Dozer Reference Manual User Guide

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......................................................................................................................................

Dozer
v.5.5.1
User's Guide

......................................................................................................................................
Franz Garsombke, Matt Tierney, Dmitry
Buzdin

2014-04-22

Table of Contents

i

Table of Contents

.......................................................................................................................................
1. Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i
2. Why Map? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
3. Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
4. Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
5. Mappings via Annotations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6. Mappings via API . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7. Mappings via XML . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
7..1. Mapping Two Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

14

7..2. Basic Property Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

15

7..3. String To Date Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

17

7..4. Enum Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

19

7..5. Collection Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

21

7..6. Map Backed Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

27

7..7. Index Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

32

7..8. Deep Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

33

7..9. Excluding Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

36

7..10. One-Way Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

39

7..11. Context Based Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

41

7..12. Global Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

43

7..13. Custom Converters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

46

7..14. Custom Bean Factories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

55

7..15. Custom Create Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

58

7..16. Custom Get/Set Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

59

7..17. Copy By Ref Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

61

7..18. Inheritance Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

63

7..19. Dozer Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

67

7..20. Expression Language . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

69

Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

70

8..1. Logging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

72

8..2. Proxy Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

73

8.

9.
10.
11.
12.
13.
14.

Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
JMX Integration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Spring Integration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
JAXB and XMLBeans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Metadata Query Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FAQ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

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75
77
79
81
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Table of Contents

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

ii

1 Why Map?

1

1 Why Map?

.......................................................................................................................................
1.1 Why Map?
A mapping framework is useful in a layered architecture where you are creating layers of abstraction
by encapsulating changes to particular data objects vs. propagating these objects to other layers (i.e.
external service data objects, domain objects, data transfer objects, internal service data objects). A
mapping framework is ideal for using within Mapper type classes that are responsible for mapping
data from one data object to another.
For distributed systems, a side effect is the passing of domain objects between different systems.
Typically, you won't want internal domain objects exposed externally and won't allow for external
domain objects to bleed into your system.
Mapping between data objects has been traditionally addressed by hand coding value object
assemblers (or converters) that copy data between the objects. Most programmers will develop some
sort of custom mapping framework and spend countless hours and thousands of lines of code mapping
to and from their different data object.
A generic mapping framework solves these problems. Dozer is an open source mapping framework
that is robust, generic, flexible, reusable, and configurable.
Data object mapping is an important part of layered service oriented architectures. Pick and choose
the layers you use mapping carefully. Do not go overboard as there is maintenance and performance
costs associated with mapping data objects between layers.
1.1.1 Parallel Object Hierarchies

There could be different reasons of why application should support parallel object hierarhchies. To
name a few:
• Integration with External Code
• Serialization Requirements
• Framework Integration
• Separation of Architectural Layers
In some cases it is efficient to guard your code base from frequently changing object hierarchy, which
you do not control directly. In this case Dozer serves as a bridge between application and external
objects. As mapping is performed in reflective manner not all changes break your API. For example if
object changes from Number to String the code will keep working as this is resolved automatically.
Some frameworks impose Serialization constraints, which does not allow sending any Java objects
through the wire. One of the popular examples is Google Web Toolkit (GWT) framework, which
restricts developer to sending only objects compiled to JavaScript and marked as Serializable. Dozer
helps to convert Rich Domain Model to Presentation Model, which satisfies GWT serialization
requirements.
Dozer integrates nicely with frameworks such as Apache XmlBeans and JAXB implementations.
With help of provided factory classes, conversion between domain model and Xml objects is defined
in the same way as plain object to object mappings.
In complex enterprise application it is often valuable to separate design to several architectural layers.
Each of them would reside on its own abstraction level. A typical simplified example would be
presentation, domain and persistence layers. Each of this layers could have own set of Java Beans
representing data relevant for this layer. It is not necessary that all data will travel to the upper levels
of architecture. For example the same domain object could have different mappings dