended to view names when building a URL.
spring.freemarker.request-context-attribute= # Name of the RequestContext attribute for all views.
spring.freemarker.settings.*= # Well-known FreeMarker keys which are passed to FreeMarker's Configuration.
spring.freemarker.suffix=.ftl # Suffix that gets appended to view names when building a URL.
spring.freemarker.template-loader-path=classpath:/templates/ # Comma-separated list of template paths.
spring.freemarker.view-names= # White list of view names that can be resolved.
# GROOVY TEMPLATES (GroovyTemplateProperties)
spring.groovy.template.allow-request-override=false # Whether HttpServletRequest attributes are allowed to override (hide) con
spring.groovy.template.allow-session-override=false # Whether HttpSession attributes are allowed to override (hide) controller
spring.groovy.template.cache=false # Whether to enable template caching.
spring.groovy.template.charset=UTF-8 # Template encoding.
spring.groovy.template.check-template-location=true # Whether to check that the templates location exists.
spring.groovy.template.configuration.*= # See GroovyMarkupConfigurer
spring.groovy.template.content-type=text/html # Content-Type value.
spring.groovy.template.enabled=true # Whether to enable MVC view resolution for this technology.
spring.groovy.template.expose-request-attributes=false # Whether all request attributes should be added to the model prior to
spring.groovy.template.expose-session-attributes=false # Whether all HttpSession attributes should be added to the model prior
spring.groovy.template.expose-spring-macro-helpers=true # Whether to expose a RequestContext for use by Spring's macro library
spring.groovy.template.prefix= # Prefix that gets prepended to view names when building a URL.
spring.groovy.template.request-context-attribute= # Name of the RequestContext attribute for all views.
spring.groovy.template.resource-loader-path=classpath:/templates/ # Template path.
spring.groovy.template.suffix=.tpl # Suffix that gets appended to view names when building a URL.
spring.groovy.template.view-names= # White list of view names that can be resolved.
# SPRING HATEOAS (HateoasProperties)
spring.hateoas.use-hal-as-default-json-media-type=true # Whether application/hal+json responses should be sent to requests tha
# HTTP (HttpProperties)
spring.http.converters.preferred-json-mapper= # Preferred JSON mapper to use for HTTP message conversion. By default, auto-det
spring.http.encoding.charset=UTF-8 # Charset of HTTP requests and responses. Added to the "Content-Type" header if not set exp
spring.http.encoding.enabled=true # Whether to enable http encoding support.
spring.http.encoding.force= # Whether to force the encoding to the configured charset on HTTP requests and responses.
spring.http.encoding.force-request= # Whether to force the encoding to the configured charset on HTTP requests. Defaults to tr
spring.http.encoding.force-response= # Whether to force the encoding to the configured charset on HTTP responses.

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spring.http.encoding.mapping= # Locale in which to encode mapping.
spring.http.log-request-details=false # Whether logging of (potentially sensitive) request details at DEBUG and TRACE level is
# MULTIPART (MultipartProperties)
spring.servlet.multipart.enabled=true # Whether to enable support of multipart uploads.
spring.servlet.multipart.file-size-threshold=0B # Threshold after which files are written to disk.
spring.servlet.multipart.location= # Intermediate location of uploaded files.
spring.servlet.multipart.max-file-size=1MB # Max file size.
spring.servlet.multipart.max-request-size=10MB # Max request size.
spring.servlet.multipart.resolve-lazily=false # Whether to resolve the multipart request lazily at the time of file or paramet
# JACKSON (JacksonProperties)
spring.jackson.date-format= # Date format string or a fully-qualified date format class name. For instance, `yyyy-MM-dd HH:mm:
spring.jackson.default-property-inclusion= # Controls the inclusion of properties during serialization. Configured with one of
spring.jackson.deserialization.*= # Jackson on/off features that affect the way Java objects are deserialized.
spring.jackson.generator.*= # Jackson on/off features for generators.
spring.jackson.joda-date-time-format= # Joda date time format string. If not configured, "date-format" is used as a fallback i
spring.jackson.locale= # Locale used for formatting.
spring.jackson.mapper.*= # Jackson general purpose on/off features.
spring.jackson.parser.*= # Jackson on/off features for parsers.
spring.jackson.property-naming-strategy= # One of the constants on Jackson's PropertyNamingStrategy. Can also be a fully-quali
spring.jackson.serialization.*= # Jackson on/off features that affect the way Java objects are serialized.
spring.jackson.time-zone= # Time zone used when formatting dates. For instance, "America/Los_Angeles" or "GMT+10".
spring.jackson.visibility.*= # Jackson visibility thresholds that can be used to limit which methods (and fields) are auto-det
# GSON (GsonProperties)
spring.gson.date-format= # Format to use when serializing Date objects.
spring.gson.disable-html-escaping= # Whether to disable the escaping of HTML characters such as '<', '>', etc.
spring.gson.disable-inner-class-serialization= # Whether to exclude inner classes during serialization.
spring.gson.enable-complex-map-key-serialization= # Whether to enable serialization of complex map keys (i.e. non-primitives).
spring.gson.exclude-fields-without-expose-annotation= # Whether to exclude all fields from consideration for serialization or
spring.gson.field-naming-policy= # Naming policy that should be applied to an object's field during serialization and deserial
spring.gson.generate-non-executable-json= # Whether to generate non executable JSON by prefixing the output with some special
spring.gson.lenient= # Whether to be lenient about parsing JSON that doesn't conform to RFC 4627.
spring.gson.long-serialization-policy= # Serialization policy for Long and long types.
spring.gson.pretty-printing= # Whether to output serialized JSON that fits in a page for pretty printing.
spring.gson.serialize-nulls= # Whether to serialize null fields.
# JERSEY (JerseyProperties)
spring.jersey.application-path= # Path that serves as the base URI for the application. If specified, overrides the value of "
spring.jersey.filter.order=0 # Jersey filter chain order.
spring.jersey.init.*= # Init parameters to pass to Jersey through the servlet or filter.
spring.jersey.servlet.load-on-startup=-1 # Load on startup priority of the Jersey servlet.
spring.jersey.type=servlet # Jersey integration type.
# SPRING LDAP (LdapProperties)
spring.ldap.anonymous-read-only=false # Whether read-only operations should use an anonymous environment.
spring.ldap.base= # Base suffix from which all operations should originate.
spring.ldap.base-environment.*= # LDAP specification settings.
spring.ldap.password= # Login password of the server.
spring.ldap.urls= # LDAP URLs of the server.
spring.ldap.username= # Login username of the server.
# EMBEDDED LDAP (EmbeddedLdapProperties)
spring.ldap.embedded.base-dn= # List of base DNs.
spring.ldap.embedded.credential.username= # Embedded LDAP username.
spring.ldap.embedded.credential.password= # Embedded LDAP password.
spring.ldap.embedded.ldif=classpath:schema.ldif # Schema (LDIF) script resource reference.
spring.ldap.embedded.port=0 # Embedded LDAP port.
spring.ldap.embedded.validation.enabled=true # Whether to enable LDAP schema validation.
spring.ldap.embedded.validation.schema= # Path to the custom schema.
# MUSTACHE TEMPLATES (MustacheAutoConfiguration)
spring.mustache.allow-request-override=false # Whether HttpServletRequest attributes are allowed to override (hide) controller
spring.mustache.allow-session-override=false # Whether HttpSession attributes are allowed to override (hide) controller genera
spring.mustache.cache=false # Whether to enable template caching.
spring.mustache.charset=UTF-8 # Template encoding.
spring.mustache.check-template-location=true # Whether to check that the templates location exists.
spring.mustache.content-type=text/html # Content-Type value.
spring.mustache.enabled=true # Whether to enable MVC view resolution for this technology.

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spring.mustache.expose-request-attributes=false # Whether all request attributes should be added to the model prior to merging
spring.mustache.expose-session-attributes=false # Whether all HttpSession attributes should be added to the model prior to mer
spring.mustache.expose-spring-macro-helpers=true # Whether to expose a RequestContext for use by Spring's macro library, under
spring.mustache.prefix=classpath:/templates/ # Prefix to apply to template names.
spring.mustache.request-context-attribute= # Name of the RequestContext attribute for all views.
spring.mustache.suffix=.mustache # Suffix to apply to template names.
spring.mustache.view-names= # White list of view names that can be resolved.
# SPRING MVC (WebMvcProperties)
spring.mvc.async.request-timeout= # Amount of time before asynchronous request handling times out.
spring.mvc.contentnegotiation.favor-parameter=false # Whether a request parameter ("format" by default) should be used to dete
spring.mvc.contentnegotiation.favor-path-extension=false # Whether the path extension in the URL path should be used to determ
spring.mvc.contentnegotiation.media-types.*= # Map file extensions to media types for content negotiation. For instance, yml t
spring.mvc.contentnegotiation.parameter-name= # Query parameter name to use when "favor-parameter" is enabled.
spring.mvc.date-format= # Date format to use. For instance, `dd/MM/yyyy`.
spring.mvc.dispatch-trace-request=false # Whether to dispatch TRACE requests to the FrameworkServlet doService method.
spring.mvc.dispatch-options-request=true # Whether to dispatch OPTIONS requests to the FrameworkServlet doService method.
spring.mvc.favicon.enabled=true # Whether to enable resolution of favicon.ico.
spring.mvc.formcontent.filter.enabled=true # Whether to enable Spring's FormContentFilter.
spring.mvc.hiddenmethod.filter.enabled=true # Whether to enable Spring's HiddenHttpMethodFilter.
spring.mvc.ignore-default-model-on-redirect=true # Whether the content of the "default" model should be ignored during redirec
spring.mvc.locale= # Locale to use. By default, this locale is overridden by the "Accept-Language" header.
spring.mvc.locale-resolver=accept-header # Define how the locale should be resolved.
spring.mvc.log-resolved-exception=false # Whether to enable warn logging of exceptions resolved by a "HandlerExceptionResolver
spring.mvc.message-codes-resolver-format= # Formatting strategy for message codes. For instance, `PREFIX_ERROR_CODE`.
spring.mvc.pathmatch.use-registered-suffix-pattern=false # Whether suffix pattern matching should work only against extensions
spring.mvc.pathmatch.use-suffix-pattern=false # Whether to use suffix pattern match (".*") when matching patterns to requests.
spring.mvc.servlet.load-on-startup=-1 # Load on startup priority of the dispatcher servlet.
spring.mvc.servlet.path=/ # Path of the dispatcher servlet.
spring.mvc.static-path-pattern=/** # Path pattern used for static resources.
spring.mvc.throw-exception-if-no-handler-found=false # Whether a "NoHandlerFoundException" should be thrown if no Handler was
spring.mvc.view.prefix= # Spring MVC view prefix.
spring.mvc.view.suffix= # Spring MVC view suffix.
# SPRING RESOURCES HANDLING (ResourceProperties)
spring.resources.add-mappings=true # Whether to enable default resource handling.
spring.resources.cache.cachecontrol.cache-private= # Indicate that the response message is intended for a single user and must
spring.resources.cache.cachecontrol.cache-public= # Indicate that any cache may store the response.
spring.resources.cache.cachecontrol.max-age= # Maximum time the response should be cached, in seconds if no duration suffix is
spring.resources.cache.cachecontrol.must-revalidate= # Indicate that once it has become stale, a cache must not use the respon
spring.resources.cache.cachecontrol.no-cache= # Indicate that the cached response can be reused only if re-validated with the
spring.resources.cache.cachecontrol.no-store= # Indicate to not cache the response in any case.
spring.resources.cache.cachecontrol.no-transform= # Indicate intermediaries (caches and others) that they should not transform
spring.resources.cache.cachecontrol.proxy-revalidate= # Same meaning as the "must-revalidate" directive, except that it does n
spring.resources.cache.cachecontrol.s-max-age= # Maximum time the response should be cached by shared caches, in seconds if no
spring.resources.cache.cachecontrol.stale-if-error= # Maximum time the response may be used when errors are encountered, in se
spring.resources.cache.cachecontrol.stale-while-revalidate= # Maximum time the response can be served after it becomes stale,
spring.resources.cache.period= # Cache period for the resources served by the resource handler. If a duration suffix is not sp
spring.resources.chain.cache=true # Whether to enable caching in the Resource chain.
spring.resources.chain.compressed=false # Whether to enable resolution of already compressed resources (gzip, brotli).
spring.resources.chain.enabled= # Whether to enable the Spring Resource Handling chain. By default, disabled unless at least o
spring.resources.chain.html-application-cache=false # Whether to enable HTML5 application cache manifest rewriting.
spring.resources.chain.strategy.content.enabled=false # Whether to enable the content Version Strategy.
spring.resources.chain.strategy.content.paths=/** # Comma-separated list of patterns to apply to the content Version Strategy.
spring.resources.chain.strategy.fixed.enabled=false # Whether to enable the fixed Version Strategy.
spring.resources.chain.strategy.fixed.paths=/** # Comma-separated list of patterns to apply to the fixed Version Strategy.
spring.resources.chain.strategy.fixed.version= # Version string to use for the fixed Version Strategy.
spring.resources.static-locations=classpath:/META-INF/resources/,classpath:/resources/,classpath:/static/,classpath:/public/ #
# SPRING SESSION (SessionProperties)
spring.session.store-type= # Session store type.
spring.session.timeout= # Session timeout. If a duration suffix is not specified, seconds will be used.
spring.session.servlet.filter-order=-2147483598 # Session repository filter order.
spring.session.servlet.filter-dispatcher-types=async,error,request # Session repository filter dispatcher types.
# SPRING SESSION HAZELCAST (HazelcastSessionProperties)
spring.session.hazelcast.flush-mode=on-save # Sessions flush mode.
spring.session.hazelcast.map-name=spring:session:sessions # Name of the map used to store sessions.
# SPRING SESSION JDBC (JdbcSessionProperties)

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spring.session.jdbc.cleanup-cron=0 * * * * * # Cron expression for expired session cleanup job.
spring.session.jdbc.initialize-schema=embedded # Database schema initialization mode.
spring.session.jdbc.schema=classpath:org/springframework/session/jdbc/schema-@@platform@@.sql # Path to the SQL file to use to
spring.session.jdbc.table-name=SPRING_SESSION # Name of the database table used to store sessions.
# SPRING SESSION MONGODB (MongoSessionProperties)
spring.session.mongodb.collection-name=sessions # Collection name used to store sessions.
# SPRING SESSION REDIS (RedisSessionProperties)
spring.session.redis.cleanup-cron=0 * * * * * # Cron expression for expired session cleanup job.
spring.session.redis.flush-mode=on-save # Sessions flush mode.
spring.session.redis.namespace=spring:session # Namespace for keys used to store sessions.
# THYMELEAF (ThymeleafAutoConfiguration)
spring.thymeleaf.cache=true # Whether to enable template caching.
spring.thymeleaf.check-template=true # Whether to check that the template exists before rendering it.
spring.thymeleaf.check-template-location=true # Whether to check that the templates location exists.
spring.thymeleaf.enabled=true # Whether to enable Thymeleaf view resolution for Web frameworks.
spring.thymeleaf.enable-spring-el-compiler=false # Enable the SpringEL compiler in SpringEL expressions.
spring.thymeleaf.encoding=UTF-8 # Template files encoding.
spring.thymeleaf.excluded-view-names= # Comma-separated list of view names (patterns allowed) that should be excluded from res
spring.thymeleaf.mode=HTML # Template mode to be applied to templates. See also Thymeleaf's TemplateMode enum.
spring.thymeleaf.prefix=classpath:/templates/ # Prefix that gets prepended to view names when building a URL.
spring.thymeleaf.reactive.chunked-mode-view-names= # Comma-separated list of view names (patterns allowed) that should be the
spring.thymeleaf.reactive.full-mode-view-names= # Comma-separated list of view names (patterns allowed) that should be execute
spring.thymeleaf.reactive.max-chunk-size=0B # Maximum size of data buffers used for writing to the response.
spring.thymeleaf.reactive.media-types= # Media types supported by the view technology.
spring.thymeleaf.render-hidden-markers-before-checkboxes=false # Whether hidden form inputs acting as markers for checkboxes s
spring.thymeleaf.servlet.content-type=text/html # Content-Type value written to HTTP responses.
spring.thymeleaf.servlet.produce-partial-output-while-processing=true # Whether Thymeleaf should start writing partial output
spring.thymeleaf.suffix=.html # Suffix that gets appended to view names when building a URL.
spring.thymeleaf.template-resolver-order= # Order of the template resolver in the chain.
spring.thymeleaf.view-names= # Comma-separated list of view names (patterns allowed) that can be resolved.
# SPRING WEBFLUX (WebFluxProperties)
spring.webflux.date-format= # Date format to use. For instance, `dd/MM/yyyy`.
spring.webflux.hiddenmethod.filter.enabled=true # Whether to enable Spring's HiddenHttpMethodFilter.
spring.webflux.static-path-pattern=/** # Path pattern used for static resources.
# SPRING WEB SERVICES (WebServicesProperties)
spring.webservices.path=/services # Path that serves as the base URI for the services.
spring.webservices.servlet.init= # Servlet init parameters to pass to Spring Web Services.
spring.webservices.servlet.load-on-startup=-1 # Load on startup priority of the Spring Web Services servlet.
spring.webservices.wsdl-locations= # Comma-separated list of locations of WSDLs and accompanying XSDs to be exposed as beans.

# ---------------------------------------# SECURITY PROPERTIES
# ---------------------------------------# SECURITY (SecurityProperties)
spring.security.filter.order=-100 # Security filter chain order.
spring.security.filter.dispatcher-types=async,error,request # Security filter chain dispatcher types.
spring.security.user.name=user # Default user name.
spring.security.user.password= # Password for the default user name.
spring.security.user.roles= # Granted roles for the default user name.
# SECURITY OAUTH2 CLIENT (OAuth2ClientProperties)
spring.security.oauth2.client.provider.*= # OAuth provider details.
spring.security.oauth2.client.registration.*= # OAuth client registrations.
# SECURITY OAUTH2 RESOURCE SERVER (OAuth2ResourceServerProperties)
spring.security.oauth2.resourceserver.jwt.jwk-set-uri= # JSON Web Key URI to use to verify the JWT token.
spring.security.oauth2.resourceserver.jwt.issuer-uri= # URI that an OpenID Connect Provider asserts as its Issuer Identifie
# ---------------------------------------# DATA PROPERTIES
# ---------------------------------------# FLYWAY (FlywayProperties)
spring.flyway.baseline-description=<< Flyway Baseline >> # Description to tag an existing schema with when applying a baseline

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spring.flyway.baseline-on-migrate=false # Whether to automatically call baseline when migrating a non-empty schema.
spring.flyway.baseline-version=1 # Version to tag an existing schema with when executing baseline.
spring.flyway.check-location=true # Whether to check that migration scripts location exists.
spring.flyway.clean-disabled=false # Whether to disable cleaning of the database.
spring.flyway.clean-on-validation-error=false # Whether to automatically call clean when a validation error occurs.
spring.flyway.connect-retries=0 # Maximum number of retries when attempting to connect to the database.
spring.flyway.enabled=true # Whether to enable flyway.
spring.flyway.encoding=UTF-8 # Encoding of SQL migrations.
spring.flyway.group=false # Whether to group all pending migrations together in the same transaction when applying them.
spring.flyway.ignore-future-migrations=true # Whether to ignore future migrations when reading the schema history table.
spring.flyway.ignore-ignored-migrations=false # Whether to ignore ignored migrations when reading the schema history table.
spring.flyway.ignore-missing-migrations=false # Whether to ignore missing migrations when reading the schema history table.
spring.flyway.ignore-pending-migrations=false # Whether to ignore pending migrations when reading the schema history table.
spring.flyway.init-sqls= # SQL statements to execute to initialize a connection immediately after obtaining it.
spring.flyway.installed-by= # Username recorded in the schema history table as having applied the migration.
spring.flyway.locations=classpath:db/migration # Locations of migrations scripts. Can contain the special "{vendor}" placehold
spring.flyway.mixed=false # Whether to allow mixing transactional and non-transactional statements within the same migration.
spring.flyway.out-of-order=false # Whether to allow migrations to be run out of order.
spring.flyway.password= # Login password of the database to migrate.
spring.flyway.placeholder-prefix=${ # Prefix of placeholders in migration scripts.
spring.flyway.placeholder-replacement=true # Perform placeholder replacement in migration scripts.
spring.flyway.placeholder-suffix=} # Suffix of placeholders in migration scripts.
spring.flyway.placeholders= # Placeholders and their replacements to apply to sql migration scripts.
spring.flyway.repeatable-sql-migration-prefix=R # File name prefix for repeatable SQL migrations.
spring.flyway.schemas= # Scheme names managed by Flyway (case-sensitive).
spring.flyway.skip-default-callbacks=false # Whether to skip default callbacks. If true, only custom callbacks are used.
spring.flyway.skip-default-resolvers=false # Whether to skip default resolvers. If true, only custom resolvers are used.
spring.flyway.sql-migration-prefix=V # File name prefix for SQL migrations.
spring.flyway.sql-migration-separator=__ # File name separator for SQL migrations.
spring.flyway.sql-migration-suffixes=.sql # File name suffix for SQL migrations.
spring.flyway.table=flyway_schema_history # Name of the schema schema history table that will be used by Flyway.
spring.flyway.target= # Target version up to which migrations should be considered.
spring.flyway.url= # JDBC url of the database to migrate. If not set, the primary configured data source is used.
spring.flyway.user= # Login user of the database to migrate.
spring.flyway.validate-on-migrate=true # Whether to automatically call validate when performing a migration.
# LIQUIBASE (LiquibaseProperties)
spring.liquibase.change-log=classpath:/db/changelog/db.changelog-master.yaml # Change log configuration path.
spring.liquibase.check-change-log-location=true # Whether to check that the change log location exists.
spring.liquibase.contexts= # Comma-separated list of runtime contexts to use.
spring.liquibase.database-change-log-lock-table=DATABASECHANGELOGLOCK # Name of table to use for tracking concurrent Liquibase
spring.liquibase.database-change-log-table=DATABASECHANGELOG # Name of table to use for tracking change history.
spring.liquibase.default-schema= # Default database schema.
spring.liquibase.drop-first=false # Whether to first drop the database schema.
spring.liquibase.enabled=true # Whether to enable Liquibase support.
spring.liquibase.labels= # Comma-separated list of runtime labels to use.
spring.liquibase.liquibase-schema= # Schema to use for Liquibase objects.
spring.liquibase.liquibase-tablespace= # Tablespace to use for Liquibase objects.
spring.liquibase.parameters.*= # Change log parameters.
spring.liquibase.password= # Login password of the database to migrate.
spring.liquibase.rollback-file= # File to which rollback SQL is written when an update is performed.
spring.liquibase.test-rollback-on-update=false # Whether rollback should be tested before update is performed.
spring.liquibase.url= # JDBC URL of the database to migrate. If not set, the primary configured data source is used.
spring.liquibase.user= # Login user of the database to migrate.
# COUCHBASE (CouchbaseProperties)
spring.couchbase.bootstrap-hosts= # Couchbase nodes (host or IP address) to bootstrap from.
spring.couchbase.bucket.name=default # Name of the bucket to connect to.
spring.couchbase.bucket.password= # Password of the bucket.
spring.couchbase.env.endpoints.key-value=1 # Number of sockets per node against the key/value service.
spring.couchbase.env.endpoints.queryservice.min-endpoints=1 # Minimum number of sockets per node.
spring.couchbase.env.endpoints.queryservice.max-endpoints=1 # Maximum number of sockets per node.
spring.couchbase.env.endpoints.viewservice.min-endpoints=1 # Minimum number of sockets per node.
spring.couchbase.env.endpoints.viewservice.max-endpoints=1 # Maximum number of sockets per node.
spring.couchbase.env.ssl.enabled= # Whether to enable SSL support. Enabled automatically if a "keyStore" is provided unless sp
spring.couchbase.env.ssl.key-store= # Path to the JVM key store that holds the certificates.
spring.couchbase.env.ssl.key-store-password= # Password used to access the key store.
spring.couchbase.env.timeouts.connect=5000ms # Bucket connections timeouts.
spring.couchbase.env.timeouts.key-value=2500ms # Blocking operations performed on a specific key timeout.
spring.couchbase.env.timeouts.query=7500ms # N1QL query operations timeout.

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spring.couchbase.env.timeouts.socket-connect=1000ms # Socket connect connections timeout.
spring.couchbase.env.timeouts.view=7500ms # Regular and geospatial view operations timeout.
# DAO (PersistenceExceptionTranslationAutoConfiguration)
spring.dao.exceptiontranslation.enabled=true # Whether to enable the PersistenceExceptionTranslationPostProcessor.
# CASSANDRA (CassandraProperties)
spring.data.cassandra.cluster-name= # Name of the Cassandra cluster.
spring.data.cassandra.compression=none # Compression supported by the Cassandra binary protocol.
spring.data.cassandra.connect-timeout= # Socket option: connection time out.
spring.data.cassandra.consistency-level= # Queries consistency level.
spring.data.cassandra.contact-points=localhost # Cluster node addresses.
spring.data.cassandra.fetch-size= # Queries default fetch size.
spring.data.cassandra.jmx-enabled=false # Whether to enable JMX reporting.
spring.data.cassandra.keyspace-name= # Keyspace name to use.
spring.data.cassandra.port= # Port of the Cassandra server.
spring.data.cassandra.password= # Login password of the server.
spring.data.cassandra.pool.heartbeat-interval=30s # Heartbeat interval after which a message is sent on an idle connection to
spring.data.cassandra.pool.idle-timeout=120s # Idle timeout before an idle connection is removed. If a duration suffix is not
spring.data.cassandra.pool.max-queue-size=256 # Maximum number of requests that get queued if no connection is available.
spring.data.cassandra.pool.pool-timeout=5000ms # Pool timeout when trying to acquire a connection from a host's pool.
spring.data.cassandra.read-timeout= # Socket option: read time out.
spring.data.cassandra.repositories.type=auto # Type of Cassandra repositories to enable.
spring.data.cassandra.serial-consistency-level= # Queries serial consistency level.
spring.data.cassandra.schema-action=none # Schema action to take at startup.
spring.data.cassandra.ssl=false # Enable SSL support.
spring.data.cassandra.username= # Login user of the server.
# DATA COUCHBASE (CouchbaseDataProperties)
spring.data.couchbase.auto-index=false # Automatically create views and indexes.
spring.data.couchbase.consistency=read-your-own-writes # Consistency to apply by default on generated queries.
spring.data.couchbase.repositories.type=auto # Type of Couchbase repositories to enable.
# ELASTICSEARCH (ElasticsearchProperties)
spring.data.elasticsearch.cluster-name=elasticsearch # Elasticsearch cluster name.
spring.data.elasticsearch.cluster-nodes= # Comma-separated list of cluster node addresses.
spring.data.elasticsearch.properties.*= # Additional properties used to configure the client.
spring.data.elasticsearch.repositories.enabled=true # Whether to enable Elasticsearch repositories.
# DATA JDBC
spring.data.jdbc.repositories.enabled=true # Whether to enable JDBC repositories.
# DATA LDAP
spring.data.ldap.repositories.enabled=true # Whether to enable LDAP repositories.
# MONGODB (MongoProperties)
spring.data.mongodb.authentication-database= # Authentication database name.
spring.data.mongodb.database= # Database name.
spring.data.mongodb.field-naming-strategy= # Fully qualified name of the FieldNamingStrategy to use.
spring.data.mongodb.grid-fs-database= # GridFS database name.
spring.data.mongodb.host= # Mongo server host. Cannot be set with URI.
spring.data.mongodb.password= # Login password of the mongo server. Cannot be set with URI.
spring.data.mongodb.port= # Mongo server port. Cannot be set with URI.
spring.data.mongodb.repositories.type=auto # Type of Mongo repositories to enable.
spring.data.mongodb.uri=mongodb://localhost/test # Mongo database URI. Cannot be set with host, port and credentials.
spring.data.mongodb.username= # Login user of the mongo server. Cannot be set with URI.
# DATA REDIS
spring.data.redis.repositories.enabled=true # Whether to enable Redis repositories.
# NEO4J (Neo4jProperties)
spring.data.neo4j.auto-index=none # Auto index mode.
spring.data.neo4j.embedded.enabled=true # Whether to enable embedded mode if the embedded driver is available.
spring.data.neo4j.open-in-view=true # Register OpenSessionInViewInterceptor. Binds a Neo4j Session to the thread for the entir
spring.data.neo4j.password= # Login password of the server.
spring.data.neo4j.repositories.enabled=true # Whether to enable Neo4j repositories.
spring.data.neo4j.uri= # URI used by the driver. Auto-detected by default.
spring.data.neo4j.username= # Login user of the server.
# DATA REST (RepositoryRestProperties)

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spring.data.rest.base-path= # Base path to be used by Spring Data REST to expose repository resources.
spring.data.rest.default-media-type= # Content type to use as a default when none is specified.
spring.data.rest.default-page-size= # Default size of pages.
spring.data.rest.detection-strategy=default # Strategy to use to determine which repositories get exposed.
spring.data.rest.enable-enum-translation= # Whether to enable enum value translation through the Spring Data REST default reso
spring.data.rest.limit-param-name= # Name of the URL query string parameter that indicates how many results to return at once.
spring.data.rest.max-page-size= # Maximum size of pages.
spring.data.rest.page-param-name= # Name of the URL query string parameter that indicates what page to return.
spring.data.rest.return-body-on-create= # Whether to return a response body after creating an entity.
spring.data.rest.return-body-on-update= # Whether to return a response body after updating an entity.
spring.data.rest.sort-param-name= # Name of the URL query string parameter that indicates what direction to sort results.
# SOLR (SolrProperties)
spring.data.solr.host=http://127.0.0.1:8983/solr # Solr host. Ignored if "zk-host" is set.
spring.data.solr.repositories.enabled=true # Whether to enable Solr repositories.
spring.data.solr.zk-host= # ZooKeeper host address in the form HOST:PORT.
# DATA WEB (SpringDataWebProperties)
spring.data.web.pageable.default-page-size=20 # Default page size.
spring.data.web.pageable.max-page-size=2000 # Maximum page size to be accepted.
spring.data.web.pageable.one-indexed-parameters=false # Whether to expose and assume 1-based page number indexes.
spring.data.web.pageable.page-parameter=page # Page index parameter name.
spring.data.web.pageable.prefix= # General prefix to be prepended to the page number and page size parameters.
spring.data.web.pageable.qualifier-delimiter=_ # Delimiter to be used between the qualifier and the actual page number and siz
spring.data.web.pageable.size-parameter=size # Page size parameter name.
spring.data.web.sort.sort-parameter=sort # Sort parameter name.
# DATASOURCE (DataSourceAutoConfiguration & DataSourceProperties)
spring.datasource.continue-on-error=false # Whether to stop if an error occurs while initializing the database.
spring.datasource.data= # Data (DML) script resource references.
spring.datasource.data-username= # Username of the database to execute DML scripts (if different).
spring.datasource.data-password= # Password of the database to execute DML scripts (if different).
spring.datasource.dbcp2.*= # Commons DBCP2 specific settings
spring.datasource.driver-class-name= # Fully qualified name of the JDBC driver. Auto-detected based on the URL by default.
spring.datasource.generate-unique-name=false # Whether to generate a random datasource name.
spring.datasource.hikari.*= # Hikari specific settings
spring.datasource.initialization-mode=embedded # Initialize the datasource with available DDL and DML scripts.
spring.datasource.jmx-enabled=false # Whether to enable JMX support (if provided by the underlying pool).
spring.datasource.jndi-name= # JNDI location of the datasource. Class, url, username & password are ignored when set.
spring.datasource.name= # Name of the datasource. Default to "testdb" when using an embedded database.
spring.datasource.password= # Login password of the database.
spring.datasource.platform=all # Platform to use in the DDL or DML scripts (such as schema-${platform}.sql or data-${platform}
spring.datasource.schema= # Schema (DDL) script resource references.
spring.datasource.schema-username= # Username of the database to execute DDL scripts (if different).
spring.datasource.schema-password= # Password of the database to execute DDL scripts (if different).
spring.datasource.separator=; # Statement separator in SQL initialization scripts.
spring.datasource.sql-script-encoding= # SQL scripts encoding.
spring.datasource.tomcat.*= # Tomcat datasource specific settings
spring.datasource.type= # Fully qualified name of the connection pool implementation to use. By default, it is auto-detected f
spring.datasource.url= # JDBC URL of the database.
spring.datasource.username= # Login username of the database.
spring.datasource.xa.data-source-class-name= # XA datasource fully qualified name.
spring.datasource.xa.properties= # Properties to pass to the XA data source.
# JEST (Elasticsearch HTTP client) (JestProperties)
spring.elasticsearch.jest.connection-timeout=3s # Connection timeout.
spring.elasticsearch.jest.multi-threaded=true # Whether to enable connection requests from multiple execution threads.
spring.elasticsearch.jest.password= # Login password.
spring.elasticsearch.jest.proxy.host= # Proxy host the HTTP client should use.
spring.elasticsearch.jest.proxy.port= # Proxy port the HTTP client should use.
spring.elasticsearch.jest.read-timeout=3s # Read timeout.
spring.elasticsearch.jest.uris=http://localhost:9200 # Comma-separated list of the Elasticsearch instances to use.
spring.elasticsearch.jest.username= # Login username.
# Elasticsearch REST clients (RestClientProperties)
spring.elasticsearch.rest.password= # Credentials password.
spring.elasticsearch.rest.uris=http://localhost:9200 # Comma-separated list of the Elasticsearch instances to use.
spring.elasticsearch.rest.username= # Credentials username.
# H2 Web Console (H2ConsoleProperties)

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spring.h2.console.enabled=false # Whether to enable the console.
spring.h2.console.path=/h2-console # Path at which the console is available.
spring.h2.console.settings.trace=false # Whether to enable trace output.
spring.h2.console.settings.web-allow-others=false # Whether to enable remote access.
# InfluxDB (InfluxDbProperties)
spring.influx.password= # Login password.
spring.influx.url= # URL of the InfluxDB instance to which to connect.
spring.influx.user= # Login user.
# JOOQ (JooqProperties)
spring.jooq.sql-dialect= # SQL dialect to use. Auto-detected by default.
# JDBC (JdbcProperties)
spring.jdbc.template.fetch-size=-1 # Number of rows that should be fetched from the database when more rows are needed.
spring.jdbc.template.max-rows=-1 # Maximum number of rows.
spring.jdbc.template.query-timeout= # Query timeout. Default is to use the JDBC driver's default configuration. If a duration
# JPA (JpaBaseConfiguration, HibernateJpaAutoConfiguration)
spring.data.jpa.repositories.bootstrap-mode=default # Bootstrap mode for JPA repositories.
spring.data.jpa.repositories.enabled=true # Whether to enable JPA repositories.
spring.jpa.database= # Target database to operate on, auto-detected by default. Can be alternatively set using the "databasePl
spring.jpa.database-platform= # Name of the target database to operate on, auto-detected by default. Can be alternatively set
spring.jpa.generate-ddl=false # Whether to initialize the schema on startup.
spring.jpa.hibernate.ddl-auto= # DDL mode. This is actually a shortcut for the "hibernate.hbm2ddl.auto" property. Defaults to
spring.jpa.hibernate.naming.implicit-strategy= # Fully qualified name of the implicit naming strategy.
spring.jpa.hibernate.naming.physical-strategy= # Fully qualified name of the physical naming strategy.
spring.jpa.hibernate.use-new-id-generator-mappings= # Whether to use Hibernate's newer IdentifierGenerator for AUTO, TABLE and
spring.jpa.mapping-resources= # Mapping resources (equivalent to "mapping-file" entries in persistence.xml).
spring.jpa.open-in-view=true # Register OpenEntityManagerInViewInterceptor. Binds a JPA EntityManager to the thread for the en
spring.jpa.properties.*= # Additional native properties to set on the JPA provider.
spring.jpa.show-sql=false # Whether to enable logging of SQL statements.
# JTA (JtaAutoConfiguration)
spring.jta.enabled=true # Whether to enable JTA support.
spring.jta.log-dir= # Transaction logs directory.
spring.jta.transaction-manager-id= # Transaction manager unique identifier.
# ATOMIKOS (AtomikosProperties)
spring.jta.atomikos.connectionfactory.borrow-connection-timeout=30 # Timeout, in seconds, for borrowing connections from the p
spring.jta.atomikos.connectionfactory.ignore-session-transacted-flag=true # Whether to ignore the transacted flag when creatin
spring.jta.atomikos.connectionfactory.local-transaction-mode=false # Whether local transactions are desired.
spring.jta.atomikos.connectionfactory.maintenance-interval=60 # The time, in seconds, between runs of the pool's maintenance t
spring.jta.atomikos.connectionfactory.max-idle-time=60 # The time, in seconds, after which connections are cleaned up from the
spring.jta.atomikos.connectionfactory.max-lifetime=0 # The time, in seconds, that a connection can be pooled for before being
spring.jta.atomikos.connectionfactory.max-pool-size=1 # The maximum size of the pool.
spring.jta.atomikos.connectionfactory.min-pool-size=1 # The minimum size of the pool.
spring.jta.atomikos.connectionfactory.reap-timeout=0 # The reap timeout, in seconds, for borrowed connections. 0 denotes no li
spring.jta.atomikos.connectionfactory.unique-resource-name=jmsConnectionFactory # The unique name used to identify the resourc
spring.jta.atomikos.connectionfactory.xa-connection-factory-class-name= # Vendor-specific implementation of XAConnectionFactor
spring.jta.atomikos.connectionfactory.xa-properties= # Vendor-specific XA properties.
spring.jta.atomikos.datasource.borrow-connection-timeout=30 # Timeout, in seconds, for borrowing connections from the pool.
spring.jta.atomikos.datasource.concurrent-connection-validation= # Whether to use concurrent connection validation.
spring.jta.atomikos.datasource.default-isolation-level= # Default isolation level of connections provided by the pool.
spring.jta.atomikos.datasource.login-timeout= # Timeout, in seconds, for establishing a database connection.
spring.jta.atomikos.datasource.maintenance-interval=60 # The time, in seconds, between runs of the pool's maintenance thread.
spring.jta.atomikos.datasource.max-idle-time=60 # The time, in seconds, after which connections are cleaned up from the pool.
spring.jta.atomikos.datasource.max-lifetime=0 # The time, in seconds, that a connection can be pooled for before being destroy
spring.jta.atomikos.datasource.max-pool-size=1 # The maximum size of the pool.
spring.jta.atomikos.datasource.min-pool-size=1 # The minimum size of the pool.
spring.jta.atomikos.datasource.reap-timeout=0 # The reap timeout, in seconds, for borrowed connections. 0 denotes no limit.
spring.jta.atomikos.datasource.test-query= # SQL query or statement used to validate a connection before returning it.
spring.jta.atomikos.datasource.unique-resource-name=dataSource # The unique name used to identify the resource during recovery
spring.jta.atomikos.datasource.xa-data-source-class-name= # Vendor-specific implementation of XAConnectionFactory.
spring.jta.atomikos.datasource.xa-properties= # Vendor-specific XA properties.
spring.jta.atomikos.properties.allow-sub-transactions=true # Specify whether sub-transactions are allowed.
spring.jta.atomikos.properties.checkpoint-interval=500 # Interval between checkpoints, expressed as the number of log writes b
spring.jta.atomikos.properties.default-jta-timeout=10000ms # Default timeout for JTA transactions.
spring.jta.atomikos.properties.default-max-wait-time-on-shutdown=9223372036854775807 # How long should normal shutdown (no-for
spring.jta.atomikos.properties.enable-logging=true # Whether to enable disk logging.

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spring.jta.atomikos.properties.force-shutdown-on-vm-exit=false # Whether a VM shutdown should trigger forced shutdown of the t
spring.jta.atomikos.properties.log-base-dir= # Directory in which the log files should be stored.
spring.jta.atomikos.properties.log-base-name=tmlog # Transactions log file base name.
spring.jta.atomikos.properties.max-actives=50 # Maximum number of active transactions.
spring.jta.atomikos.properties.max-timeout=300000ms # Maximum timeout that can be allowed for transactions.
spring.jta.atomikos.properties.recovery.delay=10000ms # Delay between two recovery scans.
spring.jta.atomikos.properties.recovery.forget-orphaned-log-entries-delay=86400000ms # Delay after which recovery can cleanup
spring.jta.atomikos.properties.recovery.max-retries=5 # Number of retry attempts to commit the transaction before throwing an
spring.jta.atomikos.properties.recovery.retry-interval=10000ms # Delay between retry attempts.
spring.jta.atomikos.properties.serial-jta-transactions=true # Whether sub-transactions should be joined when possible.
spring.jta.atomikos.properties.service= # Transaction manager implementation that should be started.
spring.jta.atomikos.properties.threaded-two-phase-commit=false # Whether to use different (and concurrent) threads for two-pha
spring.jta.atomikos.properties.transaction-manager-unique-name= # The transaction manager's unique name.
# BITRONIX
spring.jta.bitronix.connectionfactory.acquire-increment=1 # Number of connections to create when growing the pool.
spring.jta.bitronix.connectionfactory.acquisition-interval=1 # Time, in seconds, to wait before trying to acquire a connection
spring.jta.bitronix.connectionfactory.acquisition-timeout=30 # Timeout, in seconds, for acquiring connections from the pool.
spring.jta.bitronix.connectionfactory.allow-local-transactions=true # Whether the transaction manager should allow mixing XA a
spring.jta.bitronix.connectionfactory.apply-transaction-timeout=false # Whether the transaction timeout should be set on the X
spring.jta.bitronix.connectionfactory.automatic-enlisting-enabled=true # Whether resources should be enlisted and delisted aut
spring.jta.bitronix.connectionfactory.cache-producers-consumers=true # Whether producers and consumers should be cached.
spring.jta.bitronix.connectionfactory.class-name= # Underlying implementation class name of the XA resource.
spring.jta.bitronix.connectionfactory.defer-connection-release=true # Whether the provider can run many transactions on the sa
spring.jta.bitronix.connectionfactory.disabled= # Whether this resource is disabled, meaning it's temporarily forbidden to acq
spring.jta.bitronix.connectionfactory.driver-properties= # Properties that should be set on the underlying implementation.
spring.jta.bitronix.connectionfactory.failed= # Mark this resource producer as failed.
spring.jta.bitronix.connectionfactory.ignore-recovery-failures=false # Whether recovery failures should be ignored.
spring.jta.bitronix.connectionfactory.max-idle-time=60 # The time, in seconds, after which connections are cleaned up from the
spring.jta.bitronix.connectionfactory.max-pool-size=10 # The maximum size of the pool. 0 denotes no limit.
spring.jta.bitronix.connectionfactory.min-pool-size=0 # The minimum size of the pool.
spring.jta.bitronix.connectionfactory.password= # The password to use to connect to the JMS provider.
spring.jta.bitronix.connectionfactory.share-transaction-connections=false # Whether connections in the ACCESSIBLE state can b
spring.jta.bitronix.connectionfactory.test-connections=true # Whether connections should be tested when acquired from the pool
spring.jta.bitronix.connectionfactory.two-pc-ordering-position=1 # The position that this resource should take during two-phas
spring.jta.bitronix.connectionfactory.unique-name=jmsConnectionFactory # The unique name used to identify the resource during
spring.jta.bitronix.connectionfactory.use-tm-join=true # Whether TMJOIN should be used when starting XAResources.
spring.jta.bitronix.connectionfactory.user= # The user to use to connect to the JMS provider.
spring.jta.bitronix.datasource.acquire-increment=1 # Number of connections to create when growing the pool.
spring.jta.bitronix.datasource.acquisition-interval=1 # Time, in seconds, to wait before trying to acquire a connection again
spring.jta.bitronix.datasource.acquisition-timeout=30 # Timeout, in seconds, for acquiring connections from the pool.
spring.jta.bitronix.datasource.allow-local-transactions=true # Whether the transaction manager should allow mixing XA and nonspring.jta.bitronix.datasource.apply-transaction-timeout=false # Whether the transaction timeout should be set on the XAResour
spring.jta.bitronix.datasource.automatic-enlisting-enabled=true # Whether resources should be enlisted and delisted automatica
spring.jta.bitronix.datasource.class-name= # Underlying implementation class name of the XA resource.
spring.jta.bitronix.datasource.cursor-holdability= # The default cursor holdability for connections.
spring.jta.bitronix.datasource.defer-connection-release=true # Whether the database can run many transactions on the same conn
spring.jta.bitronix.datasource.disabled= # Whether this resource is disabled, meaning it's temporarily forbidden to acquire a
spring.jta.bitronix.datasource.driver-properties= # Properties that should be set on the underlying implementation.
spring.jta.bitronix.datasource.enable-jdbc4-connection-test= # Whether Connection.isValid() is called when acquiring a connect
spring.jta.bitronix.datasource.failed= # Mark this resource producer as failed.
spring.jta.bitronix.datasource.ignore-recovery-failures=false # Whether recovery failures should be ignored.
spring.jta.bitronix.datasource.isolation-level= # The default isolation level for connections.
spring.jta.bitronix.datasource.local-auto-commit= # The default auto-commit mode for local transactions.
spring.jta.bitronix.datasource.login-timeout= # Timeout, in seconds, for establishing a database connection.
spring.jta.bitronix.datasource.max-idle-time=60 # The time, in seconds, after which connections are cleaned up from the pool.
spring.jta.bitronix.datasource.max-pool-size=10 # The maximum size of the pool. 0 denotes no limit.
spring.jta.bitronix.datasource.min-pool-size=0 # The minimum size of the pool.
spring.jta.bitronix.datasource.prepared-statement-cache-size=0 # The target size of the prepared statement cache. 0 disables t
spring.jta.bitronix.datasource.share-transaction-connections=false # Whether connections in the ACCESSIBLE state can be share
spring.jta.bitronix.datasource.test-query= # SQL query or statement used to validate a connection before returning it.
spring.jta.bitronix.datasource.two-pc-ordering-position=1 # The position that this resource should take during two-phase commi
spring.jta.bitronix.datasource.unique-name=dataSource # The unique name used to identify the resource during recovery.
spring.jta.bitronix.datasource.use-tm-join=true # Whether TMJOIN should be used when starting XAResources.
spring.jta.bitronix.properties.allow-multiple-lrc=false # Whether to allow multiple LRC resources to be enlisted into the same
spring.jta.bitronix.properties.asynchronous2-pc=false # Whether to enable asynchronously execution of two phase commit.
spring.jta.bitronix.properties.background-recovery-interval-seconds=60 # Interval in seconds at which to run the recovery proc
spring.jta.bitronix.properties.current-node-only-recovery=true # Whether to recover only the current node.
spring.jta.bitronix.properties.debug-zero-resource-transaction=false # Whether to log the creation and commit call stacks of t
spring.jta.bitronix.properties.default-transaction-timeout=60 # Default transaction timeout, in seconds.

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spring.jta.bitronix.properties.disable-jmx=false # Whether to enable JMX support.
spring.jta.bitronix.properties.exception-analyzer= # Set the fully qualified name of the exception analyzer implementation to
spring.jta.bitronix.properties.filter-log-status=false # Whether to enable filtering of logs so that only mandatory logs are w
spring.jta.bitronix.properties.force-batching-enabled=true # Whether disk forces are batched.
spring.jta.bitronix.properties.forced-write-enabled=true # Whether logs are forced to disk.
spring.jta.bitronix.properties.graceful-shutdown-interval=60 # Maximum amount of seconds the TM waits for transactions to get
spring.jta.bitronix.properties.jndi-transaction-synchronization-registry-name= # JNDI name of the TransactionSynchronizationRe
spring.jta.bitronix.properties.jndi-user-transaction-name= # JNDI name of the UserTransaction.
spring.jta.bitronix.properties.journal=disk # Name of the journal. Can be 'disk', 'null', or a class name.
spring.jta.bitronix.properties.log-part1-filename=btm1.tlog # Name of the first fragment of the journal.
spring.jta.bitronix.properties.log-part2-filename=btm2.tlog # Name of the second fragment of the journal.
spring.jta.bitronix.properties.max-log-size-in-mb=2 # Maximum size in megabytes of the journal fragments.
spring.jta.bitronix.properties.resource-configuration-filename= # ResourceLoader configuration file name.
spring.jta.bitronix.properties.server-id= # ASCII ID that must uniquely identify this TM instance. Defaults to the machine's I
spring.jta.bitronix.properties.skip-corrupted-logs=false # Skip corrupted transactions log entries.
spring.jta.bitronix.properties.warn-about-zero-resource-transaction=true # Whether to log a warning for transactions executed
# EMBEDDED MONGODB (EmbeddedMongoProperties)
spring.mongodb.embedded.features=sync_delay # Comma-separated list of features to enable.
spring.mongodb.embedded.storage.database-dir= # Directory used for data storage.
spring.mongodb.embedded.storage.oplog-size= # Maximum size of the oplog.
spring.mongodb.embedded.storage.repl-set-name= # Name of the replica set.
spring.mongodb.embedded.version=3.5.5 # Version of Mongo to use.
# REDIS (RedisProperties)
spring.redis.cluster.max-redirects= # Maximum number of redirects to follow when executing commands across the cluster.
spring.redis.cluster.nodes= # Comma-separated list of "host:port" pairs to bootstrap from.
spring.redis.database=0 # Database index used by the connection factory.
spring.redis.url= # Connection URL. Overrides host, port, and password. User is ignored. Example: redis://user:password@exampl
spring.redis.host=localhost # Redis server host.
spring.redis.jedis.pool.max-active=8 # Maximum number of connections that can be allocated by the pool at a given time. Use a
spring.redis.jedis.pool.max-idle=8 # Maximum number of "idle" connections in the pool. Use a negative value to indicate an unl
spring.redis.jedis.pool.max-wait=-1ms # Maximum amount of time a connection allocation should block before throwing an excepti
spring.redis.jedis.pool.min-idle=0 # Target for the minimum number of idle connections to maintain in the pool. This setting o
spring.redis.lettuce.pool.max-active=8 # Maximum number of connections that can be allocated by the pool at a given time. Use
spring.redis.lettuce.pool.max-idle=8 # Maximum number of "idle" connections in the pool. Use a negative value to indicate an u
spring.redis.lettuce.pool.max-wait=-1ms # Maximum amount of time a connection allocation should block before throwing an excep
spring.redis.lettuce.pool.min-idle=0 # Target for the minimum number of idle connections to maintain in the pool. This setting
spring.redis.lettuce.shutdown-timeout=100ms # Shutdown timeout.
spring.redis.password= # Login password of the redis server.
spring.redis.port=6379 # Redis server port.
spring.redis.sentinel.master= # Name of the Redis server.
spring.redis.sentinel.nodes= # Comma-separated list of "host:port" pairs.
spring.redis.ssl=false # Whether to enable SSL support.
spring.redis.timeout= # Connection timeout.
# TRANSACTION (TransactionProperties)
spring.transaction.default-timeout= # Default transaction timeout. If a duration suffix is not specified, seconds will be used
spring.transaction.rollback-on-commit-failure= # Whether to roll back on commit failures.

# ---------------------------------------# INTEGRATION PROPERTIES
# ---------------------------------------# ACTIVEMQ (ActiveMQProperties)
spring.activemq.broker-url= # URL of the ActiveMQ broker. Auto-generated by default.
spring.activemq.close-timeout=15s # Time to wait before considering a close complete.
spring.activemq.in-memory=true # Whether the default broker URL should be in memory. Ignored if an explicit broker has been sp
spring.activemq.non-blocking-redelivery=false # Whether to stop message delivery before re-delivering messages from a rolled b
spring.activemq.password= # Login password of the broker.
spring.activemq.send-timeout=0ms # Time to wait on message sends for a response. Set it to 0 to wait forever.
spring.activemq.user= # Login user of the broker.
spring.activemq.packages.trust-all= # Whether to trust all packages.
spring.activemq.packages.trusted= # Comma-separated list of specific packages to trust (when not trusting all packages).
spring.activemq.pool.block-if-full=true # Whether to block when a connection is requested and the pool is full. Set it to fals
spring.activemq.pool.block-if-full-timeout=-1ms # Blocking period before throwing an exception if the pool is still full.
spring.activemq.pool.enabled=false # Whether a JmsPoolConnectionFactory should be created, instead of a regular ConnectionFact
spring.activemq.pool.idle-timeout=30s # Connection idle timeout.

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spring.activemq.pool.max-connections=1 # Maximum number of pooled connections.
spring.activemq.pool.max-sessions-per-connection=500 # Maximum number of pooled sessions per connection in the pool.
spring.activemq.pool.time-between-expiration-check=-1ms # Time to sleep between runs of the idle connection eviction thread. W
spring.activemq.pool.use-anonymous-producers=true # Whether to use only one anonymous "MessageProducer" instance. Set it to fa
# ARTEMIS (ArtemisProperties)
spring.artemis.embedded.cluster-password= # Cluster password. Randomly generated on startup by default.
spring.artemis.embedded.data-directory= # Journal file directory. Not necessary if persistence is turned off.
spring.artemis.embedded.enabled=true # Whether to enable embedded mode if the Artemis server APIs are available.
spring.artemis.embedded.persistent=false # Whether to enable persistent store.
spring.artemis.embedded.queues= # Comma-separated list of queues to create on startup.
spring.artemis.embedded.server-id= # Server ID. By default, an auto-incremented counter is used.
spring.artemis.embedded.topics= # Comma-separated list of topics to create on startup.
spring.artemis.host=localhost # Artemis broker host.
spring.artemis.mode= # Artemis deployment mode, auto-detected by default.
spring.artemis.password= # Login password of the broker.
spring.artemis.pool.block-if-full=true # Whether to block when a connection is requested and the pool is full. Set it to false
spring.artemis.pool.block-if-full-timeout=-1ms # Blocking period before throwing an exception if the pool is still full.
spring.artemis.pool.enabled=false # Whether a JmsPoolConnectionFactory should be created, instead of a regular ConnectionFacto
spring.artemis.pool.idle-timeout=30s # Connection idle timeout.
spring.artemis.pool.max-connections=1 # Maximum number of pooled connections.
spring.artemis.pool.max-sessions-per-connection=500 # Maximum number of pooled sessions per connection in the pool.
spring.artemis.pool.time-between-expiration-check=-1ms # Time to sleep between runs of the idle connection eviction thread. Wh
spring.artemis.pool.use-anonymous-producers=true # Whether to use only one anonymous "MessageProducer" instance. Set it to fal
spring.artemis.port=61616 # Artemis broker port.
spring.artemis.user= # Login user of the broker.
# SPRING BATCH (BatchProperties)
spring.batch.initialize-schema=embedded # Database schema initialization mode.
spring.batch.job.enabled=true # Execute all Spring Batch jobs in the context on startup.
spring.batch.job.names= # Comma-separated list of job names to execute on startup (for instance, `job1,job2`). By default, all
spring.batch.schema=classpath:org/springframework/batch/core/schema-@@platform@@.sql # Path to the SQL file to use to initiali
spring.batch.table-prefix= # Table prefix for all the batch meta-data tables.
# SPRING INTEGRATION (IntegrationProperties)
spring.integration.jdbc.initialize-schema=embedded # Database schema initialization mode.
spring.integration.jdbc.schema=classpath:org/springframework/integration/jdbc/schema-@@platform@@.sql # Path to the SQL file t
# JMS (JmsProperties)
spring.jms.cache.consumers=false # Whether to cache message consumers.
spring.jms.cache.enabled=true # Whether to cache sessions.
spring.jms.cache.producers=true # Whether to cache message producers.
spring.jms.cache.session-cache-size=1 # Size of the session cache (per JMS Session type).
spring.jms.jndi-name= # Connection factory JNDI name. When set, takes precedence to others connection factory auto-configurati
spring.jms.listener.acknowledge-mode= # Acknowledge mode of the container. By default, the listener is transacted with automat
spring.jms.listener.auto-startup=true # Start the container automatically on startup.
spring.jms.listener.concurrency= # Minimum number of concurrent consumers.
spring.jms.listener.max-concurrency= # Maximum number of concurrent consumers.
spring.jms.pub-sub-domain=false # Whether the default destination type is topic.
spring.jms.template.default-destination= # Default destination to use on send and receive operations that do not have a destin
spring.jms.template.delivery-delay= # Delivery delay to use for send calls.
spring.jms.template.delivery-mode= # Delivery mode. Enables QoS (Quality of Service) when set.
spring.jms.template.priority= # Priority of a message when sending. Enables QoS (Quality of Service) when set.
spring.jms.template.qos-enabled= # Whether to enable explicit QoS (Quality of Service) when sending a message.
spring.jms.template.receive-timeout= # Timeout to use for receive calls.
spring.jms.template.time-to-live= # Time-to-live of a message when sending. Enables QoS (Quality of Service) when set.
# APACHE KAFKA (KafkaProperties)
spring.kafka.admin.client-id= # ID to pass to the server when making requests. Used for server-side logging.
spring.kafka.admin.fail-fast=false # Whether to fail fast if the broker is not available on startup.
spring.kafka.admin.properties.*= # Additional admin-specific properties used to configure the client.
spring.kafka.admin.ssl.key-password= # Password of the private key in the key store file.
spring.kafka.admin.ssl.key-store-location= # Location of the key store file.
spring.kafka.admin.ssl.key-store-password= # Store password for the key store file.
spring.kafka.admin.ssl.key-store-type= # Type of the key store.
spring.kafka.admin.ssl.protocol= # SSL protocol to use.
spring.kafka.admin.ssl.trust-store-location= # Location of the trust store file.
spring.kafka.admin.ssl.trust-store-password= # Store password for the trust store file.
spring.kafka.admin.ssl.trust-store-type= # Type of the trust store.
spring.kafka.bootstrap-servers= # Comma-delimited list of host:port pairs to use for establishing the initial connections to t

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spring.kafka.client-id= # ID to pass to the server when making requests. Used for server-side logging.
spring.kafka.consumer.auto-commit-interval= # Frequency with which the consumer offsets are auto-committed to Kafka if 'enable
spring.kafka.consumer.auto-offset-reset= # What to do when there is no initial offset in Kafka or if the current offset no lon
spring.kafka.consumer.bootstrap-servers= # Comma-delimited list of host:port pairs to use for establishing the initial connect
spring.kafka.consumer.client-id= # ID to pass to the server when making requests. Used for server-side logging.
spring.kafka.consumer.enable-auto-commit= # Whether the consumer's offset is periodically committed in the background.
spring.kafka.consumer.fetch-max-wait= # Maximum amount of time the server blocks before answering the fetch request if there i
spring.kafka.consumer.fetch-min-size= # Minimum amount of data the server should return for a fetch request.
spring.kafka.consumer.group-id= # Unique string that identifies the consumer group to which this consumer belongs.
spring.kafka.consumer.heartbeat-interval= # Expected time between heartbeats to the consumer coordinator.
spring.kafka.consumer.key-deserializer= # Deserializer class for keys.
spring.kafka.consumer.max-poll-records= # Maximum number of records returned in a single call to poll().
spring.kafka.consumer.properties.*= # Additional consumer-specific properties used to configure the client.
spring.kafka.consumer.ssl.key-password= # Password of the private key in the key store file.
spring.kafka.consumer.ssl.key-store-location= # Location of the key store file.
spring.kafka.consumer.ssl.key-store-password= # Store password for the key store file.
spring.kafka.consumer.ssl.key-store-type= # Type of the key store.
spring.kafka.consumer.ssl.protocol= # SSL protocol to use.
spring.kafka.consumer.ssl.trust-store-location= # Location of the trust store file.
spring.kafka.consumer.ssl.trust-store-password= # Store password for the trust store file.
spring.kafka.consumer.ssl.trust-store-type= # Type of the trust store.
spring.kafka.consumer.value-deserializer= # Deserializer class for values.
spring.kafka.jaas.control-flag=required # Control flag for login configuration.
spring.kafka.jaas.enabled=false # Whether to enable JAAS configuration.
spring.kafka.jaas.login-module=com.sun.security.auth.module.Krb5LoginModule # Login module.
spring.kafka.jaas.options= # Additional JAAS options.
spring.kafka.listener.ack-count= # Number of records between offset commits when ackMode is "COUNT" or "COUNT_TIME".
spring.kafka.listener.ack-mode= # Listener AckMode. See the spring-kafka documentation.
spring.kafka.listener.ack-time= # Time between offset commits when ackMode is "TIME" or "COUNT_TIME".
spring.kafka.listener.client-id= # Prefix for the listener's consumer client.id property.
spring.kafka.listener.concurrency= # Number of threads to run in the listener containers.
spring.kafka.listener.idle-event-interval= # Time between publishing idle consumer events (no data received).
spring.kafka.listener.log-container-config= # Whether to log the container configuration during initialization (INFO level).
spring.kafka.listener.monitor-interval= # Time between checks for non-responsive consumers. If a duration suffix is not specif
spring.kafka.listener.no-poll-threshold= # Multiplier applied to "pollTimeout" to determine if a consumer is non-responsive.
spring.kafka.listener.poll-timeout= # Timeout to use when polling the consumer.
spring.kafka.listener.type=single # Listener type.
spring.kafka.producer.acks= # Number of acknowledgments the producer requires the leader to have received before considering a
spring.kafka.producer.batch-size= # Default batch size.
spring.kafka.producer.bootstrap-servers= # Comma-delimited list of host:port pairs to use for establishing the initial connect
spring.kafka.producer.buffer-memory= # Total memory size the producer can use to buffer records waiting to be sent to the serv
spring.kafka.producer.client-id= # ID to pass to the server when making requests. Used for server-side logging.
spring.kafka.producer.compression-type= # Compression type for all data generated by the producer.
spring.kafka.producer.key-serializer= # Serializer class for keys.
spring.kafka.producer.properties.*= # Additional producer-specific properties used to configure the client.
spring.kafka.producer.retries= # When greater than zero, enables retrying of failed sends.
spring.kafka.producer.ssl.key-password= # Password of the private key in the key store file.
spring.kafka.producer.ssl.key-store-location= # Location of the key store file.
spring.kafka.producer.ssl.key-store-password= # Store password for the key store file.
spring.kafka.producer.ssl.key-store-type= # Type of the key store.
spring.kafka.producer.ssl.protocol= # SSL protocol to use.
spring.kafka.producer.ssl.trust-store-location= # Location of the trust store file.
spring.kafka.producer.ssl.trust-store-password= # Store password for the trust store file.
spring.kafka.producer.ssl.trust-store-type= # Type of the trust store.
spring.kafka.producer.transaction-id-prefix= # When non empty, enables transaction support for producer.
spring.kafka.producer.value-serializer= # Serializer class for values.
spring.kafka.properties.*= # Additional properties, common to producers and consumers, used to configure the client.
spring.kafka.ssl.key-password= # Password of the private key in the key store file.
spring.kafka.ssl.key-store-location= # Location of the key store file.
spring.kafka.ssl.key-store-password= # Store password for the key store file.
spring.kafka.ssl.key-store-type= # Type of the key store.
spring.kafka.ssl.protocol= # SSL protocol to use.
spring.kafka.ssl.trust-store-location= # Location of the trust store file.
spring.kafka.ssl.trust-store-password= # Store password for the trust store file.
spring.kafka.ssl.trust-store-type= # Type of the trust store.
spring.kafka.streams.application-id= # Kafka streams application.id property; default spring.application.name.
spring.kafka.streams.auto-startup=true # Whether or not to auto-start the streams factory bean.
spring.kafka.streams.bootstrap-servers= # Comma-delimited list of host:port pairs to use for establishing the initial connecti
spring.kafka.streams.cache-max-size-buffering= # Maximum memory size to be used for buffering across all threads.
spring.kafka.streams.client-id= # ID to pass to the server when making requests. Used for server-side logging.

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spring.kafka.streams.properties.*= # Additional Kafka properties used to configure the streams.
spring.kafka.streams.replication-factor= # The replication factor for change log topics and repartition topics created by the
spring.kafka.streams.ssl.key-password= # Password of the private key in the key store file.
spring.kafka.streams.ssl.key-store-location= # Location of the key store file.
spring.kafka.streams.ssl.key-store-password= # Store password for the key store file.
spring.kafka.streams.ssl.key-store-type= # Type of the key store.
spring.kafka.streams.ssl.protocol= # SSL protocol to use.
spring.kafka.streams.ssl.trust-store-location= # Location of the trust store file.
spring.kafka.streams.ssl.trust-store-password= # Store password for the trust store file.
spring.kafka.streams.ssl.trust-store-type= # Type of the trust store.
spring.kafka.streams.state-dir= # Directory location for the state store.
spring.kafka.template.default-topic= # Default topic to which messages are sent.
# RABBIT (RabbitProperties)
spring.rabbitmq.addresses= # Comma-separated list of addresses to which the client should connect.
spring.rabbitmq.cache.channel.checkout-timeout= # Duration to wait to obtain a channel if the cache size has been reached.
spring.rabbitmq.cache.channel.size= # Number of channels to retain in the cache.
spring.rabbitmq.cache.connection.mode=channel # Connection factory cache mode.
spring.rabbitmq.cache.connection.size= # Number of connections to cache.
spring.rabbitmq.connection-timeout= # Connection timeout. Set it to zero to wait forever.
spring.rabbitmq.dynamic=true # Whether to create an AmqpAdmin bean.
spring.rabbitmq.host=localhost # RabbitMQ host.
spring.rabbitmq.listener.direct.acknowledge-mode= # Acknowledge mode of container.
spring.rabbitmq.listener.direct.auto-startup=true # Whether to start the container automatically on startup.
spring.rabbitmq.listener.direct.consumers-per-queue= # Number of consumers per queue.
spring.rabbitmq.listener.direct.default-requeue-rejected= # Whether rejected deliveries are re-queued by default.
spring.rabbitmq.listener.direct.idle-event-interval= # How often idle container events should be published.
spring.rabbitmq.listener.direct.missing-queues-fatal=false # Whether to fail if the queues declared by the container are not a
spring.rabbitmq.listener.direct.prefetch= # Maximum number of unacknowledged messages that can be outstanding at each consumer
spring.rabbitmq.listener.direct.retry.enabled=false # Whether publishing retries are enabled.
spring.rabbitmq.listener.direct.retry.initial-interval=1000ms # Duration between the first and second attempt to deliver a mes
spring.rabbitmq.listener.direct.retry.max-attempts=3 # Maximum number of attempts to deliver a message.
spring.rabbitmq.listener.direct.retry.max-interval=10000ms # Maximum duration between attempts.
spring.rabbitmq.listener.direct.retry.multiplier=1 # Multiplier to apply to the previous retry interval.
spring.rabbitmq.listener.direct.retry.stateless=true # Whether retries are stateless or stateful.
spring.rabbitmq.listener.simple.acknowledge-mode= # Acknowledge mode of container.
spring.rabbitmq.listener.simple.auto-startup=true # Whether to start the container automatically on startup.
spring.rabbitmq.listener.simple.concurrency= # Minimum number of listener invoker threads.
spring.rabbitmq.listener.simple.default-requeue-rejected= # Whether rejected deliveries are re-queued by default.
spring.rabbitmq.listener.simple.idle-event-interval= # How often idle container events should be published.
spring.rabbitmq.listener.simple.max-concurrency= # Maximum number of listener invoker threads.
spring.rabbitmq.listener.simple.missing-queues-fatal=true # Whether to fail if the queues declared by the container are not av
spring.rabbitmq.listener.simple.prefetch= # Maximum number of unacknowledged messages that can be outstanding at each consumer
spring.rabbitmq.listener.simple.retry.enabled=false # Whether publishing retries are enabled.
spring.rabbitmq.listener.simple.retry.initial-interval=1000ms # Duration between the first and second attempt to deliver a mes
spring.rabbitmq.listener.simple.retry.max-attempts=3 # Maximum number of attempts to deliver a message.
spring.rabbitmq.listener.simple.retry.max-interval=10000ms # Maximum duration between attempts.
spring.rabbitmq.listener.simple.retry.multiplier=1 # Multiplier to apply to the previous retry interval.
spring.rabbitmq.listener.simple.retry.stateless=true # Whether retries are stateless or stateful.
spring.rabbitmq.listener.simple.transaction-size= # Number of messages to be processed between acks when the acknowledge mode
spring.rabbitmq.listener.type=simple # Listener container type.
spring.rabbitmq.password=guest # Login to authenticate against the broker.
spring.rabbitmq.port=5672 # RabbitMQ port.
spring.rabbitmq.publisher-confirms=false # Whether to enable publisher confirms.
spring.rabbitmq.publisher-returns=false # Whether to enable publisher returns.
spring.rabbitmq.requested-heartbeat= # Requested heartbeat timeout; zero for none. If a duration suffix is not specified, seco
spring.rabbitmq.ssl.algorithm= # SSL algorithm to use. By default, configured by the Rabbit client library.
spring.rabbitmq.ssl.enabled=false # Whether to enable SSL support.
spring.rabbitmq.ssl.key-store= # Path to the key store that holds the SSL certificate.
spring.rabbitmq.ssl.key-store-password= # Password used to access the key store.
spring.rabbitmq.ssl.key-store-type=PKCS12 # Key store type.
spring.rabbitmq.ssl.trust-store= # Trust store that holds SSL certificates.
spring.rabbitmq.ssl.trust-store-password= # Password used to access the trust store.
spring.rabbitmq.ssl.trust-store-type=JKS # Trust store type.
spring.rabbitmq.ssl.validate-server-certificate=true # Whether to enable server side certificate validation.
spring.rabbitmq.ssl.verify-hostname=true # Whether to enable hostname verification.
spring.rabbitmq.template.default-receive-queue= # Name of the default queue to receive messages from when none is specified ex
spring.rabbitmq.template.exchange= # Name of the default exchange to use for send operations.
spring.rabbitmq.template.mandatory= # Whether to enable mandatory messages.
spring.rabbitmq.template.receive-timeout= # Timeout for `receive()` operations.

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spring.rabbitmq.template.reply-timeout= # Timeout for `sendAndReceive()` operations.
spring.rabbitmq.template.retry.enabled=false # Whether publishing retries are enabled.
spring.rabbitmq.template.retry.initial-interval=1000ms # Duration between the first and second attempt to deliver a message.
spring.rabbitmq.template.retry.max-attempts=3 # Maximum number of attempts to deliver a message.
spring.rabbitmq.template.retry.max-interval=10000ms # Maximum duration between attempts.
spring.rabbitmq.template.retry.multiplier=1 # Multiplier to apply to the previous retry interval.
spring.rabbitmq.template.routing-key= # Value of a default routing key to use for send operations.
spring.rabbitmq.username=guest # Login user to authenticate to the broker.
spring.rabbitmq.virtual-host= # Virtual host to use when connecting to the broker.

# ---------------------------------------# ACTUATOR PROPERTIES
# ---------------------------------------# MANAGEMENT HTTP SERVER (ManagementServerProperties)
management.server.add-application-context-header=false # Add the "X-Application-Context" HTTP header in each response.
management.server.address= # Network address to which the management endpoints should bind. Requires a custom management.serve
management.server.port= # Management endpoint HTTP port (uses the same port as the application by default). Configure a differ
management.server.servlet.context-path= # Management endpoint context-path (for instance, `/management`). Requires a custom ma
management.server.ssl.ciphers= # Supported SSL ciphers.
management.server.ssl.client-auth= # Client authentication mode.
management.server.ssl.enabled=true # Whether to enable SSL support.
management.server.ssl.enabled-protocols= # Enabled SSL protocols.
management.server.ssl.key-alias= # Alias that identifies the key in the key store.
management.server.ssl.key-password= # Password used to access the key in the key store.
management.server.ssl.key-store= # Path to the key store that holds the SSL certificate (typically a jks file).
management.server.ssl.key-store-password= # Password used to access the key store.
management.server.ssl.key-store-provider= # Provider for the key store.
management.server.ssl.key-store-type= # Type of the key store.
management.server.ssl.protocol=TLS # SSL protocol to use.
management.server.ssl.trust-store= # Trust store that holds SSL certificates.
management.server.ssl.trust-store-password= # Password used to access the trust store.
management.server.ssl.trust-store-provider= # Provider for the trust store.
management.server.ssl.trust-store-type= # Type of the trust store.
# CLOUDFOUNDRY
management.cloudfoundry.enabled=true # Whether to enable extended Cloud Foundry actuator endpoints.
management.cloudfoundry.skip-ssl-validation=false # Whether to skip SSL verification for Cloud Foundry actuator endpoint secur
# ENDPOINTS GENERAL CONFIGURATION
management.endpoints.enabled-by-default= # Whether to enable or disable all endpoints by default.
# ENDPOINTS JMX CONFIGURATION (JmxEndpointProperties)
management.endpoints.jmx.domain=org.springframework.boot # Endpoints JMX domain name. Fallback to 'spring.jmx.default-domain'
management.endpoints.jmx.exposure.include=* # Endpoint IDs that should be included or '*' for all.
management.endpoints.jmx.exposure.exclude= # Endpoint IDs that should be excluded or '*' for all.
management.endpoints.jmx.static-names= # Additional static properties to append to all ObjectNames of MBeans representing Endp
# ENDPOINTS WEB CONFIGURATION (WebEndpointProperties)
management.endpoints.web.exposure.include=health,info # Endpoint IDs that should be included or '*' for all.
management.endpoints.web.exposure.exclude= # Endpoint IDs that should be excluded or '*' for all.
management.endpoints.web.base-path=/actuator # Base path for Web endpoints. Relative to server.servlet.context-path or managem
management.endpoints.web.path-mapping= # Mapping between endpoint IDs and the path that should expose them.
# ENDPOINTS CORS CONFIGURATION (CorsEndpointProperties)
management.endpoints.web.cors.allow-credentials= # Whether credentials are supported. When not set, credentials are not suppor
management.endpoints.web.cors.allowed-headers= # Comma-separated list of headers to allow in a request. '*' allows all headers
management.endpoints.web.cors.allowed-methods= # Comma-separated list of methods to allow. '*' allows all methods. When not se
management.endpoints.web.cors.allowed-origins= # Comma-separated list of origins to allow. '*' allows all origins. When not se
management.endpoints.web.cors.exposed-headers= # Comma-separated list of headers to include in a response.
management.endpoints.web.cors.max-age=1800s # How long the response from a pre-flight request can be cached by clients. If a d
# AUDIT EVENTS ENDPOINT (AuditEventsEndpoint)
management.endpoint.auditevents.cache.time-to-live=0ms # Maximum time that a response can be cached.
management.endpoint.auditevents.enabled=true # Whether to enable the auditevents endpoint.
# BEANS ENDPOINT (BeansEndpoint)
management.endpoint.beans.cache.time-to-live=0ms # Maximum time that a response can be cached.
management.endpoint.beans.enabled=true # Whether to enable the beans endpoint.

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# CACHES ENDPOINT (CachesEndpoint)
management.endpoint.caches.cache.time-to-live=0ms # Maximum time that a response can be cached.
management.endpoint.caches.enabled=true # Whether to enable the caches endpoint.
# CONDITIONS REPORT ENDPOINT (ConditionsReportEndpoint)
management.endpoint.conditions.cache.time-to-live=0ms # Maximum time that a response can be cached.
management.endpoint.conditions.enabled=true # Whether to enable the conditions endpoint.
# CONFIGURATION PROPERTIES REPORT ENDPOINT (ConfigurationPropertiesReportEndpoint, ConfigurationPropertiesReportEndpointProper
management.endpoint.configprops.cache.time-to-live=0ms # Maximum time that a response can be cached.
management.endpoint.configprops.enabled=true # Whether to enable the configprops endpoint.
management.endpoint.configprops.keys-to-sanitize=password,secret,key,token,.*credentials.*,vcap_services,sun.java.command # Ke
# ENVIRONMENT ENDPOINT (EnvironmentEndpoint, EnvironmentEndpointProperties)
management.endpoint.env.cache.time-to-live=0ms # Maximum time that a response can be cached.
management.endpoint.env.enabled=true # Whether to enable the env endpoint.
management.endpoint.env.keys-to-sanitize=password,secret,key,token,.*credentials.*,vcap_services,sun.java.command # Keys that
# FLYWAY ENDPOINT (FlywayEndpoint)
management.endpoint.flyway.cache.time-to-live=0ms # Maximum time that a response can be cached.
management.endpoint.flyway.enabled=true # Whether to enable the flyway endpoint.
# HEALTH ENDPOINT (HealthEndpoint, HealthEndpointProperties)
management.endpoint.health.cache.time-to-live=0ms # Maximum time that a response can be cached.
management.endpoint.health.enabled=true # Whether to enable the health endpoint.
management.endpoint.health.roles= # Roles used to determine whether or not a user is authorized to be shown details. When empt
management.endpoint.health.show-details=never # When to show full health details.
# HEAP DUMP ENDPOINT (HeapDumpWebEndpoint)
management.endpoint.heapdump.cache.time-to-live=0ms # Maximum time that a response can be cached.
management.endpoint.heapdump.enabled=true # Whether to enable the heapdump endpoint.
# HTTP TRACE ENDPOINT (HttpTraceEndpoint)
management.endpoint.httptrace.cache.time-to-live=0ms # Maximum time that a response can be cached.
management.endpoint.httptrace.enabled=true # Whether to enable the httptrace endpoint.
# INFO ENDPOINT (InfoEndpoint)
info= # Arbitrary properties to add to the info endpoint.
management.endpoint.info.cache.time-to-live=0ms # Maximum time that a response can be cached.
management.endpoint.info.enabled=true # Whether to enable the info endpoint.
# INTEGRATION GRAPH ENDPOINT (IntegrationGraphEndpoint)
management.endpoint.integrationgraph.cache.time-to-live=0ms # Maximum time that a response can be cached.
management.endpoint.integrationgraph.enabled=true # Whether to enable the integrationgraph endpoint.
# JOLOKIA ENDPOINT (JolokiaProperties)
management.endpoint.jolokia.config.*= # Jolokia settings. Refer to the documentation of Jolokia for more details.
management.endpoint.jolokia.enabled=true # Whether to enable the jolokia endpoint.
# LIQUIBASE ENDPOINT (LiquibaseEndpoint)
management.endpoint.liquibase.cache.time-to-live=0ms # Maximum time that a response can be cached.
management.endpoint.liquibase.enabled=true # Whether to enable the liquibase endpoint.
# LOG FILE ENDPOINT (LogFileWebEndpoint, LogFileWebEndpointProperties)
management.endpoint.logfile.cache.time-to-live=0ms # Maximum time that a response can be cached.
management.endpoint.logfile.enabled=true # Whether to enable the logfile endpoint.
management.endpoint.logfile.external-file= # External Logfile to be accessed. Can be used if the logfile is written by output
# LOGGERS ENDPOINT (LoggersEndpoint)
management.endpoint.loggers.cache.time-to-live=0ms # Maximum time that a response can be cached.
management.endpoint.loggers.enabled=true # Whether to enable the loggers endpoint.
# REQUEST MAPPING ENDPOINT (MappingsEndpoint)
management.endpoint.mappings.cache.time-to-live=0ms # Maximum time that a response can be cached.
management.endpoint.mappings.enabled=true # Whether to enable the mappings endpoint.
# METRICS ENDPOINT (MetricsEndpoint)
management.endpoint.metrics.cache.time-to-live=0ms # Maximum time that a response can be cached.
management.endpoint.metrics.enabled=true # Whether to enable the metrics endpoint.

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# PROMETHEUS ENDPOINT (PrometheusScrapeEndpoint)
management.endpoint.prometheus.cache.time-to-live=0ms # Maximum time that a response can be cached.
management.endpoint.prometheus.enabled=true # Whether to enable the prometheus endpoint.
# SCHEDULED TASKS ENDPOINT (ScheduledTasksEndpoint)
management.endpoint.scheduledtasks.cache.time-to-live=0ms # Maximum time that a response can be cached.
management.endpoint.scheduledtasks.enabled=true # Whether to enable the scheduledtasks endpoint.
# SESSIONS ENDPOINT (SessionsEndpoint)
management.endpoint.sessions.enabled=true # Whether to enable the sessions endpoint.
# SHUTDOWN ENDPOINT (ShutdownEndpoint)
management.endpoint.shutdown.enabled=false # Whether to enable the shutdown endpoint.
# THREAD DUMP ENDPOINT (ThreadDumpEndpoint)
management.endpoint.threaddump.cache.time-to-live=0ms # Maximum time that a response can be cached.
management.endpoint.threaddump.enabled=true # Whether to enable the threaddump endpoint.
# HEALTH INDICATORS
management.health.db.enabled=true # Whether to enable database health check.
management.health.cassandra.enabled=true # Whether to enable Cassandra health check.
management.health.couchbase.enabled=true # Whether to enable Couchbase health check.
management.health.defaults.enabled=true # Whether to enable default health indicators.
management.health.diskspace.enabled=true # Whether to enable disk space health check.
management.health.diskspace.path= # Path used to compute the available disk space.
management.health.diskspace.threshold=10MB # Minimum disk space that should be available.
management.health.elasticsearch.enabled=true # Whether to enable Elasticsearch health check.
management.health.elasticsearch.indices= # Comma-separated index names.
management.health.elasticsearch.response-timeout=100ms # Time to wait for a response from the cluster.
management.health.influxdb.enabled=true # Whether to enable InfluxDB health check.
management.health.jms.enabled=true # Whether to enable JMS health check.
management.health.ldap.enabled=true # Whether to enable LDAP health check.
management.health.mail.enabled=true # Whether to enable Mail health check.
management.health.mongo.enabled=true # Whether to enable MongoDB health check.
management.health.neo4j.enabled=true # Whether to enable Neo4j health check.
management.health.rabbit.enabled=true # Whether to enable RabbitMQ health check.
management.health.redis.enabled=true # Whether to enable Redis health check.
management.health.solr.enabled=true # Whether to enable Solr health check.
management.health.status.http-mapping= # Mapping of health statuses to HTTP status codes. By default, registered health status
management.health.status.order=DOWN,OUT_OF_SERVICE,UP,UNKNOWN # Comma-separated list of health statuses in order of severity.
# HTTP TRACING (HttpTraceProperties)
management.trace.http.enabled=true # Whether to enable HTTP request-response tracing.
management.trace.http.include=request-headers,response-headers,cookies,errors # Items to be included in the trace.
# INFO CONTRIBUTORS (InfoContributorProperties)
management.info.build.enabled=true # Whether to enable build info.
management.info.defaults.enabled=true # Whether to enable default info contributors.
management.info.env.enabled=true # Whether to enable environment info.
management.info.git.enabled=true # Whether to enable git info.
management.info.git.mode=simple # Mode to use to expose git information.
# METRICS
management.metrics.distribution.maximum-expected-value.*= # Maximum value that meter IDs starting-with the specified name are
management.metrics.distribution.minimum-expected-value.*= # Minimum value that meter IDs starting-with the specified name are
management.metrics.distribution.percentiles.*= # Specific computed non-aggregable percentiles to ship to the backend for meter
management.metrics.distribution.percentiles-histogram.*= # Whether meter IDs starting with the specified name should publish p
management.metrics.distribution.sla.*= # Specific SLA boundaries for meter IDs starting-with the specified name. The longest m
management.metrics.enable.*= # Whether meter IDs starting-with the specified name should be enabled. The longest match wins, t
management.metrics.export.appoptics.api-token= # AppOptics API token.
management.metrics.export.appoptics.batch-size=500 # Number of measurements per request to use for this backend. If more measu
management.metrics.export.appoptics.connect-timeout=5s # Connection timeout for requests to this backend.
management.metrics.export.appoptics.enabled=true # Whether exporting of metrics to this backend is enabled.
management.metrics.export.appoptics.host-tag=instance # Tag that will be mapped to "@host" when shipping metrics to AppOptics.
management.metrics.export.appoptics.num-threads=2 # Number of threads to use with the metrics publishing scheduler.
management.metrics.export.appoptics.read-timeout=10s # Read timeout for requests to this backend.
management.metrics.export.appoptics.step=1m # Step size (i.e. reporting frequency) to use.
management.metrics.export.appoptics.uri=https://api.appoptics.com/v1/measurements # URI to ship metrics to.
management.metrics.export.atlas.batch-size=10000 # Number of measurements per request to use for this backend. If more measure

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management.metrics.export.atlas.config-refresh-frequency=10s # Frequency for refreshing config settings from the LWC service.
management.metrics.export.atlas.config-time-to-live=150s # Time to live for subscriptions from the LWC service.
management.metrics.export.atlas.config-uri=http://localhost:7101/lwc/api/v1/expressions/local-dev # URI for the Atlas LWC endp
management.metrics.export.atlas.connect-timeout=1s # Connection timeout for requests to this backend.
management.metrics.export.atlas.enabled=true # Whether exporting of metrics to this backend is enabled.
management.metrics.export.atlas.eval-uri=http://localhost:7101/lwc/api/v1/evaluate # URI for the Atlas LWC endpoint to evaluat
management.metrics.export.atlas.lwc-enabled=false # Whether to enable streaming to Atlas LWC.
management.metrics.export.atlas.meter-time-to-live=15m # Time to live for meters that do not have any activity. After this per
management.metrics.export.atlas.num-threads=2 # Number of threads to use with the metrics publishing scheduler.
management.metrics.export.atlas.read-timeout=10s # Read timeout for requests to this backend.
management.metrics.export.atlas.step=1m # Step size (i.e. reporting frequency) to use.
management.metrics.export.atlas.uri=http://localhost:7101/api/v1/publish # URI of the Atlas server.
management.metrics.export.datadog.api-key= # Datadog API key.
management.metrics.export.datadog.application-key= # Datadog application key. Not strictly required, but improves the Datadog
management.metrics.export.datadog.batch-size=10000 # Number of measurements per request to use for this backend. If more measu
management.metrics.export.datadog.connect-timeout=1s # Connection timeout for requests to this backend.
management.metrics.export.datadog.descriptions=true # Whether to publish descriptions metadata to Datadog. Turn this off to mi
management.metrics.export.datadog.enabled=true # Whether exporting of metrics to this backend is enabled.
management.metrics.export.datadog.host-tag=instance # Tag that will be mapped to "host" when shipping metrics to Datadog.
management.metrics.export.datadog.num-threads=2 # Number of threads to use with the metrics publishing scheduler.
management.metrics.export.datadog.read-timeout=10s # Read timeout for requests to this backend.
management.metrics.export.datadog.step=1m # Step size (i.e. reporting frequency) to use.
management.metrics.export.datadog.uri=https://app.datadoghq.com # URI to ship metrics to. If you need to publish metrics to an
management.metrics.export.dynatrace.api-token= # Dynatrace authentication token.
management.metrics.export.dynatrace.batch-size=10000 # Number of measurements per request to use for this backend. If more mea
management.metrics.export.dynatrace.connect-timeout=1s # Connection timeout for requests to this backend.
management.metrics.export.dynatrace.device-id= # ID of the custom device that is exporting metrics to Dynatrace.
management.metrics.export.dynatrace.enabled=true # Whether exporting of metrics to this backend is enabled.
management.metrics.export.dynatrace.num-threads=2 # Number of threads to use with the metrics publishing scheduler.
management.metrics.export.dynatrace.read-timeout=10s # Read timeout for requests to this backend.
management.metrics.export.dynatrace.step=1m # Step size (i.e. reporting frequency) to use.
management.metrics.export.dynatrace.technology-type=java # Technology type for exported metrics. Used to group metrics under a
management.metrics.export.dynatrace.uri= # URI to ship metrics to. Should be used for SaaS, self managed instances or to en-ro
management.metrics.export.elastic.auto-create-index=true # Whether to create the index automatically if it does not exist.
management.metrics.export.elastic.batch-size=10000 # Number of measurements per request to use for this backend. If more measu
management.metrics.export.elastic.connect-timeout=1s # Connection timeout for requests to this backend.
management.metrics.export.elastic.enabled=true # Whether exporting of metrics to this backend is enabled.
management.metrics.export.elastic.host=http://localhost:9200 # Host to export metrics to.
management.metrics.export.elastic.index=metrics # Index to export metrics to.
management.metrics.export.elastic.index-date-format=yyyy-MM # Index date format used for rolling indices. Appended to the inde
management.metrics.export.elastic.num-threads=2 # Number of threads to use with the metrics publishing scheduler.
management.metrics.export.elastic.password= # Login password of the Elastic server.
management.metrics.export.elastic.read-timeout=10s # Read timeout for requests to this backend.
management.metrics.export.elastic.step=1m # Step size (i.e. reporting frequency) to use.
management.metrics.export.elastic.timestamp-field-name=@timestamp # Name of the timestamp field.
management.metrics.export.elastic.user-name= # Login user of the Elastic server.
management.metrics.export.ganglia.addressing-mode=multicast # UDP addressing mode, either unicast or multicast.
management.metrics.export.ganglia.duration-units=milliseconds # Base time unit used to report durations.
management.metrics.export.ganglia.enabled=true # Whether exporting of metrics to Ganglia is enabled.
management.metrics.export.ganglia.host=localhost # Host of the Ganglia server to receive exported metrics.
management.metrics.export.ganglia.port=8649 # Port of the Ganglia server to receive exported metrics.
management.metrics.export.ganglia.protocol-version=3.1 # Ganglia protocol version. Must be either 3.1 or 3.0.
management.metrics.export.ganglia.rate-units=seconds # Base time unit used to report rates.
management.metrics.export.ganglia.step=1m # Step size (i.e. reporting frequency) to use.
management.metrics.export.ganglia.time-to-live=1 # Time to live for metrics on Ganglia. Set the multi-cast Time-To-Live to be
management.metrics.export.graphite.duration-units=milliseconds # Base time unit used to report durations.
management.metrics.export.graphite.enabled=true # Whether exporting of metrics to Graphite is enabled.
management.metrics.export.graphite.host=localhost # Host of the Graphite server to receive exported metrics.
management.metrics.export.graphite.port=2004 # Port of the Graphite server to receive exported metrics.
management.metrics.export.graphite.protocol=pickled # Protocol to use while shipping data to Graphite.
management.metrics.export.graphite.rate-units=seconds # Base time unit used to report rates.
management.metrics.export.graphite.step=1m # Step size (i.e. reporting frequency) to use.
management.metrics.export.graphite.tags-as-prefix= # For the default naming convention, turn the specified tag keys into part
management.metrics.export.humio.api-token= # Humio API token.
management.metrics.export.humio.batch-size=10000 # Number of measurements per request to use for this backend. If more measure
management.metrics.export.humio.connect-timeout=5s # Connection timeout for requests to this backend.
management.metrics.export.humio.enabled=true # Whether exporting of metrics to this backend is enabled.
management.metrics.export.humio.num-threads=2 # Number of threads to use with the metrics publishing scheduler.
management.metrics.export.humio.read-timeout=10s # Read timeout for requests to this backend.
management.metrics.export.humio.repository=sandbox # Name of the repository to publish metrics to.

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management.metrics.export.humio.step=1m # Step size (i.e. reporting frequency) to use.
management.metrics.export.humio.tags.*= # Humio tags describing the data source in which metrics will be stored. Humio tags ar
management.metrics.export.humio.uri=https://cloud.humio.com # URI to ship metrics to. If you need to publish metrics to an int
management.metrics.export.influx.auto-create-db=true # Whether to create the Influx database if it does not exist before attem
management.metrics.export.influx.batch-size=10000 # Number of measurements per request to use for this backend. If more measur
management.metrics.export.influx.compressed=true # Whether to enable GZIP compression of metrics batches published to Influx.
management.metrics.export.influx.connect-timeout=1s # Connection timeout for requests to this backend.
management.metrics.export.influx.consistency=one # Write consistency for each point.
management.metrics.export.influx.db=mydb # Tag that will be mapped to "host" when shipping metrics to Influx.
management.metrics.export.influx.enabled=true # Whether exporting of metrics to this backend is enabled.
management.metrics.export.influx.num-threads=2 # Number of threads to use with the metrics publishing scheduler.
management.metrics.export.influx.password= # Login password of the Influx server.
management.metrics.export.influx.read-timeout=10s # Read timeout for requests to this backend.
management.metrics.export.influx.retention-duration= # Time period for which Influx should retain data in the current database
management.metrics.export.influx.retention-shard-duration= # Time range covered by a shard group.
management.metrics.export.influx.retention-policy= # Retention policy to use (Influx writes to the DEFAULT retention policy if
management.metrics.export.influx.retention-replication-factor= # How many copies of the data are stored in the cluster.
management.metrics.export.influx.step=1m # Step size (i.e. reporting frequency) to use.
management.metrics.export.influx.uri=http://localhost:8086 # URI of the Influx server.
management.metrics.export.influx.user-name= # Login user of the Influx server.
management.metrics.export.jmx.domain=metrics # Metrics JMX domain name.
management.metrics.export.jmx.enabled=true # Whether exporting of metrics to JMX is enabled.
management.metrics.export.jmx.step=1m # Step size (i.e. reporting frequency) to use.
management.metrics.export.kairos.batch-size=10000 # Number of measurements per request to use for this backend. If more measur
management.metrics.export.kairos.connect-timeout=1s # Connection timeout for requests to this backend.
management.metrics.export.kairos.enabled=true # Whether exporting of metrics to this backend is enabled.
management.metrics.export.kairos.num-threads=2 # Number of threads to use with the metrics publishing scheduler.
management.metrics.export.kairos.password= # Login password of the KairosDB server.
management.metrics.export.kairos.read-timeout=10s # Read timeout for requests to this backend.
management.metrics.export.kairos.step=1m # Step size (i.e. reporting frequency) to use.
management.metrics.export.kairos.uri= localhost:8080/api/v1/datapoints # URI of the KairosDB server.
management.metrics.export.kairos.user-name= # Login user of the KairosDB server.
management.metrics.export.newrelic.account-id= # New Relic account ID.
management.metrics.export.newrelic.api-key= # New Relic API key.
management.metrics.export.newrelic.batch-size=10000 # Number of measurements per request to use for this backend. If more meas
management.metrics.export.newrelic.connect-timeout=1s # Connection timeout for requests to this backend.
management.metrics.export.newrelic.enabled=true # Whether exporting of metrics to this backend is enabled.
management.metrics.export.newrelic.num-threads=2 # Number of threads to use with the metrics publishing scheduler.
management.metrics.export.newrelic.read-timeout=10s # Read timeout for requests to this backend.
management.metrics.export.newrelic.step=1m # Step size (i.e. reporting frequency) to use.
management.metrics.export.newrelic.uri=https://insights-collector.newrelic.com # URI to ship metrics to.
management.metrics.export.prometheus.descriptions=true # Whether to enable publishing descriptions as part of the scrape paylo
management.metrics.export.prometheus.enabled=true # Whether exporting of metrics to Prometheus is enabled.
management.metrics.export.prometheus.step=1m # Step size (i.e. reporting frequency) to use.
management.metrics.export.prometheus.pushgateway.base-url=localhost:9091 # Base URL for the Pushgateway.
management.metrics.export.prometheus.pushgateway.enabled=false # Enable publishing via a Prometheus Pushgateway.
management.metrics.export.prometheus.pushgateway.grouping-key= # Grouping key for the pushed metrics.
management.metrics.export.prometheus.pushgateway.job= # Job identifier for this application instance.
management.metrics.export.prometheus.pushgateway.push-rate=1m # Frequency with which to push metrics.
management.metrics.export.prometheus.pushgateway.shutdown-operation= # Operation that should be performed on shutdown.
management.metrics.export.signalfx.access-token= # SignalFX access token.
management.metrics.export.signalfx.batch-size=10000 # Number of measurements per request to use for this backend. If more meas
management.metrics.export.signalfx.connect-timeout=1s # Connection timeout for requests to this backend.
management.metrics.export.signalfx.enabled=true # Whether exporting of metrics to this backend is enabled.
management.metrics.export.signalfx.num-threads=2 # Number of threads to use with the metrics publishing scheduler.
management.metrics.export.signalfx.read-timeout=10s # Read timeout for requests to this backend.
management.metrics.export.signalfx.source= # Uniquely identifies the app instance that is publishing metrics to SignalFx. Defa
management.metrics.export.signalfx.step=10s # Step size (i.e. reporting frequency) to use.
management.metrics.export.signalfx.uri=https://ingest.signalfx.com # URI to ship metrics to.
management.metrics.export.simple.enabled=true # Whether, in the absence of any other exporter, exporting of metrics to an in-m
management.metrics.export.simple.mode=cumulative # Counting mode.
management.metrics.export.simple.step=1m # Step size (i.e. reporting frequency) to use.
management.metrics.export.statsd.enabled=true # Whether exporting of metrics to StatsD is enabled.
management.metrics.export.statsd.flavor=datadog # StatsD line protocol to use.
management.metrics.export.statsd.host=localhost # Host of the StatsD server to receive exported metrics.
management.metrics.export.statsd.max-packet-length=1400 # Total length of a single payload should be kept within your network'
management.metrics.export.statsd.polling-frequency=10s # How often gauges will be polled. When a gauge is polled, its value is
management.metrics.export.statsd.port=8125 # Port of the StatsD server to receive exported metrics.
management.metrics.export.statsd.publish-unchanged-meters=true # Whether to send unchanged meters to the StatsD server.
management.metrics.export.wavefront.api-token= # API token used when publishing metrics directly to the Wavefront API host.

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management.metrics.export.wavefront.batch-size=10000 # Number of measurements per request to use for this backend. If more mea
management.metrics.export.wavefront.connect-timeout=1s # Connection timeout for requests to this backend.
management.metrics.export.wavefront.enabled=true # Whether exporting of metrics to this backend is enabled.
management.metrics.export.wavefront.global-prefix= # Global prefix to separate metrics originating from this app's white box i
management.metrics.export.wavefront.num-threads=2 # Number of threads to use with the metrics publishing scheduler.
management.metrics.export.wavefront.read-timeout=10s # Read timeout for requests to this backend.
management.metrics.export.wavefront.source= # Unique identifier for the app instance that is the source of metrics being publi
management.metrics.export.wavefront.step=10s # Step size (i.e. reporting frequency) to use.
management.metrics.export.wavefront.uri=https://longboard.wavefront.com # URI to ship metrics to.
management.metrics.use-global-registry=true # Whether auto-configured MeterRegistry implementations should be bound to the glo
management.metrics.tags.*= # Common tags that are applied to every meter.
management.metrics.web.client.max-uri-tags=100 # Maximum number of unique URI tag values allowed. After the max number of tag
management.metrics.web.client.requests-metric-name=http.client.requests # Name of the metric for sent requests.
management.metrics.web.server.auto-time-requests=true # Whether requests handled by Spring MVC, WebFlux or Jersey should be au
management.metrics.web.server.max-uri-tags=100 # Maximum number of unique URI tag values allowed. After the max number of tag
management.metrics.web.server.requests-metric-name=http.server.requests # Name of the metric for received requests.

# ---------------------------------------# DEVTOOLS PROPERTIES
# ---------------------------------------# DEVTOOLS (DevToolsProperties)
spring.devtools.add-properties=true # Whether to enable development property defaults.
spring.devtools.livereload.enabled=true # Whether to enable a livereload.com-compatible server.
spring.devtools.livereload.port=35729 # Server port.
spring.devtools.restart.additional-exclude= # Additional patterns that should be excluded from triggering a full restart.
spring.devtools.restart.additional-paths= # Additional paths to watch for changes.
spring.devtools.restart.enabled=true # Whether to enable automatic restart.
spring.devtools.restart.exclude=META-INF/maven/**,META-INF/resources/**,resources/**,static/**,public/**,templates/**,**/*Test
spring.devtools.restart.log-condition-evaluation-delta=true # Whether to log the condition evaluation delta upon restart.
spring.devtools.restart.poll-interval=1s # Amount of time to wait between polling for classpath changes.
spring.devtools.restart.quiet-period=400ms # Amount of quiet time required without any classpath changes before a restart is t
spring.devtools.restart.trigger-file= # Name of a specific file that, when changed, triggers the restart check. If not specifi
# REMOTE DEVTOOLS (RemoteDevToolsProperties)
spring.devtools.remote.context-path=/.~~spring-boot!~ # Context path used to handle the remote connection.
spring.devtools.remote.proxy.host= # The host of the proxy to use to connect to the remote application.
spring.devtools.remote.proxy.port= # The port of the proxy to use to connect to the remote application.
spring.devtools.remote.restart.enabled=true # Whether to enable remote restart.
spring.devtools.remote.secret= # A shared secret required to establish a connection (required to enable remote support).
spring.devtools.remote.secret-header-name=X-AUTH-TOKEN # HTTP header used to transfer the shared secret.

# ---------------------------------------# TESTING PROPERTIES
# ---------------------------------------spring.test.database.replace=any # Type of existing DataSource to replace.
spring.test.mockmvc.print=default # MVC Print option.

Appendix B. Configuration Metadata
Spring Boot jars include metadata files that provide details of all supported configuration properties. The files are designed to let IDE developers
offer contextual help and “code completion” as users are working with application.properties or application.yml files.
The majority of the metadata file is generated automatically at compile time by processing all items annotated with @ConfigurationProperties .
However, it is possible to write part of the metadata manually for corner cases or more advanced use cases.

B.1 Metadata Format
Configuration metadata files are located inside jars under META-INF/spring-configuration-metadata.json They use a simple JSON format
with items categorized under either “groups” or “properties” and additional values hints categorized under "hints", as shown in the following example:
{"groups": [
{

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{

"name": "server",
"type": "org.springframework.boot.autoconfigure.web.ServerProperties",
"sourceType": "org.springframework.boot.autoconfigure.web.ServerProperties"
},
{
"name": "spring.jpa.hibernate",
"type": "org.springframework.boot.autoconfigure.orm.jpa.JpaProperties$Hibernate",
"sourceType": "org.springframework.boot.autoconfigure.orm.jpa.JpaProperties",
"sourceMethod": "getHibernate()"
}
...
],"properties": [
{
"name": "server.port",
"type": "java.lang.Integer",
"sourceType": "org.springframework.boot.autoconfigure.web.ServerProperties"
},
{
"name": "server.address",
"type": "java.net.InetAddress",
"sourceType": "org.springframework.boot.autoconfigure.web.ServerProperties"
},
{
"name": "spring.jpa.hibernate.ddl-auto",
"type": "java.lang.String",
"description": "DDL mode. This is actually a shortcut for the \"hibernate.hbm2ddl.auto\" property.",
"sourceType": "org.springframework.boot.autoconfigure.orm.jpa.JpaProperties$Hibernate"
}
...
],"hints": [
{
"name": "spring.jpa.hibernate.ddl-auto",
"values": [
{
"value": "none",
"description": "Disable DDL handling."
},
{
"value": "validate",
"description": "Validate the schema, make no changes to the database."
},
{
"value": "update",
"description": "Update the schema if necessary."
},
{
"value": "create",
"description": "Create the schema and destroy previous data."
},
{
"value": "create-drop",
"description": "Create and then destroy the schema at the end of the session."
}
]
}
]}

Each “property” is a configuration item that the user specifies with a given value. For example, server.port and server.address might be
specified in application.properties , as follows:
server.port=9090
server.address=127.0.0.1

The “groups” are higher level items that do not themselves specify a value but instead provide a contextual grouping for properties. For example, the
server.port and server.address properties are part of the server group.

It is not required that every “property” has a “group”. Some properties might exist in their own right.
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Finally, “hints” are additional information used to assist the user in configuring a given property. For example, when a developer is configuring the
spring.jpa.hibernate.ddl-auto property, a tool can use the hints to offer some auto-completion help for the none , validate , update ,
create , and create-drop values.

B.1.1 Group Attributes
The JSON object contained in the groups array can contain the attributes shown in the following table:
Name

Type

Purpose

name

String

The full name of the group. This attribute is mandatory.

type

String

The class name of the data type of the group. For example, if the group were based on a class annotated with
@ConfigurationProperties , the attribute would contain the fully qualified name of that class. If it were based on
a @Bean method, it would be the return type of that method. If the type is not known, the attribute may be omitted.

description

String

A short description of the group that can be displayed to users. If not description is available, it may be omitted. It is
recommended that descriptions be short paragraphs, with the first line providing a concise summary. The last line
in the description should end with a period ( . ).

sourceType

String

The class name of the source that contributed this group. For example, if the group were based on a @Bean
method annotated with @ConfigurationProperties , this attribute would contain the fully qualified name of the
@Configuration class that contains the method. If the source type is not known, the attribute may be omitted.

sourceMethod

String

The full name of the method (include parenthesis and argument types) that contributed this group (for example, the
name of a @ConfigurationProperties annotated @Bean method). If the source method is not known, it may be
omitted.

B.1.2 Property Attributes
The JSON object contained in the properties array can contain the attributes described in the following table:
Name

Type

Purpose

name

String

The full name of the property. Names are in lower-case period-separated form (for example,
server.address ). This attribute is mandatory.

type

String

The full signature of the data type of the property (for example, java.lang.String ) but also a full generic
type (such as java.util.Map ). You can use this attribute to guide the
user as to the types of values that they can enter. For consistency, the type of a primitive is specified by
using its wrapper counterpart (for example, boolean becomes java.lang.Boolean ). Note that this class
may be a complex type that gets converted from a String as values are bound. If the type is not known, it
may be omitted.

description

String

A short description of the group that can be displayed to users. If no description is available, it may be
omitted. It is recommended that descriptions be short paragraphs, with the first line providing a concise
summary. The last line in the description should end with a period ( . ).

sourceType

String

The class name of the source that contributed this property. For example, if the property were from a class
annotated with @ConfigurationProperties , this attribute would contain the fully qualified name of that
class. If the source type is unknown, it may be omitted.

defaultValue

Object

The default value, which is used if the property is not specified. If the type of the property is an array, it can
be an array of value(s). If the default value is unknown, it may be omitted.

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Name

Type

Purpose

deprecation

Deprecation

Specify whether the property is deprecated. If the field is not deprecated or if that information is not known, it
may be omitted. The next table offers more detail about the deprecation attribute.

The JSON object contained in the deprecation attribute of each properties element can contain the following attributes:
Name

Type

Purpose

level

String

The level of deprecation, which can be either warning (the default) or error . When a property has a warning
deprecation level, it should still be bound in the environment. However, when it has an error deprecation level, the
property is no longer managed and is not bound.

reason

String

A short description of the reason why the property was deprecated. If no reason is available, it may be omitted. It is
recommended that descriptions be short paragraphs, with the first line providing a concise summary. The last line in
the description should end with a period ( . ).

replacement

String

The full name of the property that replaces this deprecated property. If there is no replacement for this property, it
may be omitted.

Prior to Spring Boot 1.3, a single deprecated boolean attribute can be used instead of the deprecation element. This is still
supported in a deprecated fashion and should no longer be used. If no reason and replacement are available, an empty
deprecation object should be set.

Deprecation can also be specified declaratively in code by adding the @DeprecatedConfigurationProperty annotation to the getter exposing the
deprecated property. For instance, assume that the app.acme.target property was confusing and was renamed to app.acme.name . The
following example shows how to handle that situation:
@ConfigurationProperties("app.acme")
public class AcmeProperties {
private String name;
public String getName() { ... }
public void setName(String name) { ... }
@DeprecatedConfigurationProperty(replacement = "app.acme.name")
@Deprecated
public String getTarget() {
return getName();
}
@Deprecated
public void setTarget(String target) {
setName(target);
}
}

There is no way to set a level . warning is always assumed, since code is still handling the property.

The preceding code makes sure that the deprecated property still works (delegating to the name property behind the scenes). Once the
getTarget and setTarget methods can be removed from your public API, the automatic deprecation hint in the metadata goes away as well. If
you want to keep a hint, adding manual metadata with an error deprecation level ensures that users are still informed about that property. Doing
so is particularly useful when a replacement is provided.

B.1.3 Hint Attributes
The JSON object contained in the hints array can contain the attributes shown in the following table:
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Name

Type

Purpose

name

String

The full name of the property to which this hint refers. Names are in lower-case period-separated form (such
as spring.mvc.servlet.path ). If the property refers to a map (such as system.contexts ), the hint
either applies to the keys of the map ( system.context.keys ) or the values ( system.context.values ) of
the map. This attribute is mandatory.

values

A list of valid values as defined by the ValueHint object (described in the next table). Each entry defines

ValueHint[]

the value and may have a description.
providers

ValueProvider[]

A list of providers as defined by the ValueProvider object (described later in this document). Each entry
defines the name of the provider and its parameters, if any.

The JSON object contained in the values attribute of each hint element can contain the attributes described in the following table:
Name

Type

Purpose

value

Object

A valid value for the element to which the hint refers. If the type of the property is an array, it can also be an array of
value(s). This attribute is mandatory.

description

String

A short description of the value that can be displayed to users. If no description is available, it may be omitted . It is
recommended that descriptions be short paragraphs, with the first line providing a concise summary. The last line in
the description should end with a period ( . ).

The JSON object contained in the providers attribute of each hint element can contain the attributes described in the following table:
Name

Type

Purpose

name

String

The name of the provider to use to offer additional content assistance for the element to which the hint refers.

parameters

JSON object

Any additional parameter that the provider supports (check the documentation of the provider for more details).

B.1.4 Repeated Metadata Items
Objects with the same “property” and “group” name can appear multiple times within a metadata file. For example, you could bind two separate
classes to the same prefix, with each having potentially overlapping property names. While the same names appearing in the metadata multiple
times should not be common, consumers of metadata should take care to ensure that they support it.

B.2 Providing Manual Hints
To improve the user experience and further assist the user in configuring a given property, you can provide additional metadata that:
Describes the list of potential values for a property.
Associates a provider, to attach a well defined semantic to a property, so that a tool can discover the list of potential values based on the
project’s context.

B.2.1 Value Hint
The name attribute of each hint refers to the name of a property. In the initial example shown earlier, we provide five values for the
spring.jpa.hibernate.ddl-auto property: none , validate , update , create , and create-drop . Each value may have a description as
well.
If your property is of type Map , you can provide hints for both the keys and the values (but not for the map itself). The special .keys and .values
suffixes must refer to the keys and the values, respectively.
Assume a sample.contexts maps magic String values to an integer, as shown in the following example:

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@ConfigurationProperties("sample")
public class SampleProperties {
private Map contexts;
// getters and setters
}

The magic values are (in this example) are sample1 and sample2 . In order to offer additional content assistance for the keys, you could add the
following JSON to the manual metadata of the module:
{"hints": [
{
"name": "sample.contexts.keys",
"values": [
{
"value": "sample1"
},
{
"value": "sample2"
}
]
}
]}

We recommend that you use an Enum for those two values instead. If your IDE supports it, this is by far the most effective approach
to auto-completion.

B.2.2 Value Providers
Providers are a powerful way to attach semantics to a property. In this section, we define the official providers that you can use for your own hints.
However, your favorite IDE may implement some of these or none of them. Also, it could eventually provide its own.

As this is a new feature, IDE vendors must catch up with how it works. Adoption times naturally vary.

The following table summarizes the list of supported providers:
Name

Description

any

Permits any additional value to be provided.

class-reference

Auto-completes the classes available in the project. Usually constrained by a base class that is specified by the
target parameter.

handle-as

Handles the property as if it were defined by the type defined by the mandatory target parameter.

logger-name

Auto-completes valid logger names and logger groups. Typically, package and class names available in the
current project can be auto-completed as well as defined groups.

spring-bean-reference

Auto-completes the available bean names in the current project. Usually constrained by a base class that is
specified by the target parameter.

spring-profile-name

Auto-completes the available Spring profile names in the project.

Only one provider can be active for a given property, but you can specify several providers if they can all manage the property in some
way. Make sure to place the most powerful provider first, as the IDE must use the first one in the JSON section that it can handle. If no
provider for a given property is supported, no special content assistance is provided, either.

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Any
The special any provider value permits any additional values to be provided. Regular value validation based on the property type should be applied
if this is supported.
This provider is typically used if you have a list of values and any extra values should still be considered as valid.
The following example offers on and off as auto-completion values for system.state :
{"hints": [
{
"name": "system.state",
"values": [
{
"value": "on"
},
{
"value": "off"
}
],
"providers": [
{
"name": "any"
}
]
}
]}

Note that, in the preceding example, any other value is also allowed.

Class Reference
The class-reference provider auto-completes classes available in the project. This provider supports the following parameters:
Parameter

Type

Default

Description

value
target

String

none

( Class )

The fully qualified name of the class that should be assignable to the chosen value. Typically used to
filter out-non candidate classes. Note that this information can be provided by the type itself by exposing
a class with the appropriate upper bound.

concrete

boolean

true

Specify whether only concrete classes are to be considered as valid candidates.

The following metadata snippet corresponds to the standard server.servlet.jsp.class-name property that defines the JspServlet class
name to use:
{"hints": [
{
"name": "server.servlet.jsp.class-name",
"providers": [
{
"name": "class-reference",
"parameters": {
"target": "javax.servlet.http.HttpServlet"
}
}
]
}
]}

Handle As
The handle-as provider lets you substitute the type of the property to a more high-level type. This typically happens when the property has a
java.lang.String type, because you do not want your configuration classes to rely on classes that may not be on the classpath. This provider
supports the following parameters:
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Parameter

Type

Default

Description

value
target

String

none

The fully qualified name of the type to consider for the property. This parameter is

( Class )

mandatory.

The following types can be used:
Any java.lang.Enum : Lists the possible values for the property. (We recommend defining the property with the Enum type, as no further hint
should be required for the IDE to auto-complete the values.)
java.nio.charset.Charset : Supports auto-completion of charset/encoding values (such as UTF-8 )
java.util.Locale : auto-completion of locales (such as en_US )
org.springframework.util.MimeType : Supports auto-completion of content type values (such as text/plain )
org.springframework.core.io.Resource : Supports auto-completion of Spring’s Resource abstraction to refer to a file on the filesystem or
on the classpath. (such as classpath:/sample.properties )

If multiple values can be provided, use a Collection or Array type to teach the IDE about it.

The following metadata snippet corresponds to the standard spring.liquibase.change-log property that defines the path to the changelog to
use. It is actually used internally as a org.springframework.core.io.Resource but cannot be exposed as such, because we need to keep the
original String value to pass it to the Liquibase API.
{"hints": [
{
"name": "spring.liquibase.change-log",
"providers": [
{
"name": "handle-as",
"parameters": {
"target": "org.springframework.core.io.Resource"
}
}
]
}
]}

Logger Name
The logger-name provider auto-completes valid logger names and logger groups. Typically, package and class names available in the current
project can be auto-completed. If groups are enabled (default) and if a custom logger group is identified in the configuration, auto-completion for it
should be provided. Specific frameworks may have extra magic logger names that can be supported as well.
This provider supports the following parameters:
Parameter

Type

Default value

Description

group

boolean

true

Specify whether known groups should be considered.

Since a logger name can be any arbitrary name, this provider should allow any value but could highlight valid package and class names that are not
available in the project’s classpath.
The following metadata snippet corresponds to the standard logging.level property. Keys are logger names, and values correspond to the
standard log levels or any custom level. As Spring Boot defines a few logger groups out-of-the-box, dedicated value hints have been added for
those.
{"hints": [
{
"name": "logging.level.keys",
"values": [
{
"value": "root",
"description": "Root logger used to assign the default logging level."
}

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},
{
"value": "sql",
"description": "SQL logging group including Hibernate SQL logger."
},
{
"value": "web",
"description": "Web logging group including codecs."
}
],
"providers": [
{
"name": "logger-name"
}
]
},
{
"name": "logging.level.values",
"values": [
{
"value": "trace"
},
{
"value": "debug"
},
{
"value": "info"
},
{
"value": "warn"
},
{
"value": "error"
},
{
"value": "fatal"
},
{
"value": "off"
}
],
"providers": [
{
"name": "any"
}
]
}

]}

Spring Bean Reference
The spring-bean-reference provider auto-completes the beans that are defined in the configuration of the current project. This provider supports
the following parameters:
Parameter

Type

Default

Description

value
target

String
( Class )

none

The fully qualified name of the bean class that should be assignable to the candidate. Typically
used to filter out non-candidate beans.

The following metadata snippet corresponds to the standard spring.jmx.server property that defines the name of the MBeanServer bean to
use:
{"hints": [
{
"name": "spring.jmx.server",
"providers": [

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[
{

"name": "spring-bean-reference",
"parameters": {
"target": "javax.management.MBeanServer"
}
}
]
}
]}

The binder is not aware of the metadata. If you provide that hint, you still need to transform the bean name into an actual Bean
reference using by the ApplicationContext .

Spring Profile Name
The spring-profile-name provider auto-completes the Spring profiles that are defined in the configuration of the current project.
The following metadata snippet corresponds to the standard spring.profiles.active property that defines the name of the Spring profile(s) to
enable:
{"hints": [
{
"name": "spring.profiles.active",
"providers": [
{
"name": "spring-profile-name"
}
]
}
]}

B.3 Generating Your Own Metadata by Using the Annotation Processor
You can easily generate your own configuration metadata file from items annotated with @ConfigurationProperties by using the
spring-boot-configuration-processor jar. The jar includes a Java annotation processor which is invoked as your project is compiled. To use
the processor, include a dependency on spring-boot-configuration-processor .
With Maven the dependency should be declared as optional, as shown in the following example:

org.springframework.boot
spring-boot-configuration-processor
true


With Gradle 4.5 and earlier, the dependency should be declared in the compileOnly configuration, as shown in the following example:

dependencies {
compileOnly "org.springframework.boot:spring-boot-configuration-processor"
}

With Gradle 4.6 and later, the dependency should be declared in the annotationProcessor configuration, as shown in the following example:
dependencies {
annotationProcessor "org.springframework.boot:spring-boot-configuration-processor"
}

If you are using an additional-spring-configuration-metadata.json file, the compileJava task should be configured to depend on the
processResources task, as shown in the following example:
compileJava.dependsOn(processResources)

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This dependency ensures that the additional metadata is available when the annotation processor runs during compilation.
The processor picks up both classes and methods that are annotated with @ConfigurationProperties . The Javadoc for field values within
configuration classes is used to populate the description attribute.

You should only use simple text with @ConfigurationProperties field Javadoc, since they are not processed before being added to
the JSON.

Properties are discovered through the presence of standard getters and setters with special handling for collection types (that is detected even if
only a getter is present). The annotation processor also supports the use of the @Data , @Getter , and @Setter lombok annotations.

If you are using AspectJ in your project, you need to make sure that the annotation processor runs only once. There are several ways
to do this. With Maven, you can configure the maven-apt-plugin explicitly and add the dependency to the annotation processor only
there. You could also let the AspectJ plugin run all the processing and disable annotation processing in the maven-compiler-plugin
configuration, as follows:

org.apache.maven.plugins
maven-compiler-plugin

none



B.3.1 Nested Properties
The annotation processor automatically considers inner classes as nested properties. Consider the following class:
@ConfigurationProperties(prefix="server")
public class ServerProperties {
private String name;
private Host host;
// ... getter and setters
public static class Host {
private String ip;
private int port;
// ... getter and setters
}
}

The preceding example produces metadata information for server.name , server.host.ip , and server.host.port properties. You can use
the @NestedConfigurationProperty annotation on a field to indicate that a regular (non-inner) class should be treated as if it were nested.

This has no effect on collections and maps, as those types are automatically identified, and a single metadata property is generated
for each of them.

B.3.2 Adding Additional Metadata
Spring Boot’s configuration file handling is quite flexible, and it is often the case that properties may exist that are not bound to a
@ConfigurationProperties bean. You may also need to tune some attributes of an existing key. To support such cases and let you provide

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custom "hints", the annotation processor automatically merges items from META-INF/additional-spring-configuration-metadata.json into
the main metadata file.
If you refer to a property that has been detected automatically, the description, default value, and deprecation information are overridden, if
specified. If the manual property declaration is not identified in the current module, it is added as a new property.
The format of the additional-spring-configuration-metadata.json file is exactly the same as the regular
spring-configuration-metadata.json . The additional properties file is optional. If you do not have any additional properties, do not add the file.

Appendix C. Auto-configuration classes
Here is a list of all auto-configuration classes provided by Spring Boot, with links to documentation and source code. Remember to also look at the
conditions report in your application for more details of which features are switched on. (To do so, start the app with --debug or -Ddebug or, in an
Actuator application, use the conditions endpoint).

C.1 From the “spring-boot-autoconfigure” module
The following auto-configuration classes are from the spring-boot-autoconfigure module:
Configuration Class

Links

ActiveMQAutoConfiguration

javadoc

AopAutoConfiguration

javadoc

ArtemisAutoConfiguration

javadoc

BatchAutoConfiguration

javadoc

CacheAutoConfiguration

javadoc

CassandraAutoConfiguration

javadoc

CassandraDataAutoConfiguration

javadoc

CassandraReactiveDataAutoConfiguration

javadoc

CassandraReactiveRepositoriesAutoConfiguration

javadoc

CassandraRepositoriesAutoConfiguration

javadoc

ClientHttpConnectorAutoConfiguration

javadoc

CloudServiceConnectorsAutoConfiguration

javadoc

CodecsAutoConfiguration

javadoc

ConfigurationPropertiesAutoConfiguration

javadoc

CouchbaseAutoConfiguration

javadoc

CouchbaseDataAutoConfiguration

javadoc

CouchbaseReactiveDataAutoConfiguration

javadoc

CouchbaseReactiveRepositoriesAutoConfiguration

javadoc

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Configuration Class

Links

CouchbaseRepositoriesAutoConfiguration

javadoc

DataSourceAutoConfiguration

javadoc

DataSourceTransactionManagerAutoConfiguration

javadoc

DispatcherServletAutoConfiguration

javadoc

ElasticsearchAutoConfiguration

javadoc

ElasticsearchDataAutoConfiguration

javadoc

ElasticsearchRepositoriesAutoConfiguration

javadoc

EmbeddedLdapAutoConfiguration

javadoc

EmbeddedMongoAutoConfiguration

javadoc

EmbeddedWebServerFactoryCustomizerAutoConfiguration

javadoc

ErrorMvcAutoConfiguration

javadoc

ErrorWebFluxAutoConfiguration

javadoc

FlywayAutoConfiguration

javadoc

FreeMarkerAutoConfiguration

javadoc

GroovyTemplateAutoConfiguration

javadoc

GsonAutoConfiguration

javadoc

H2ConsoleAutoConfiguration

javadoc

HazelcastAutoConfiguration

javadoc

HazelcastJpaDependencyAutoConfiguration

javadoc

HibernateJpaAutoConfiguration

javadoc

HttpEncodingAutoConfiguration

javadoc

HttpHandlerAutoConfiguration

javadoc

HttpMessageConvertersAutoConfiguration

javadoc

HypermediaAutoConfiguration

javadoc

InfluxDbAutoConfiguration

javadoc

IntegrationAutoConfiguration

javadoc

JacksonAutoConfiguration

javadoc

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Configuration Class

Links

JdbcRepositoriesAutoConfiguration

javadoc

JdbcTemplateAutoConfiguration

javadoc

JerseyAutoConfiguration

javadoc

JestAutoConfiguration

javadoc

JmsAutoConfiguration

javadoc

JmxAutoConfiguration

javadoc

JndiConnectionFactoryAutoConfiguration

javadoc

JndiDataSourceAutoConfiguration

javadoc

JooqAutoConfiguration

javadoc

JpaRepositoriesAutoConfiguration

javadoc

JsonbAutoConfiguration

javadoc

JtaAutoConfiguration

javadoc

KafkaAutoConfiguration

javadoc

LdapAutoConfiguration

javadoc

LdapRepositoriesAutoConfiguration

javadoc

LiquibaseAutoConfiguration

javadoc

MailSenderAutoConfiguration

javadoc

MailSenderValidatorAutoConfiguration

javadoc

MessageSourceAutoConfiguration

javadoc

MongoAutoConfiguration

javadoc

MongoDataAutoConfiguration

javadoc

MongoReactiveAutoConfiguration

javadoc

MongoReactiveDataAutoConfiguration

javadoc

MongoReactiveRepositoriesAutoConfiguration

javadoc

MongoRepositoriesAutoConfiguration

javadoc

MultipartAutoConfiguration

javadoc

MustacheAutoConfiguration

javadoc

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Configuration Class

Links

Neo4jDataAutoConfiguration

javadoc

Neo4jRepositoriesAutoConfiguration

javadoc

OAuth2ClientAutoConfiguration

javadoc

OAuth2ResourceServerAutoConfiguration

javadoc

PersistenceExceptionTranslationAutoConfiguration

javadoc

ProjectInfoAutoConfiguration

javadoc

PropertyPlaceholderAutoConfiguration

javadoc

QuartzAutoConfiguration

javadoc

RabbitAutoConfiguration

javadoc

ReactiveOAuth2ClientAutoConfiguration

javadoc

ReactiveOAuth2ResourceServerAutoConfiguration

javadoc

ReactiveSecurityAutoConfiguration

javadoc

ReactiveUserDetailsServiceAutoConfiguration

javadoc

ReactiveWebServerFactoryAutoConfiguration

javadoc

ReactorCoreAutoConfiguration

javadoc

RedisAutoConfiguration

javadoc

RedisReactiveAutoConfiguration

javadoc

RedisRepositoriesAutoConfiguration

javadoc

RepositoryRestMvcAutoConfiguration

javadoc

RestClientAutoConfiguration

javadoc

RestTemplateAutoConfiguration

javadoc

SecurityAutoConfiguration

javadoc

SecurityFilterAutoConfiguration

javadoc

SecurityRequestMatcherProviderAutoConfiguration

javadoc

SendGridAutoConfiguration

javadoc

ServletWebServerFactoryAutoConfiguration

javadoc

SessionAutoConfiguration

javadoc

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Configuration Class

Links

SolrAutoConfiguration

javadoc

SolrRepositoriesAutoConfiguration

javadoc

SpringApplicationAdminJmxAutoConfiguration

javadoc

SpringDataWebAutoConfiguration

javadoc

TaskExecutionAutoConfiguration

javadoc

TaskSchedulingAutoConfiguration

javadoc

ThymeleafAutoConfiguration

javadoc

TransactionAutoConfiguration

javadoc

UserDetailsServiceAutoConfiguration

javadoc

ValidationAutoConfiguration

javadoc

WebClientAutoConfiguration

javadoc

WebFluxAutoConfiguration

javadoc

WebMvcAutoConfiguration

javadoc

WebServiceTemplateAutoConfiguration

javadoc

WebServicesAutoConfiguration

javadoc

WebSocketMessagingAutoConfiguration

javadoc

WebSocketReactiveAutoConfiguration

javadoc

WebSocketServletAutoConfiguration

javadoc

XADataSourceAutoConfiguration

javadoc

C.2 From the “spring-boot-actuator-autoconfigure” module
The following auto-configuration classes are from the spring-boot-actuator-autoconfigure module:
Configuration Class

Links

AppOpticsMetricsExportAutoConfiguration

javadoc

AtlasMetricsExportAutoConfiguration

javadoc

AuditAutoConfiguration

javadoc

AuditEventsEndpointAutoConfiguration

javadoc

BeansEndpointAutoConfiguration

javadoc

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Configuration Class

Links

CacheMetricsAutoConfiguration

javadoc

CachesEndpointAutoConfiguration

javadoc

CassandraHealthIndicatorAutoConfiguration

javadoc

CassandraReactiveHealthIndicatorAutoConfiguration

javadoc

CloudFoundryActuatorAutoConfiguration

javadoc

CompositeMeterRegistryAutoConfiguration

javadoc

ConditionsReportEndpointAutoConfiguration

javadoc

ConfigurationPropertiesReportEndpointAutoConfiguration

javadoc

CouchbaseHealthIndicatorAutoConfiguration

javadoc

CouchbaseReactiveHealthIndicatorAutoConfiguration

javadoc

DataSourceHealthIndicatorAutoConfiguration

javadoc

DataSourcePoolMetricsAutoConfiguration

javadoc

DatadogMetricsExportAutoConfiguration

javadoc

DiskSpaceHealthIndicatorAutoConfiguration

javadoc

DynatraceMetricsExportAutoConfiguration

javadoc

ElasticMetricsExportAutoConfiguration

javadoc

ElasticSearchClientHealthIndicatorAutoConfiguration

javadoc

ElasticSearchJestHealthIndicatorAutoConfiguration

javadoc

ElasticSearchRestHealthIndicatorAutoConfiguration

javadoc

EndpointAutoConfiguration

javadoc

EnvironmentEndpointAutoConfiguration

javadoc

FlywayEndpointAutoConfiguration

javadoc

GangliaMetricsExportAutoConfiguration

javadoc

GraphiteMetricsExportAutoConfiguration

javadoc

HealthEndpointAutoConfiguration

javadoc

HealthIndicatorAutoConfiguration

javadoc

HeapDumpWebEndpointAutoConfiguration

javadoc

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Configuration Class

Links

HibernateMetricsAutoConfiguration

javadoc

HttpClientMetricsAutoConfiguration

javadoc

HttpTraceAutoConfiguration

javadoc

HttpTraceEndpointAutoConfiguration

javadoc

HumioMetricsExportAutoConfiguration

javadoc

InfluxDbHealthIndicatorAutoConfiguration

javadoc

InfluxMetricsExportAutoConfiguration

javadoc

InfoContributorAutoConfiguration

javadoc

InfoEndpointAutoConfiguration

javadoc

IntegrationGraphEndpointAutoConfiguration

javadoc

JerseyServerMetricsAutoConfiguration

javadoc

JettyMetricsAutoConfiguration

javadoc

JmsHealthIndicatorAutoConfiguration

javadoc

JmxEndpointAutoConfiguration

javadoc

JmxMetricsExportAutoConfiguration

javadoc

JolokiaEndpointAutoConfiguration

javadoc

JvmMetricsAutoConfiguration

javadoc

KafkaMetricsAutoConfiguration

javadoc

KairosMetricsExportAutoConfiguration

javadoc

LdapHealthIndicatorAutoConfiguration

javadoc

LiquibaseEndpointAutoConfiguration

javadoc

Log4J2MetricsAutoConfiguration

javadoc

LogFileWebEndpointAutoConfiguration

javadoc

LogbackMetricsAutoConfiguration

javadoc

LoggersEndpointAutoConfiguration

javadoc

MailHealthIndicatorAutoConfiguration

javadoc

ManagementContextAutoConfiguration

javadoc

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Configuration Class

Links

ManagementWebSecurityAutoConfiguration

javadoc

MappingsEndpointAutoConfiguration

javadoc

MetricsAutoConfiguration

javadoc

MetricsEndpointAutoConfiguration

javadoc

MongoHealthIndicatorAutoConfiguration

javadoc

MongoReactiveHealthIndicatorAutoConfiguration

javadoc

Neo4jHealthIndicatorAutoConfiguration

javadoc

NewRelicMetricsExportAutoConfiguration

javadoc

PrometheusMetricsExportAutoConfiguration

javadoc

RabbitHealthIndicatorAutoConfiguration

javadoc

RabbitMetricsAutoConfiguration

javadoc

ReactiveCloudFoundryActuatorAutoConfiguration

javadoc

ReactiveManagementContextAutoConfiguration

javadoc

ReactiveManagementWebSecurityAutoConfiguration

javadoc

RedisHealthIndicatorAutoConfiguration

javadoc

RedisReactiveHealthIndicatorAutoConfiguration

javadoc

ScheduledTasksEndpointAutoConfiguration

javadoc

ServletManagementContextAutoConfiguration

javadoc

SessionsEndpointAutoConfiguration

javadoc

ShutdownEndpointAutoConfiguration

javadoc

SignalFxMetricsExportAutoConfiguration

javadoc

SimpleMetricsExportAutoConfiguration

javadoc

SolrHealthIndicatorAutoConfiguration

javadoc

StatsdMetricsExportAutoConfiguration

javadoc

SystemMetricsAutoConfiguration

javadoc

ThreadDumpEndpointAutoConfiguration

javadoc

TomcatMetricsAutoConfiguration

javadoc

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Configuration Class

Links

WavefrontMetricsExportAutoConfiguration

javadoc

WebEndpointAutoConfiguration

javadoc

WebFluxMetricsAutoConfiguration

javadoc

WebMvcMetricsAutoConfiguration

javadoc

Appendix D. Test auto-configuration annotations
The following table lists the various @…Test annotations that can be used to test slices of your application and the auto-configuration that they
import by default:
Test slice

Imported auto-configuration

@DataJdbcTest

org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration
org.springframework.boot.autoconfigure.data.jdbc.JdbcRepositoriesAutoConfiguration
org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration
org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration
org.springframework.boot.autoconfigure.jdbc.DataSourceTransactionManagerAutoConfiguration
org.springframework.boot.autoconfigure.jdbc.JdbcTemplateAutoConfiguration
org.springframework.boot.autoconfigure.liquibase.LiquibaseAutoConfiguration
org.springframework.boot.autoconfigure.transaction.TransactionAutoConfiguration
org.springframework.boot.test.autoconfigure.jdbc.TestDatabaseAutoConfiguration

@DataJpaTest

org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration
org.springframework.boot.autoconfigure.data.jpa.JpaRepositoriesAutoConfiguration
org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration
org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration
org.springframework.boot.autoconfigure.jdbc.DataSourceTransactionManagerAutoConfiguration
org.springframework.boot.autoconfigure.jdbc.JdbcTemplateAutoConfiguration
org.springframework.boot.autoconfigure.liquibase.LiquibaseAutoConfiguration
org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration
org.springframework.boot.autoconfigure.transaction.TransactionAutoConfiguration
org.springframework.boot.test.autoconfigure.jdbc.TestDatabaseAutoConfiguration
org.springframework.boot.test.autoconfigure.orm.jpa.TestEntityManagerAutoConfiguration

@DataLdapTest

org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration
org.springframework.boot.autoconfigure.data.ldap.LdapRepositoriesAutoConfiguration
org.springframework.boot.autoconfigure.ldap.LdapAutoConfiguration
org.springframework.boot.autoconfigure.ldap.embedded.EmbeddedLdapAutoConfiguration

@DataMongoTest

org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration
org.springframework.boot.autoconfigure.data.mongo.MongoDataAutoConfiguration
org.springframework.boot.autoconfigure.data.mongo.MongoReactiveDataAutoConfiguration
org.springframework.boot.autoconfigure.data.mongo.MongoReactiveRepositoriesAutoConfiguration
org.springframework.boot.autoconfigure.data.mongo.MongoRepositoriesAutoConfiguration
org.springframework.boot.autoconfigure.mongo.MongoAutoConfiguration
org.springframework.boot.autoconfigure.mongo.MongoReactiveAutoConfiguration
org.springframework.boot.autoconfigure.mongo.embedded.EmbeddedMongoAutoConfiguration

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Test slice

Imported auto-configuration

@DataNeo4jTest

org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration
org.springframework.boot.autoconfigure.data.neo4j.Neo4jDataAutoConfiguration
org.springframework.boot.autoconfigure.data.neo4j.Neo4jRepositoriesAutoConfiguration
org.springframework.boot.autoconfigure.transaction.TransactionAutoConfiguration

@DataRedisTest

org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration
org.springframework.boot.autoconfigure.data.redis.RedisAutoConfiguration
org.springframework.boot.autoconfigure.data.redis.RedisRepositoriesAutoConfiguration

@JdbcTest

org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration
org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration
org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration
org.springframework.boot.autoconfigure.jdbc.DataSourceTransactionManagerAutoConfiguration
org.springframework.boot.autoconfigure.jdbc.JdbcTemplateAutoConfiguration
org.springframework.boot.autoconfigure.liquibase.LiquibaseAutoConfiguration
org.springframework.boot.autoconfigure.transaction.TransactionAutoConfiguration
org.springframework.boot.test.autoconfigure.jdbc.TestDatabaseAutoConfiguration

@JooqTest

org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration
org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration
org.springframework.boot.autoconfigure.jdbc.DataSourceTransactionManagerAutoConfiguration
org.springframework.boot.autoconfigure.jooq.JooqAutoConfiguration
org.springframework.boot.autoconfigure.liquibase.LiquibaseAutoConfiguration
org.springframework.boot.autoconfigure.transaction.TransactionAutoConfiguration

@JsonTest

org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration
org.springframework.boot.autoconfigure.gson.GsonAutoConfiguration
org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration
org.springframework.boot.autoconfigure.jsonb.JsonbAutoConfiguration
org.springframework.boot.test.autoconfigure.json.JsonTestersAutoConfiguration

@RestClientTest

org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration
org.springframework.boot.autoconfigure.gson.GsonAutoConfiguration
org.springframework.boot.autoconfigure.http.HttpMessageConvertersAutoConfiguration
org.springframework.boot.autoconfigure.http.codec.CodecsAutoConfiguration
org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration
org.springframework.boot.autoconfigure.jsonb.JsonbAutoConfiguration
org.springframework.boot.autoconfigure.web.client.RestTemplateAutoConfiguration
org.springframework.boot.autoconfigure.web.reactive.function.client.WebClientAutoConfiguration
org.springframework.boot.test.autoconfigure.web.client.MockRestServiceServerAutoConfiguration
org.springframework.boot.test.autoconfigure.web.client.WebClientRestTemplateAutoConfiguration

@WebFluxTest

org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration
org.springframework.boot.autoconfigure.context.MessageSourceAutoConfiguration
org.springframework.boot.autoconfigure.gson.GsonAutoConfiguration
org.springframework.boot.autoconfigure.http.codec.CodecsAutoConfiguration
org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration
org.springframework.boot.autoconfigure.jsonb.JsonbAutoConfiguration
org.springframework.boot.autoconfigure.security.reactive.ReactiveSecurityAutoConfiguration
org.springframework.boot.autoconfigure.security.reactive.ReactiveUserDetailsServiceAutoConfiguration
org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration
org.springframework.boot.autoconfigure.web.reactive.WebFluxAutoConfiguration
org.springframework.boot.test.autoconfigure.web.reactive.WebTestClientAutoConfiguration

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Test slice

Imported auto-configuration

@WebMvcTest

org.springframework.boot.autoconfigure.cache.CacheAutoConfiguration
org.springframework.boot.autoconfigure.context.MessageSourceAutoConfiguration
org.springframework.boot.autoconfigure.data.web.SpringDataWebAutoConfiguration
org.springframework.boot.autoconfigure.freemarker.FreeMarkerAutoConfiguration
org.springframework.boot.autoconfigure.groovy.template.GroovyTemplateAutoConfiguration
org.springframework.boot.autoconfigure.gson.GsonAutoConfiguration
org.springframework.boot.autoconfigure.hateoas.HypermediaAutoConfiguration
org.springframework.boot.autoconfigure.http.HttpMessageConvertersAutoConfiguration
org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration
org.springframework.boot.autoconfigure.jsonb.JsonbAutoConfiguration
org.springframework.boot.autoconfigure.mustache.MustacheAutoConfiguration
org.springframework.boot.autoconfigure.task.TaskExecutionAutoConfiguration
org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration
org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration
org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration
org.springframework.boot.autoconfigure.web.servlet.error.ErrorMvcAutoConfiguration
org.springframework.boot.test.autoconfigure.web.servlet.MockMvcAutoConfiguration
org.springframework.boot.test.autoconfigure.web.servlet.MockMvcSecurityAutoConfiguration
org.springframework.boot.test.autoconfigure.web.servlet.MockMvcWebClientAutoConfiguration
org.springframework.boot.test.autoconfigure.web.servlet.MockMvcWebDriverAutoConfiguration

Appendix E. The Executable Jar Format
The spring-boot-loader modules lets Spring Boot support executable jar and war files. If you use the Maven plugin or the Gradle plugin,
executable jars are automatically generated, and you generally do not need to know the details of how they work.
If you need to create executable jars from a different build system or if you are just curious about the underlying technology, this section provides
some background.

E.1 Nested JARs
Java does not provide any standard way to load nested jar files (that is, jar files that are themselves contained within a jar). This can be problematic
if you need to distribute a self-contained application that can be run from the command line without unpacking.
To solve this problem, many developers use “shaded” jars. A shaded jar packages all classes, from all jars, into a single “uber jar”. The problem with
shaded jars is that it becomes hard to see which libraries are actually in your application. It can also be problematic if the same filename is used (but
with different content) in multiple jars. Spring Boot takes a different approach and lets you actually nest jars directly.

E.1.1 The Executable Jar File Structure
Spring Boot Loader-compatible jar files should be structured in the following way:
example.jar
|
+-META-INF
| +-MANIFEST.MF
+-org
| +-springframework
|
+-boot
|
+-loader
|
+-
+-BOOT-INF
+-classes
| +-mycompany
|
+-project
|
+-YourClasses.class
+-lib

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+-dependency1.jar
+-dependency2.jar

Application classes should be placed in a nested BOOT-INF/classes directory. Dependencies should be placed in a nested BOOT-INF/lib
directory.

E.1.2 The Executable War File Structure
Spring Boot Loader-compatible war files should be structured in the following way:
example.war
|
+-META-INF
| +-MANIFEST.MF
+-org
| +-springframework
|
+-boot
|
+-loader
|
+-
+-WEB-INF
+-classes
| +-com
|
+-mycompany
|
+-project
|
+-YourClasses.class
+-lib
| +-dependency1.jar
| +-dependency2.jar
+-lib-provided
+-servlet-api.jar
+-dependency3.jar

Dependencies should be placed in a nested WEB-INF/lib directory. Any dependencies that are required when running embedded but are not
required when deploying to a traditional web container should be placed in WEB-INF/lib-provided .

E.2 Spring Boot’s “JarFile” Class
The core class used to support loading nested jars is org.springframework.boot.loader.jar.JarFile . It lets you load jar content from a
standard jar file or from nested child jar data. When first loaded, the location of each JarEntry is mapped to a physical file offset of the outer jar, as
shown in the following example:
myapp.jar
+-------------------+-------------------------+
| /BOOT-INF/classes | /BOOT-INF/lib/mylib.jar |
|+-----------------+||+-----------+----------+|
||
A.class
||| B.class | C.class ||
|+-----------------+||+-----------+----------+|
+-------------------+-------------------------+
^
^
^
0063
3452
3980

The preceding example shows how A.class can be found in /BOOT-INF/classes in myapp.jar at position 0063 . B.class from the nested
jar can actually be found in myapp.jar at position 3452 , and C.class is at position 3980 .
Armed with this information, we can load specific nested entries by seeking to the appropriate part of the outer jar. We do not need to unpack the
archive, and we do not need to read all entry data into memory.

E.2.1 Compatibility with the Standard Java “JarFile”
Spring Boot Loader strives to remain compatible with existing code and libraries. org.springframework.boot.loader.jar.JarFile extends
from java.util.jar.JarFile and should work as a drop-in replacement. The getURL() method returns a URL that opens a connection
compatible with java.net.JarURLConnection and can be used with Java’s URLClassLoader .

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E.3 Launching Executable Jars
The org.springframework.boot.loader.Launcher class is a special bootstrap class that is used as an executable jar’s main entry point. It is
the actual Main-Class in your jar file, and it is used to setup an appropriate URLClassLoader and ultimately call your main() method.
There are three launcher subclasses ( JarLauncher , WarLauncher , and PropertiesLauncher ). Their purpose is to load resources ( .class
files and so on.) from nested jar files or war files in directories (as opposed to those explicitly on the classpath). In the case of JarLauncher and
WarLauncher , the nested paths are fixed. JarLauncher looks in BOOT-INF/lib/ , and WarLauncher looks in WEB-INF/lib/ and
WEB-INF/lib-provided/ . You can add extra jars in those locations if you want more. The PropertiesLauncher looks in BOOT-INF/lib/ in
your application archive by default, but you can add additional locations by setting an environment variable called LOADER_PATH or loader.path
in loader.properties (which is a comma-separated list of directories, archives, or directories within archives).

E.3.1 Launcher Manifest
You need to specify an appropriate Launcher as the Main-Class attribute of META-INF/MANIFEST.MF . The actual class that you want to launch
(that is, the class that contains a main method) should be specified in the Start-Class attribute.
The following example shows a typical MANIFEST.MF for an executable jar file:
Main-Class: org.springframework.boot.loader.JarLauncher
Start-Class: com.mycompany.project.MyApplication

For a war file, it would be as follows:
Main-Class: org.springframework.boot.loader.WarLauncher
Start-Class: com.mycompany.project.MyApplication

You need not specify Class-Path entries in your manifest file. The classpath is deduced from the nested jars.

E.3.2 Exploded Archives
Certain PaaS implementations may choose to unpack archives before they run. For example, Cloud Foundry operates this way. You can run an
unpacked archive by starting the appropriate launcher, as follows:
$ unzip -q myapp.jar
$ java org.springframework.boot.loader.JarLauncher

E.4 PropertiesLauncher Features
PropertiesLauncher has a few special features that can be enabled with external properties (System properties, environment variables, manifest
entries, or loader.properties ). The following table describes these properties:
Key

Purpose

loader.path

Comma-separated Classpath, such as lib,${HOME}/app/lib . Earlier entries take precedence, like a regular
-classpath on the javac command line.

loader.home

Used to resolve relative paths in loader.path . For example, given loader.path=lib , then
${loader.home}/lib is a classpath location (along with all jar files in that directory). This property is also
used to locate a loader.properties file, as in the following example /opt/app It defaults to ${user.dir} .

loader.args

Default arguments for the main method (space separated).

loader.main

Name of main class to launch (for example, com.app.Application ).

loader.config.name

Name of properties file (for example, launcher ) It defaults to loader .

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Key

Purpose

loader.config.location

Path to properties file (for example, classpath:loader.properties ). It defaults to loader.properties .

loader.system

Boolean flag to indicate that all properties should be added to System properties It defaults to false .

When specified as environment variables or manifest entries, the following names should be used:
Key

Manifest entry

Environment variable

loader.path

Loader-Path

LOADER_PATH

loader.home

Loader-Home

LOADER_HOME

loader.args

Loader-Args

LOADER_ARGS

loader.main

Start-Class

LOADER_MAIN

loader.config.location

Loader-Config-Location

LOADER_CONFIG_LOCATION

loader.system

Loader-System

LOADER_SYSTEM

Build plugins automatically move the Main-Class attribute to Start-Class when the fat jar is built. If you use that, specify the name
of the class to launch by using the Main-Class attribute and leaving out Start-Class .

The following rules apply to working with PropertiesLauncher :
loader.properties is searched for in loader.home , then in the root of the classpath, and then in classpath:/BOOT-INF/classes . The
first location where a file with that name exists is used.
loader.home is the directory location of an additional properties file (overriding the default) only when loader.config.location is not
specified.
loader.path can contain directories (which are scanned recursively for jar and zip files), archive paths, a directory within an archive that is
scanned for jar files (for example, dependencies.jar!/lib ), or wildcard patterns (for the default JVM behavior). Archive paths can be relative
to loader.home or anywhere in the file system with a jar:file: prefix.
loader.path (if empty) defaults to BOOT-INF/lib (meaning a local directory or a nested one if running from an archive). Because of this,
PropertiesLauncher behaves the same as JarLauncher when no additional configuration is provided.
loader.path can not be used to configure the location of loader.properties (the classpath used to search for the latter is the JVM
classpath when PropertiesLauncher is launched).
Placeholder replacement is done from System and environment variables plus the properties file itself on all values before use.
The search order for properties (where it makes sense to look in more than one place) is environment variables, system properties,
loader.properties , the exploded archive manifest, and the archive manifest.

E.5 Executable Jar Restrictions
You need to consider the following restrictions when working with a Spring Boot Loader packaged application:
Zip entry compression: The ZipEntry for a nested jar must be saved by using the ZipEntry.STORED method. This is required so that we can
seek directly to individual content within the nested jar. The content of the nested jar file itself can still be compressed, as can any other entries
in the outer jar.
System classLoader: Launched applications should use Thread.getContextClassLoader() when loading classes (most libraries and
frameworks do so by default). Trying to load nested jar classes with ClassLoader.getSystemClassLoader() fails. java.util.Logging
always uses the system classloader. For this reason, you should consider a different logging implementation.

E.6 Alternative Single Jar Solutions
If the preceding restrictions mean that you cannot use Spring Boot Loader, consider the following alternatives:
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Maven Shade Plugin
JarClassLoader
OneJar
Gradle Shadow Plugin

Appendix F. Dependency versions
The following table provides details of all of the dependency versions that are provided by Spring Boot in its CLI (Command Line Interface), Maven
dependency management, and Gradle plugin. When you declare a dependency on one of these artifacts without declaring a version, the version
listed in the table is used.
Group ID

Artifact ID

Version

antlr

antlr

2.7.7

ch.qos.logback

logback-access

1.2.3

ch.qos.logback

logback-classic

1.2.3

ch.qos.logback

logback-core

1.2.3

com.atomikos

transactions-jdbc

4.0.6

com.atomikos

transactions-jms

4.0.6

com.atomikos

transactions-jta

4.0.6

com.couchbase.client

couchbase-spring-cache

2.1.0

com.couchbase.client

java-client

2.7.1

com.datastax.cassandra

cassandra-driver-core

3.6.0

com.datastax.cassandra

cassandra-driver-mapping

3.6.0

com.fasterxml

classmate

1.4.0

com.fasterxml.jackson.core

jackson-annotations

2.9.0

com.fasterxml.jackson.core

jackson-core

2.9.7

com.fasterxml.jackson.core

jackson-databind

2.9.7

com.fasterxml.jackson.dataformat

jackson-dataformat-avro

2.9.7

com.fasterxml.jackson.dataformat

jackson-dataformat-cbor

2.9.7

com.fasterxml.jackson.dataformat

jackson-dataformat-csv

2.9.7

com.fasterxml.jackson.dataformat

jackson-dataformat-ion

2.9.7

com.fasterxml.jackson.dataformat

jackson-dataformat-properties

2.9.7

com.fasterxml.jackson.dataformat

jackson-dataformat-protobuf

2.9.7

com.fasterxml.jackson.dataformat

jackson-dataformat-smile

2.9.7

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Group ID

Artifact ID

Version

com.fasterxml.jackson.dataformat

jackson-dataformat-xml

2.9.7

com.fasterxml.jackson.dataformat

jackson-dataformat-yaml

2.9.7

com.fasterxml.jackson.datatype

jackson-datatype-guava

2.9.7

com.fasterxml.jackson.datatype

jackson-datatype-hibernate3

2.9.7

com.fasterxml.jackson.datatype

jackson-datatype-hibernate4

2.9.7

com.fasterxml.jackson.datatype

jackson-datatype-hibernate5

2.9.7

com.fasterxml.jackson.datatype

jackson-datatype-hppc

2.9.7

com.fasterxml.jackson.datatype

jackson-datatype-jaxrs

2.9.7

com.fasterxml.jackson.datatype

jackson-datatype-jdk8

2.9.7

com.fasterxml.jackson.datatype

jackson-datatype-joda

2.9.7

com.fasterxml.jackson.datatype

jackson-datatype-json-org

2.9.7

com.fasterxml.jackson.datatype

jackson-datatype-jsr310

2.9.7

com.fasterxml.jackson.datatype

jackson-datatype-jsr353

2.9.7

com.fasterxml.jackson.datatype

jackson-datatype-pcollections

2.9.7

com.fasterxml.jackson.jaxrs

jackson-jaxrs-base

2.9.7

com.fasterxml.jackson.jaxrs

jackson-jaxrs-cbor-provider

2.9.7

com.fasterxml.jackson.jaxrs

jackson-jaxrs-json-provider

2.9.7

com.fasterxml.jackson.jaxrs

jackson-jaxrs-smile-provider

2.9.7

com.fasterxml.jackson.jaxrs

jackson-jaxrs-xml-provider

2.9.7

com.fasterxml.jackson.jaxrs

jackson-jaxrs-yaml-provider

2.9.7

com.fasterxml.jackson.jr

jackson-jr-all

2.9.7

com.fasterxml.jackson.jr

jackson-jr-objects

2.9.7

com.fasterxml.jackson.jr

jackson-jr-retrofit2

2.9.7

com.fasterxml.jackson.jr

jackson-jr-stree

2.9.7

com.fasterxml.jackson.module

jackson-module-afterburner

2.9.7

com.fasterxml.jackson.module

jackson-module-guice

2.9.7

com.fasterxml.jackson.module

jackson-module-jaxb-annotations

2.9.7

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Group ID

Artifact ID

Version

com.fasterxml.jackson.module

jackson-module-jsonSchema

2.9.7

com.fasterxml.jackson.module

jackson-module-kotlin

2.9.7

com.fasterxml.jackson.module

jackson-module-mrbean

2.9.7

com.fasterxml.jackson.module

jackson-module-osgi

2.9.7

com.fasterxml.jackson.module

jackson-module-parameter-names

2.9.7

com.fasterxml.jackson.module

jackson-module-paranamer

2.9.7

com.fasterxml.jackson.module

jackson-module-scala_2.10

2.9.7

com.fasterxml.jackson.module

jackson-module-scala_2.11

2.9.7

com.fasterxml.jackson.module

jackson-module-scala_2.12

2.9.7

com.github.ben-manes.caffeine

caffeine

2.6.2

com.github.ben-manes.caffeine

guava

2.6.2

com.github.ben-manes.caffeine

jcache

2.6.2

com.github.ben-manes.caffeine

simulator

2.6.2

com.github.mxab.thymeleaf.extras

thymeleaf-extras-data-attribute

2.0.1

com.google.appengine

appengine-api-1.0-sdk

1.9.68

com.google.code.gson

gson

2.8.5

com.h2database

h2

1.4.197

com.hazelcast

hazelcast

3.11

com.hazelcast

hazelcast-client

3.11

com.hazelcast

hazelcast-hibernate52

1.2.3

com.hazelcast

hazelcast-spring

3.11

com.jayway.jsonpath

json-path

2.4.0

com.jayway.jsonpath

json-path-assert

2.4.0

com.microsoft.sqlserver

mssql-jdbc

6.4.0.jre8

com.querydsl

querydsl-apt

4.2.1

com.querydsl

querydsl-collections

4.2.1

com.querydsl

querydsl-core

4.2.1

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Group ID

Artifact ID

Version

com.querydsl

querydsl-jpa

4.2.1

com.querydsl

querydsl-mongodb

4.2.1

com.rabbitmq

amqp-client

5.4.3

com.samskivert

jmustache

1.14

com.sendgrid

sendgrid-java

4.3.0

com.sun.mail

javax.mail

1.6.2

com.sun.xml.messaging.saaj

saaj-impl

1.5.0

com.timgroup

java-statsd-client

3.1.0

com.unboundid

unboundid-ldapsdk

4.0.9

com.zaxxer

HikariCP

3.2.0

commons-codec

commons-codec

1.11

commons-pool

commons-pool

1.6

de.flapdoodle.embed

de.flapdoodle.embed.mongo

2.1.1

dom4j

dom4j

1.6.1

io.dropwizard.metrics

metrics-annotation

4.0.3

io.dropwizard.metrics

metrics-core

4.0.3

io.dropwizard.metrics

metrics-ehcache

4.0.3

io.dropwizard.metrics

metrics-graphite

4.0.3

io.dropwizard.metrics

metrics-healthchecks

4.0.3

io.dropwizard.metrics

metrics-httpasyncclient

4.0.3

io.dropwizard.metrics

metrics-jdbi

4.0.3

io.dropwizard.metrics

metrics-jersey

4.0.3

io.dropwizard.metrics

metrics-jersey2

4.0.3

io.dropwizard.metrics

metrics-jetty8

4.0.3

io.dropwizard.metrics

metrics-jetty9

4.0.3

io.dropwizard.metrics

metrics-jetty9-legacy

4.0.3

io.dropwizard.metrics

metrics-jmx

4.0.3

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Group ID

Artifact ID

Version

io.dropwizard.metrics

metrics-json

4.0.3

io.dropwizard.metrics

metrics-jvm

4.0.3

io.dropwizard.metrics

metrics-log4j

4.0.3

io.dropwizard.metrics

metrics-log4j2

4.0.3

io.dropwizard.metrics

metrics-logback

4.0.3

io.dropwizard.metrics

metrics-servlet

4.0.3

io.dropwizard.metrics

metrics-servlets

4.0.3

io.lettuce

lettuce-core

5.1.3.RELEASE

io.micrometer

micrometer-core

1.1.1

io.micrometer

micrometer-jersey2

1.1.1

io.micrometer

micrometer-registry-appoptics

1.1.1

io.micrometer

micrometer-registry-atlas

1.1.1

io.micrometer

micrometer-registry-azure-monitor

1.1.1

io.micrometer

micrometer-registry-cloudwatch

1.1.1

io.micrometer

micrometer-registry-datadog

1.1.1

io.micrometer

micrometer-registry-dynatrace

1.1.1

io.micrometer

micrometer-registry-elastic

1.1.1

io.micrometer

micrometer-registry-ganglia

1.1.1

io.micrometer

micrometer-registry-graphite

1.1.1

io.micrometer

micrometer-registry-humio

1.1.1

io.micrometer

micrometer-registry-influx

1.1.1

io.micrometer

micrometer-registry-jmx

1.1.1

io.micrometer

micrometer-registry-kairos

1.1.1

io.micrometer

micrometer-registry-new-relic

1.1.1

io.micrometer

micrometer-registry-prometheus

1.1.1

io.micrometer

micrometer-registry-signalfx

1.1.1

io.micrometer

micrometer-registry-statsd

1.1.1

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Group ID

Artifact ID

Version

io.micrometer

micrometer-registry-wavefront

1.1.1

io.micrometer

micrometer-test

1.1.1

io.netty

netty-all

4.1.31.Final

io.netty

netty-buffer

4.1.31.Final

io.netty

netty-codec

4.1.31.Final

io.netty

netty-codec-dns

4.1.31.Final

io.netty

netty-codec-haproxy

4.1.31.Final

io.netty

netty-codec-http

4.1.31.Final

io.netty

netty-codec-http2

4.1.31.Final

io.netty

netty-codec-memcache

4.1.31.Final

io.netty

netty-codec-mqtt

4.1.31.Final

io.netty

netty-codec-redis

4.1.31.Final

io.netty

netty-codec-smtp

4.1.31.Final

io.netty

netty-codec-socks

4.1.31.Final

io.netty

netty-codec-stomp

4.1.31.Final

io.netty

netty-codec-xml

4.1.31.Final

io.netty

netty-common

4.1.31.Final

io.netty

netty-dev-tools

4.1.31.Final

io.netty

netty-example

4.1.31.Final

io.netty

netty-handler

4.1.31.Final

io.netty

netty-handler-proxy

4.1.31.Final

io.netty

netty-resolver

4.1.31.Final

io.netty

netty-resolver-dns

4.1.31.Final

io.netty

netty-tcnative-boringssl-static

2.0.20.Final

io.netty

netty-transport

4.1.31.Final

io.netty

netty-transport-native-epoll

4.1.31.Final

io.netty

netty-transport-native-kqueue

4.1.31.Final

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Group ID

Artifact ID

Version

io.netty

netty-transport-native-unix-common

4.1.31.Final

io.netty

netty-transport-rxtx

4.1.31.Final

io.netty

netty-transport-sctp

4.1.31.Final

io.netty

netty-transport-udt

4.1.31.Final

io.projectreactor

reactor-core

3.2.3.RELEASE

io.projectreactor

reactor-test

3.2.3.RELEASE

io.projectreactor.addons

reactor-adapter

3.2.0.RELEASE

io.projectreactor.addons

reactor-extra

3.2.0.RELEASE

io.projectreactor.addons

reactor-logback

3.2.0.RELEASE

io.projectreactor.kafka

reactor-kafka

1.1.0.RELEASE

io.projectreactor.netty

reactor-netty

0.8.3.RELEASE

io.prometheus

simpleclient_pushgateway

0.5.0

io.reactivex

rxjava

1.3.8

io.reactivex

rxjava-reactive-streams

1.2.1

io.reactivex.rxjava2

rxjava

2.2.4

io.rest-assured

json-path

3.1.1

io.rest-assured

json-schema-validator

3.1.1

io.rest-assured

rest-assured

3.1.1

io.rest-assured

scala-support

3.1.1

io.rest-assured

spring-mock-mvc

3.1.1

io.rest-assured

xml-path

3.1.1

io.searchbox

jest

6.3.1

io.undertow

undertow-core

2.0.16.Final

io.undertow

undertow-servlet

2.0.16.Final

io.undertow

undertow-websockets-jsr

2.0.16.Final

javax.activation

javax.activation-api

1.2.0

javax.annotation

javax.annotation-api

1.3.2

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Group ID

Artifact ID

Version

javax.cache

cache-api

1.1.0

javax.jms

javax.jms-api

2.0.1

javax.json

javax.json-api

1.1.4

javax.json.bind

javax.json.bind-api

1.0

javax.mail

javax.mail-api

1.6.2

javax.money

money-api

1.0.3

javax.persistence

javax.persistence-api

2.2

javax.servlet

javax.servlet-api

4.0.1

javax.servlet

jstl

1.2

javax.transaction

javax.transaction-api

1.3

javax.validation

validation-api

2.0.1.Final

javax.websocket

javax.websocket-api

1.1

javax.xml.bind

jaxb-api

2.3.1

javax.xml.ws

jaxws-api

2.3.1

jaxen

jaxen

1.1.6

joda-time

joda-time

2.10.1

junit

junit

4.12

mysql

mysql-connector-java

8.0.13

net.bytebuddy

byte-buddy

1.9.5

net.bytebuddy

byte-buddy-agent

1.9.5

net.java.dev.jna

jna

4.5.2

net.java.dev.jna

jna-platform

4.5.2

net.sf.ehcache

ehcache

2.10.6

net.sourceforge.htmlunit

htmlunit

2.33

net.sourceforge.jtds

jtds

1.3.1

net.sourceforge.nekohtml

nekohtml

1.9.22

nz.net.ultraq.thymeleaf

thymeleaf-layout-dialect

2.3.0

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Group ID

Artifact ID

Version

org.apache.activemq

activemq-amqp

5.15.8

org.apache.activemq

activemq-blueprint

5.15.8

org.apache.activemq

activemq-broker

5.15.8

org.apache.activemq

activemq-camel

5.15.8

org.apache.activemq

activemq-client

5.15.8

org.apache.activemq

activemq-console

5.15.8

org.apache.activemq

activemq-http

5.15.8

org.apache.activemq

activemq-jaas

5.15.8

org.apache.activemq

activemq-jdbc-store

5.15.8

org.apache.activemq

activemq-jms-pool

5.15.8

org.apache.activemq

activemq-kahadb-store

5.15.8

org.apache.activemq

activemq-karaf

5.15.8

org.apache.activemq

activemq-leveldb-store

5.15.8

org.apache.activemq

activemq-log4j-appender

5.15.8

org.apache.activemq

activemq-mqtt

5.15.8

org.apache.activemq

activemq-openwire-generator

5.15.8

org.apache.activemq

activemq-openwire-legacy

5.15.8

org.apache.activemq

activemq-osgi

5.15.8

org.apache.activemq

activemq-partition

5.15.8

org.apache.activemq

activemq-pool

5.15.8

org.apache.activemq

activemq-ra

5.15.8

org.apache.activemq

activemq-run

5.15.8

org.apache.activemq

activemq-runtime-config

5.15.8

org.apache.activemq

activemq-shiro

5.15.8

org.apache.activemq

activemq-spring

5.15.8

org.apache.activemq

activemq-stomp

5.15.8

org.apache.activemq

activemq-web

5.15.8

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Group ID

Artifact ID

Version

org.apache.activemq

artemis-amqp-protocol

2.6.3

org.apache.activemq

artemis-commons

2.6.3

org.apache.activemq

artemis-core-client

2.6.3

org.apache.activemq

artemis-jms-client

2.6.3

org.apache.activemq

artemis-jms-server

2.6.3

org.apache.activemq

artemis-journal

2.6.3

org.apache.activemq

artemis-native

2.6.3

org.apache.activemq

artemis-selector

2.6.3

org.apache.activemq

artemis-server

2.6.3

org.apache.activemq

artemis-service-extensions

2.6.3

org.apache.commons

commons-dbcp2

2.5.0

org.apache.commons

commons-lang3

3.8.1

org.apache.commons

commons-pool2

2.6.0

org.apache.derby

derby

10.14.2.0

org.apache.httpcomponents

fluent-hc

4.5.6

org.apache.httpcomponents

httpasyncclient

4.1.4

org.apache.httpcomponents

httpclient

4.5.6

org.apache.httpcomponents

httpclient-cache

4.5.6

org.apache.httpcomponents

httpclient-osgi

4.5.6

org.apache.httpcomponents

httpclient-win

4.5.6

org.apache.httpcomponents

httpcore

4.4.10

org.apache.httpcomponents

httpcore-nio

4.4.10

org.apache.httpcomponents

httpmime

4.5.6

org.apache.johnzon

johnzon-core

1.1.10

org.apache.johnzon

johnzon-jaxrs

1.1.10

org.apache.johnzon

johnzon-jsonb

1.1.10

org.apache.johnzon

johnzon-jsonb-extras

1.1.10

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Group ID

Artifact ID

Version

org.apache.johnzon

johnzon-jsonschema

1.1.10

org.apache.johnzon

johnzon-mapper

1.1.10

org.apache.johnzon

johnzon-websocket

1.1.10

org.apache.kafka

connect-api

2.0.1

org.apache.kafka

connect-file

2.0.1

org.apache.kafka

connect-json

2.0.1

org.apache.kafka

connect-runtime

2.0.1

org.apache.kafka

connect-transforms

2.0.1

org.apache.kafka

kafka_2.11

2.0.1

org.apache.kafka

kafka_2.12

2.0.1

org.apache.kafka

kafka-clients

2.0.1

org.apache.kafka

kafka-log4j-appender

2.0.1

org.apache.kafka

kafka-streams

2.0.1

org.apache.kafka

kafka-tools

2.0.1

org.apache.logging.log4j

log4j-1.2-api

2.11.1

org.apache.logging.log4j

log4j-api

2.11.1

org.apache.logging.log4j

log4j-cassandra

2.11.1

org.apache.logging.log4j

log4j-core

2.11.1

org.apache.logging.log4j

log4j-couchdb

2.11.1

org.apache.logging.log4j

log4j-flume-ng

2.11.1

org.apache.logging.log4j

log4j-iostreams

2.11.1

org.apache.logging.log4j

log4j-jcl

2.11.1

org.apache.logging.log4j

log4j-jmx-gui

2.11.1

org.apache.logging.log4j

log4j-jpa

2.11.1

org.apache.logging.log4j

log4j-jul

2.11.1

org.apache.logging.log4j

log4j-liquibase

2.11.1

org.apache.logging.log4j

log4j-mongodb2

2.11.1

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Group ID

Artifact ID

Version

org.apache.logging.log4j

log4j-mongodb3

2.11.1

org.apache.logging.log4j

log4j-slf4j-impl

2.11.1

org.apache.logging.log4j

log4j-taglib

2.11.1

org.apache.logging.log4j

log4j-to-slf4j

2.11.1

org.apache.logging.log4j

log4j-web

2.11.1

org.apache.solr

solr-analysis-extras

7.4.0

org.apache.solr

solr-analytics

7.4.0

org.apache.solr

solr-cell

7.4.0

org.apache.solr

solr-clustering

7.4.0

org.apache.solr

solr-core

7.4.0

org.apache.solr

solr-dataimporthandler

7.4.0

org.apache.solr

solr-dataimporthandler-extras

7.4.0

org.apache.solr

solr-langid

7.4.0

org.apache.solr

solr-ltr

7.4.0

org.apache.solr

solr-solrj

7.4.0

org.apache.solr

solr-test-framework

7.4.0

org.apache.solr

solr-uima

7.4.0

org.apache.solr

solr-velocity

7.4.0

org.apache.tomcat

tomcat-annotations-api

9.0.13

org.apache.tomcat

tomcat-catalina-jmx-remote

9.0.13

org.apache.tomcat

tomcat-jdbc

9.0.13

org.apache.tomcat

tomcat-jsp-api

9.0.13

org.apache.tomcat.embed

tomcat-embed-core

9.0.13

org.apache.tomcat.embed

tomcat-embed-el

9.0.13

org.apache.tomcat.embed

tomcat-embed-jasper

9.0.13

org.apache.tomcat.embed

tomcat-embed-websocket

9.0.13

org.aspectj

aspectjrt

1.9.2

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Group ID

Artifact ID

Version

org.aspectj

aspectjtools

1.9.2

org.aspectj

aspectjweaver

1.9.2

org.assertj

assertj-core

3.11.1

org.codehaus.btm

btm

2.1.4

org.codehaus.groovy

groovy

2.5.4

org.codehaus.groovy

groovy-ant

2.5.4

org.codehaus.groovy

groovy-bsf

2.5.4

org.codehaus.groovy

groovy-console

2.5.4

org.codehaus.groovy

groovy-docgenerator

2.5.4

org.codehaus.groovy

groovy-groovydoc

2.5.4

org.codehaus.groovy

groovy-groovysh

2.5.4

org.codehaus.groovy

groovy-jmx

2.5.4

org.codehaus.groovy

groovy-json

2.5.4

org.codehaus.groovy

groovy-jsr223

2.5.4

org.codehaus.groovy

groovy-nio

2.5.4

org.codehaus.groovy

groovy-servlet

2.5.4

org.codehaus.groovy

groovy-sql

2.5.4

org.codehaus.groovy

groovy-swing

2.5.4

org.codehaus.groovy

groovy-templates

2.5.4

org.codehaus.groovy

groovy-test

2.5.4

org.codehaus.groovy

groovy-testng

2.5.4

org.codehaus.groovy

groovy-xml

2.5.4

org.codehaus.janino

janino

3.0.11

org.eclipse.jetty

apache-jsp

9.4.12.v20180830

org.eclipse.jetty

apache-jstl

9.4.12.v20180830

org.eclipse.jetty

jetty-alpn-client

9.4.12.v20180830

org.eclipse.jetty

jetty-alpn-conscrypt-client

9.4.12.v20180830

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Group ID

Artifact ID

Version

org.eclipse.jetty

jetty-alpn-conscrypt-server

9.4.12.v20180830

org.eclipse.jetty

jetty-alpn-java-client

9.4.12.v20180830

org.eclipse.jetty

jetty-alpn-java-server

9.4.12.v20180830

org.eclipse.jetty

jetty-alpn-openjdk8-client

9.4.12.v20180830

org.eclipse.jetty

jetty-alpn-openjdk8-server

9.4.12.v20180830

org.eclipse.jetty

jetty-alpn-server

9.4.12.v20180830

org.eclipse.jetty

jetty-annotations

9.4.12.v20180830

org.eclipse.jetty

jetty-ant

9.4.12.v20180830

org.eclipse.jetty

jetty-client

9.4.12.v20180830

org.eclipse.jetty

jetty-continuation

9.4.12.v20180830

org.eclipse.jetty

jetty-deploy

9.4.12.v20180830

org.eclipse.jetty

jetty-distribution

9.4.12.v20180830

org.eclipse.jetty

jetty-hazelcast

9.4.12.v20180830

org.eclipse.jetty

jetty-home

9.4.12.v20180830

org.eclipse.jetty

jetty-http

9.4.12.v20180830

org.eclipse.jetty

jetty-http-spi

9.4.12.v20180830

org.eclipse.jetty

jetty-infinispan

9.4.12.v20180830

org.eclipse.jetty

jetty-io

9.4.12.v20180830

org.eclipse.jetty

jetty-jaas

9.4.12.v20180830

org.eclipse.jetty

jetty-jaspi

9.4.12.v20180830

org.eclipse.jetty

jetty-jmx

9.4.12.v20180830

org.eclipse.jetty

jetty-jndi

9.4.12.v20180830

org.eclipse.jetty

jetty-nosql

9.4.12.v20180830

org.eclipse.jetty

jetty-plus

9.4.12.v20180830

org.eclipse.jetty

jetty-proxy

9.4.12.v20180830

org.eclipse.jetty

jetty-quickstart

9.4.12.v20180830

org.eclipse.jetty

jetty-reactive-httpclient

1.0.2

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Group ID

Artifact ID

Version

org.eclipse.jetty

jetty-rewrite

9.4.12.v20180830

org.eclipse.jetty

jetty-security

9.4.12.v20180830

org.eclipse.jetty

jetty-server

9.4.12.v20180830

org.eclipse.jetty

jetty-servlet

9.4.12.v20180830

org.eclipse.jetty

jetty-servlets

9.4.12.v20180830

org.eclipse.jetty

jetty-spring

9.4.12.v20180830

org.eclipse.jetty

jetty-unixsocket

9.4.12.v20180830

org.eclipse.jetty

jetty-util

9.4.12.v20180830

org.eclipse.jetty

jetty-util-ajax

9.4.12.v20180830

org.eclipse.jetty

jetty-webapp

9.4.12.v20180830

org.eclipse.jetty

jetty-xml

9.4.12.v20180830

org.eclipse.jetty.cdi

cdi-core

9.4.12.v20180830

org.eclipse.jetty.cdi

cdi-servlet

9.4.12.v20180830

org.eclipse.jetty.fcgi

fcgi-client

9.4.12.v20180830

org.eclipse.jetty.fcgi

fcgi-server

9.4.12.v20180830

org.eclipse.jetty.gcloud

jetty-gcloud-session-manager

9.4.12.v20180830

org.eclipse.jetty.http2

http2-client

9.4.12.v20180830

org.eclipse.jetty.http2

http2-common

9.4.12.v20180830

org.eclipse.jetty.http2

http2-hpack

9.4.12.v20180830

org.eclipse.jetty.http2

http2-http-client-transport

9.4.12.v20180830

org.eclipse.jetty.http2

http2-server

9.4.12.v20180830

org.eclipse.jetty.memcached

jetty-memcached-sessions

9.4.12.v20180830

org.eclipse.jetty.orbit

javax.servlet.jsp

2.2.0.v201112011158

org.eclipse.jetty.osgi

jetty-httpservice

9.4.12.v20180830

org.eclipse.jetty.osgi

jetty-osgi-boot

9.4.12.v20180830

org.eclipse.jetty.osgi

jetty-osgi-boot-jsp

9.4.12.v20180830

org.eclipse.jetty.osgi

jetty-osgi-boot-warurl

9.4.12.v20180830

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Group ID

Artifact ID

Version

org.eclipse.jetty.websocket

javax-websocket-client-impl

9.4.12.v20180830

org.eclipse.jetty.websocket

javax-websocket-server-impl

9.4.12.v20180830

org.eclipse.jetty.websocket

websocket-api

9.4.12.v20180830

org.eclipse.jetty.websocket

websocket-client

9.4.12.v20180830

org.eclipse.jetty.websocket

websocket-common

9.4.12.v20180830

org.eclipse.jetty.websocket

websocket-server

9.4.12.v20180830

org.eclipse.jetty.websocket

websocket-servlet

9.4.12.v20180830

org.ehcache

ehcache

3.6.2

org.ehcache

ehcache-clustered

3.6.2

org.ehcache

ehcache-transactions

3.6.2

org.elasticsearch

elasticsearch

6.4.3

org.elasticsearch.client

elasticsearch-rest-client

6.4.3

org.elasticsearch.client

elasticsearch-rest-high-level-client

6.4.3

org.elasticsearch.client

transport

6.4.3

org.elasticsearch.distribution.integ-test-zip

elasticsearch

6.4.3

org.elasticsearch.plugin

transport-netty4-client

6.4.3

org.firebirdsql.jdbc

jaybird-jdk17

3.0.5

org.firebirdsql.jdbc

jaybird-jdk18

3.0.5

org.flywaydb

flyway-core

5.2.3

org.freemarker

freemarker

2.3.28

org.glassfish

javax.el

3.0.0

org.glassfish.jaxb

jaxb-runtime

2.3.1

org.glassfish.jersey.bundles

jaxrs-ri

2.27

org.glassfish.jersey.connectors

jersey-apache-connector

2.27

org.glassfish.jersey.connectors

jersey-grizzly-connector

2.27

org.glassfish.jersey.connectors

jersey-jdk-connector

2.27

org.glassfish.jersey.connectors

jersey-jetty-connector

2.27

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Group ID

Artifact ID

Version

org.glassfish.jersey.connectors

jersey-netty-connector

2.27

org.glassfish.jersey.containers

jersey-container-grizzly2-http

2.27

org.glassfish.jersey.containers

jersey-container-grizzly2-servlet

2.27

org.glassfish.jersey.containers

jersey-container-jdk-http

2.27

org.glassfish.jersey.containers

jersey-container-jetty-http

2.27

org.glassfish.jersey.containers

jersey-container-jetty-servlet

2.27

org.glassfish.jersey.containers

jersey-container-netty-http

2.27

org.glassfish.jersey.containers

jersey-container-servlet

2.27

org.glassfish.jersey.containers

jersey-container-servlet-core

2.27

org.glassfish.jersey.containers

jersey-container-simple-http

2.27

org.glassfish.jersey.containers.glassfish

jersey-gf-ejb

2.27

org.glassfish.jersey.core

jersey-client

2.27

org.glassfish.jersey.core

jersey-common

2.27

org.glassfish.jersey.core

jersey-server

2.27

org.glassfish.jersey.ext

jersey-bean-validation

2.27

org.glassfish.jersey.ext

jersey-declarative-linking

2.27

org.glassfish.jersey.ext

jersey-entity-filtering

2.27

org.glassfish.jersey.ext

jersey-metainf-services

2.27

org.glassfish.jersey.ext

jersey-mvc

2.27

org.glassfish.jersey.ext

jersey-mvc-bean-validation

2.27

org.glassfish.jersey.ext

jersey-mvc-freemarker

2.27

org.glassfish.jersey.ext

jersey-mvc-jsp

2.27

org.glassfish.jersey.ext

jersey-mvc-mustache

2.27

org.glassfish.jersey.ext

jersey-proxy-client

2.27

org.glassfish.jersey.ext

jersey-servlet-portability

2.27

org.glassfish.jersey.ext

jersey-spring4

2.27

org.glassfish.jersey.ext

jersey-wadl-doclet

2.27

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Group ID

Artifact ID

Version

org.glassfish.jersey.ext.cdi

jersey-cdi1x

2.27

org.glassfish.jersey.ext.cdi

jersey-cdi1x-ban-custom-hk2-binding

2.27

org.glassfish.jersey.ext.cdi

jersey-cdi1x-servlet

2.27

org.glassfish.jersey.ext.cdi

jersey-cdi1x-transaction

2.27

org.glassfish.jersey.ext.cdi

jersey-cdi1x-validation

2.27

org.glassfish.jersey.ext.cdi

jersey-weld2-se

2.27

org.glassfish.jersey.ext.rx

jersey-rx-client-guava

2.27

org.glassfish.jersey.ext.rx

jersey-rx-client-rxjava

2.27

org.glassfish.jersey.ext.rx

jersey-rx-client-rxjava2

2.27

org.glassfish.jersey.inject

jersey-cdi2-se

2.27

org.glassfish.jersey.inject

jersey-hk2

2.27

org.glassfish.jersey.media

jersey-media-jaxb

2.27

org.glassfish.jersey.media

jersey-media-json-binding

2.27

org.glassfish.jersey.media

jersey-media-json-jackson

2.27

org.glassfish.jersey.media

jersey-media-json-jackson1

2.27

org.glassfish.jersey.media

jersey-media-json-jettison

2.27

org.glassfish.jersey.media

jersey-media-json-processing

2.27

org.glassfish.jersey.media

jersey-media-kryo

2.27

org.glassfish.jersey.media

jersey-media-moxy

2.27

org.glassfish.jersey.media

jersey-media-multipart

2.27

org.glassfish.jersey.media

jersey-media-sse

2.27

org.glassfish.jersey.security

oauth1-client

2.27

org.glassfish.jersey.security

oauth1-server

2.27

org.glassfish.jersey.security

oauth1-signature

2.27

org.glassfish.jersey.security

oauth2-client

2.27

org.glassfish.jersey.test-framework

jersey-test-framework-core

2.27

org.glassfish.jersey.test-framework

jersey-test-framework-util

2.27

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Group ID

Artifact ID

Version

org.glassfish.jersey.test-framework.providers

jersey-test-framework-provider-bundle

2.27

org.glassfish.jersey.test-framework.providers

jersey-test-framework-provider-external

2.27

org.glassfish.jersey.test-framework.providers

jersey-test-framework-provider-grizzly2

2.27

org.glassfish.jersey.test-framework.providers

jersey-test-framework-provider-inmemory

2.27

org.glassfish.jersey.test-framework.providers

jersey-test-framework-provider-jdk-http

2.27

org.glassfish.jersey.test-framework.providers

jersey-test-framework-provider-jetty

2.27

org.glassfish.jersey.test-framework.providers

jersey-test-framework-provider-simple

2.27

org.hamcrest

hamcrest-core

1.3

org.hamcrest

hamcrest-library

1.3

org.hibernate

hibernate-c3p0

5.3.7.Final

org.hibernate

hibernate-core

5.3.7.Final

org.hibernate

hibernate-ehcache

5.3.7.Final

org.hibernate

hibernate-entitymanager

5.3.7.Final

org.hibernate

hibernate-envers

5.3.7.Final

org.hibernate

hibernate-hikaricp

5.3.7.Final

org.hibernate

hibernate-java8

5.3.7.Final

org.hibernate

hibernate-jcache

5.3.7.Final

org.hibernate

hibernate-jpamodelgen

5.3.7.Final

org.hibernate

hibernate-proxool

5.3.7.Final

org.hibernate

hibernate-spatial

5.3.7.Final

org.hibernate

hibernate-testing

5.3.7.Final

org.hibernate.validator

hibernate-validator

6.0.13.Final

org.hibernate.validator

hibernate-validator-annotation-processor

6.0.13.Final

org.hsqldb

hsqldb

2.4.1

org.infinispan

infinispan-cachestore-jdbc

9.4.3.Final

org.infinispan

infinispan-cachestore-jpa

9.4.3.Final

org.infinispan

infinispan-cachestore-leveldb

9.4.3.Final

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Group ID

Artifact ID

Version

org.infinispan

infinispan-cachestore-remote

9.4.3.Final

org.infinispan

infinispan-cachestore-rest

9.4.3.Final

org.infinispan

infinispan-cachestore-rocksdb

9.4.3.Final

org.infinispan

infinispan-cdi-common

9.4.3.Final

org.infinispan

infinispan-cdi-embedded

9.4.3.Final

org.infinispan

infinispan-cdi-remote

9.4.3.Final

org.infinispan

infinispan-client-hotrod

9.4.3.Final

org.infinispan

infinispan-cloud

9.4.3.Final

org.infinispan

infinispan-clustered-counter

9.4.3.Final

org.infinispan

infinispan-clustered-lock

9.4.3.Final

org.infinispan

infinispan-commons

9.4.3.Final

org.infinispan

infinispan-core

9.4.3.Final

org.infinispan

infinispan-directory-provider

9.4.3.Final

org.infinispan

infinispan-hibernate-cache-v53

9.4.3.Final

org.infinispan

infinispan-jcache

9.4.3.Final

org.infinispan

infinispan-jcache-commons

9.4.3.Final

org.infinispan

infinispan-jcache-remote

9.4.3.Final

org.infinispan

infinispan-lucene-directory

9.4.3.Final

org.infinispan

infinispan-objectfilter

9.4.3.Final

org.infinispan

infinispan-osgi

9.4.3.Final

org.infinispan

infinispan-persistence-cli

9.4.3.Final

org.infinispan

infinispan-persistence-soft-index

9.4.3.Final

org.infinispan

infinispan-query

9.4.3.Final

org.infinispan

infinispan-query-dsl

9.4.3.Final

org.infinispan

infinispan-remote-query-client

9.4.3.Final

org.infinispan

infinispan-remote-query-server

9.4.3.Final

org.infinispan

infinispan-scripting

9.4.3.Final

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Group ID

Artifact ID

Version

org.infinispan

infinispan-server-core

9.4.3.Final

org.infinispan

infinispan-server-hotrod

9.4.3.Final

org.infinispan

infinispan-server-memcached

9.4.3.Final

org.infinispan

infinispan-server-router

9.4.3.Final

org.infinispan

infinispan-spring4-common

9.4.3.Final

org.infinispan

infinispan-spring4-embedded

9.4.3.Final

org.infinispan

infinispan-spring4-remote

9.4.3.Final

org.infinispan

infinispan-tasks

9.4.3.Final

org.infinispan

infinispan-tasks-api

9.4.3.Final

org.infinispan

infinispan-tools

9.4.3.Final

org.infinispan

infinispan-tree

9.4.3.Final

org.influxdb

influxdb-java

2.14

org.jboss

jboss-transaction-spi

7.6.0.Final

org.jboss.logging

jboss-logging

3.3.2.Final

org.jdom

jdom2

2.0.6

org.jetbrains.kotlin

kotlin-reflect

1.2.71

org.jetbrains.kotlin

kotlin-runtime

1.2.71

org.jetbrains.kotlin

kotlin-stdlib

1.2.71

org.jetbrains.kotlin

kotlin-stdlib-jdk7

1.2.71

org.jetbrains.kotlin

kotlin-stdlib-jdk8

1.2.71

org.jetbrains.kotlin

kotlin-stdlib-jre7

1.2.71

org.jetbrains.kotlin

kotlin-stdlib-jre8

1.2.71

org.jolokia

jolokia-core

1.6.0

org.jooq

jooq

3.11.7

org.jooq

jooq-codegen

3.11.7

org.jooq

jooq-meta

3.11.7

org.junit.jupiter

junit-jupiter-api

5.3.2

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Group ID

Artifact ID

Version

org.junit.jupiter

junit-jupiter-engine

5.3.2

org.junit.jupiter

junit-jupiter-migrationsupport

5.3.2

org.junit.jupiter

junit-jupiter-params

5.3.2

org.junit.platform

junit-platform-commons

1.3.2

org.junit.platform

junit-platform-console

1.3.2

org.junit.platform

junit-platform-engine

1.3.2

org.junit.platform

junit-platform-launcher

1.3.2

org.junit.platform

junit-platform-runner

1.3.2

org.junit.platform

junit-platform-suite-api

1.3.2

org.junit.platform

junit-platform-surefire-provider

1.3.2

org.junit.vintage

junit-vintage-engine

5.3.2

org.jvnet.mimepull

mimepull

1.9.10

org.liquibase

liquibase-core

3.6.2

org.mariadb.jdbc

mariadb-java-client

2.3.0

org.messaginghub

pooled-jms

1.0.3

org.mockito

mockito-core

2.23.4

org.mockito

mockito-inline

2.23.4

org.mockito

mockito-junit-jupiter

2.23.4

org.mongodb

bson

3.8.2

org.mongodb

mongodb-driver

3.8.2

org.mongodb

mongodb-driver-async

3.8.2

org.mongodb

mongodb-driver-core

3.8.2

org.mongodb

mongodb-driver-reactivestreams

1.9.2

org.mongodb

mongo-java-driver

3.8.2

org.mortbay.jasper

apache-el

8.5.33.1

org.neo4j

neo4j-ogm-api

3.1.5

org.neo4j

neo4j-ogm-bolt-driver

3.1.5

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Group ID

Artifact ID

Version

org.neo4j

neo4j-ogm-core

3.1.5

org.neo4j

neo4j-ogm-embedded-driver

3.1.5

org.neo4j

neo4j-ogm-http-driver

3.1.5

org.postgresql

postgresql

42.2.5

org.projectlombok

lombok

1.18.4

org.quartz-scheduler

quartz

2.3.0

org.quartz-scheduler

quartz-jobs

2.3.0

org.reactivestreams

reactive-streams

1.0.2

org.seleniumhq.selenium

htmlunit-driver

2.33.0

org.seleniumhq.selenium

selenium-api

3.14.0

org.seleniumhq.selenium

selenium-chrome-driver

3.14.0

org.seleniumhq.selenium

selenium-edge-driver

3.14.0

org.seleniumhq.selenium

selenium-firefox-driver

3.14.0

org.seleniumhq.selenium

selenium-ie-driver

3.14.0

org.seleniumhq.selenium

selenium-java

3.14.0

org.seleniumhq.selenium

selenium-opera-driver

3.14.0

org.seleniumhq.selenium

selenium-remote-driver

3.14.0

org.seleniumhq.selenium

selenium-safari-driver

3.14.0

org.seleniumhq.selenium

selenium-support

3.14.0

org.skyscreamer

jsonassert

1.5.0

org.slf4j

jcl-over-slf4j

1.7.25

org.slf4j

jul-to-slf4j

1.7.25

org.slf4j

log4j-over-slf4j

1.7.25

org.slf4j

slf4j-api

1.7.25

org.slf4j

slf4j-ext

1.7.25

org.slf4j

slf4j-jcl

1.7.25

org.slf4j

slf4j-jdk14

1.7.25

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Group ID

Artifact ID

Version

org.slf4j

slf4j-log4j12

1.7.25

org.slf4j

slf4j-nop

1.7.25

org.slf4j

slf4j-simple

1.7.25

org.springframework

spring-aop

5.1.3.RELEASE

org.springframework

spring-aspects

5.1.3.RELEASE

org.springframework

spring-beans

5.1.3.RELEASE

org.springframework

spring-context

5.1.3.RELEASE

org.springframework

spring-context-indexer

5.1.3.RELEASE

org.springframework

spring-context-support

5.1.3.RELEASE

org.springframework

spring-core

5.1.3.RELEASE

org.springframework

spring-expression

5.1.3.RELEASE

org.springframework

spring-instrument

5.1.3.RELEASE

org.springframework

spring-jcl

5.1.3.RELEASE

org.springframework

spring-jdbc

5.1.3.RELEASE

org.springframework

spring-jms

5.1.3.RELEASE

org.springframework

spring-messaging

5.1.3.RELEASE

org.springframework

spring-orm

5.1.3.RELEASE

org.springframework

spring-oxm

5.1.3.RELEASE

org.springframework

spring-test

5.1.3.RELEASE

org.springframework

spring-tx

5.1.3.RELEASE

org.springframework

spring-web

5.1.3.RELEASE

org.springframework

spring-webflux

5.1.3.RELEASE

org.springframework

spring-webmvc

5.1.3.RELEASE

org.springframework

spring-websocket

5.1.3.RELEASE

org.springframework.amqp

spring-amqp

2.1.2.RELEASE

org.springframework.amqp

spring-rabbit

2.1.2.RELEASE

org.springframework.amqp

spring-rabbit-junit

2.1.2.RELEASE

https://docs.spring.io/spring-boot/docs/2.1.2.BUILD-SNAPSHOT/reference/htmlsingle/

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Group ID

Artifact ID

Version

org.springframework.amqp

spring-rabbit-test

2.1.2.RELEASE

org.springframework.batch

spring-batch-core

4.1.0.RELEASE

org.springframework.batch

spring-batch-infrastructure

4.1.0.RELEASE

org.springframework.batch

spring-batch-integration

4.1.0.RELEASE

org.springframework.batch

spring-batch-test

4.1.0.RELEASE

org.springframework.boot

spring-boot

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-actuator

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-actuator-autoconfigure

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-autoconfigure

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-autoconfigure-processor

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-configuration-metadata

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-configuration-processor

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-devtools

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-loader

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-loader-tools

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-properties-migrator

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-activemq

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-actuator

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-amqp

2.1.2.BUILDSNAPSHOT

https://docs.spring.io/spring-boot/docs/2.1.2.BUILD-SNAPSHOT/reference/htmlsingle/

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Group ID

Artifact ID

Version

org.springframework.boot

spring-boot-starter-aop

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-artemis

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-batch

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-cache

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-cloud-connectors

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-data-cassandra

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-data-cassandra-reactive

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-data-couchbase

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-data-couchbase-reactive

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-data-elasticsearch

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-data-jdbc

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-data-jpa

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-data-ldap

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-data-mongodb

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-data-mongodb-reactive

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-data-neo4j

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-data-redis

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-data-redis-reactive

2.1.2.BUILDSNAPSHOT

https://docs.spring.io/spring-boot/docs/2.1.2.BUILD-SNAPSHOT/reference/htmlsingle/

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Group ID

Artifact ID

Version

org.springframework.boot

spring-boot-starter-data-rest

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-data-solr

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-freemarker

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-groovy-templates

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-hateoas

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-integration

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-jdbc

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-jersey

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-jetty

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-jooq

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-json

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-jta-atomikos

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-jta-bitronix

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-log4j2

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-logging

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-mail

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-mustache

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-oauth2-client

2.1.2.BUILDSNAPSHOT

https://docs.spring.io/spring-boot/docs/2.1.2.BUILD-SNAPSHOT/reference/htmlsingle/

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Group ID

Artifact ID

Version

org.springframework.boot

spring-boot-starter-oauth2-resource-server

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-quartz

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-reactor-netty

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-security

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-test

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-thymeleaf

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-tomcat

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-undertow

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-validation

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-web

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-webflux

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-web-services

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-starter-websocket

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-test

2.1.2.BUILDSNAPSHOT

org.springframework.boot

spring-boot-test-autoconfigure

2.1.2.BUILDSNAPSHOT

org.springframework.cloud

spring-cloud-cloudfoundry-connector

2.0.4.RELEASE

org.springframework.cloud

spring-cloud-connectors-core

2.0.4.RELEASE

org.springframework.cloud

spring-cloud-heroku-connector

2.0.4.RELEASE

org.springframework.cloud

spring-cloud-localconfig-connector

2.0.4.RELEASE

org.springframework.cloud

spring-cloud-spring-service-connector

2.0.4.RELEASE

https://docs.spring.io/spring-boot/docs/2.1.2.BUILD-SNAPSHOT/reference/htmlsingle/

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Group ID

Artifact ID

Version

org.springframework.data

spring-data-cassandra

2.1.3.RELEASE

org.springframework.data

spring-data-commons

2.1.3.RELEASE

org.springframework.data

spring-data-couchbase

3.1.3.RELEASE

org.springframework.data

spring-data-elasticsearch

3.1.3.RELEASE

org.springframework.data

spring-data-envers

2.1.3.RELEASE

org.springframework.data

spring-data-gemfire

2.1.3.RELEASE

org.springframework.data

spring-data-geode

2.1.3.RELEASE

org.springframework.data

spring-data-jdbc

1.0.3.RELEASE

org.springframework.data

spring-data-jpa

2.1.3.RELEASE

org.springframework.data

spring-data-keyvalue

2.1.3.RELEASE

org.springframework.data

spring-data-ldap

2.1.3.RELEASE

org.springframework.data

spring-data-mongodb

2.1.3.RELEASE

org.springframework.data

spring-data-mongodb-cross-store

2.1.3.RELEASE

org.springframework.data

spring-data-neo4j

5.1.3.RELEASE

org.springframework.data

spring-data-redis

2.1.3.RELEASE

org.springframework.data

spring-data-rest-core

3.1.3.RELEASE

org.springframework.data

spring-data-rest-hal-browser

3.1.3.RELEASE

org.springframework.data

spring-data-rest-webmvc

3.1.3.RELEASE

org.springframework.data

spring-data-solr

4.0.3.RELEASE

org.springframework.hateoas

spring-hateoas

0.25.0.RELEASE

org.springframework.integration

spring-integration-amqp

5.1.1.RELEASE

org.springframework.integration

spring-integration-core

5.1.1.RELEASE

org.springframework.integration

spring-integration-event

5.1.1.RELEASE

org.springframework.integration

spring-integration-feed

5.1.1.RELEASE

org.springframework.integration

spring-integration-file

5.1.1.RELEASE

org.springframework.integration

spring-integration-ftp

5.1.1.RELEASE

org.springframework.integration

spring-integration-gemfire

5.1.1.RELEASE

https://docs.spring.io/spring-boot/docs/2.1.2.BUILD-SNAPSHOT/reference/htmlsingle/

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Group ID

Artifact ID

Version

org.springframework.integration

spring-integration-groovy

5.1.1.RELEASE

org.springframework.integration

spring-integration-http

5.1.1.RELEASE

org.springframework.integration

spring-integration-ip

5.1.1.RELEASE

org.springframework.integration

spring-integration-jdbc

5.1.1.RELEASE

org.springframework.integration

spring-integration-jms

5.1.1.RELEASE

org.springframework.integration

spring-integration-jmx

5.1.1.RELEASE

org.springframework.integration

spring-integration-jpa

5.1.1.RELEASE

org.springframework.integration

spring-integration-mail

5.1.1.RELEASE

org.springframework.integration

spring-integration-mongodb

5.1.1.RELEASE

org.springframework.integration

spring-integration-mqtt

5.1.1.RELEASE

org.springframework.integration

spring-integration-redis

5.1.1.RELEASE

org.springframework.integration

spring-integration-rmi

5.1.1.RELEASE

org.springframework.integration

spring-integration-scripting

5.1.1.RELEASE

org.springframework.integration

spring-integration-security

5.1.1.RELEASE

org.springframework.integration

spring-integration-sftp

5.1.1.RELEASE

org.springframework.integration

spring-integration-stomp

5.1.1.RELEASE

org.springframework.integration

spring-integration-stream

5.1.1.RELEASE

org.springframework.integration

spring-integration-syslog

5.1.1.RELEASE

org.springframework.integration

spring-integration-test

5.1.1.RELEASE

org.springframework.integration

spring-integration-test-support

5.1.1.RELEASE

org.springframework.integration

spring-integration-webflux

5.1.1.RELEASE

org.springframework.integration

spring-integration-websocket

5.1.1.RELEASE

org.springframework.integration

spring-integration-ws

5.1.1.RELEASE

org.springframework.integration

spring-integration-xml

5.1.1.RELEASE

org.springframework.integration

spring-integration-xmpp

5.1.1.RELEASE

org.springframework.integration

spring-integration-zookeeper

5.1.1.RELEASE

org.springframework.kafka

spring-kafka

2.2.2.RELEASE

https://docs.spring.io/spring-boot/docs/2.1.2.BUILD-SNAPSHOT/reference/htmlsingle/

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Group ID

Artifact ID

Version

org.springframework.kafka

spring-kafka-test

2.2.2.RELEASE

org.springframework.ldap

spring-ldap-core

2.3.2.RELEASE

org.springframework.ldap

spring-ldap-core-tiger

2.3.2.RELEASE

org.springframework.ldap

spring-ldap-ldif-batch

2.3.2.RELEASE

org.springframework.ldap

spring-ldap-ldif-core

2.3.2.RELEASE

org.springframework.ldap

spring-ldap-odm

2.3.2.RELEASE

org.springframework.ldap

spring-ldap-test

2.3.2.RELEASE

org.springframework.plugin

spring-plugin-core

1.2.0.RELEASE

org.springframework.plugin

spring-plugin-metadata

1.2.0.RELEASE

org.springframework.restdocs

spring-restdocs-asciidoctor

2.0.2.RELEASE

org.springframework.restdocs

spring-restdocs-core

2.0.2.RELEASE

org.springframework.restdocs

spring-restdocs-mockmvc

2.0.2.RELEASE

org.springframework.restdocs

spring-restdocs-restassured

2.0.2.RELEASE

org.springframework.restdocs

spring-restdocs-webtestclient

2.0.2.RELEASE

org.springframework.retry

spring-retry

1.2.2.RELEASE

org.springframework.security

spring-security-acl

5.1.2.RELEASE

org.springframework.security

spring-security-aspects

5.1.2.RELEASE

org.springframework.security

spring-security-cas

5.1.2.RELEASE

org.springframework.security

spring-security-config

5.1.2.RELEASE

org.springframework.security

spring-security-core

5.1.2.RELEASE

org.springframework.security

spring-security-crypto

5.1.2.RELEASE

org.springframework.security

spring-security-data

5.1.2.RELEASE

org.springframework.security

spring-security-ldap

5.1.2.RELEASE

org.springframework.security

spring-security-messaging

5.1.2.RELEASE

org.springframework.security

spring-security-oauth2-client

5.1.2.RELEASE

org.springframework.security

spring-security-oauth2-core

5.1.2.RELEASE

org.springframework.security

spring-security-oauth2-jose

5.1.2.RELEASE

https://docs.spring.io/spring-boot/docs/2.1.2.BUILD-SNAPSHOT/reference/htmlsingle/

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Group ID

Artifact ID

Version

org.springframework.security

spring-security-oauth2-resource-server

5.1.2.RELEASE

org.springframework.security

spring-security-openid

5.1.2.RELEASE

org.springframework.security

spring-security-remoting

5.1.2.RELEASE

org.springframework.security

spring-security-taglibs

5.1.2.RELEASE

org.springframework.security

spring-security-test

5.1.2.RELEASE

org.springframework.security

spring-security-web

5.1.2.RELEASE

org.springframework.session

spring-session-core

2.1.2.RELEASE

org.springframework.session

spring-session-data-gemfire

2.1.1.RELEASE

org.springframework.session

spring-session-data-geode

2.1.1.RELEASE

org.springframework.session

spring-session-data-mongodb

2.1.1.RELEASE

org.springframework.session

spring-session-data-redis

2.1.2.RELEASE

org.springframework.session

spring-session-hazelcast

2.1.2.RELEASE

org.springframework.session

spring-session-jdbc

2.1.2.RELEASE

org.springframework.ws

spring-ws-core

3.0.4.RELEASE

org.springframework.ws

spring-ws-security

3.0.4.RELEASE

org.springframework.ws

spring-ws-support

3.0.4.RELEASE

org.springframework.ws

spring-ws-test

3.0.4.RELEASE

org.springframework.ws

spring-xml

3.0.4.RELEASE

org.synchronoss.cloud

nio-multipart-parser

1.1.0

org.thymeleaf

thymeleaf

3.0.11.RELEASE

org.thymeleaf

thymeleaf-spring5

3.0.11.RELEASE

org.thymeleaf.extras

thymeleaf-extras-java8time

3.0.2.RELEASE

org.thymeleaf.extras

thymeleaf-extras-springsecurity5

3.0.4.RELEASE

org.webjars

hal-browser

3325375

org.webjars

webjars-locator-core

0.35

org.xerial

sqlite-jdbc

3.25.2

org.xmlunit

xmlunit-core

2.6.2

https://docs.spring.io/spring-boot/docs/2.1.2.BUILD-SNAPSHOT/reference/htmlsingle/

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Group ID

Artifact ID

Version

org.xmlunit

xmlunit-legacy

2.6.2

org.xmlunit

xmlunit-matchers

2.6.2

org.yaml

snakeyaml

1.23

redis.clients

jedis

2.9.0

wsdl4j

wsdl4j

1.6.3

xml-apis

xml-apis

1.4.01

https://docs.spring.io/spring-boot/docs/2.1.2.BUILD-SNAPSHOT/reference/htmlsingle/

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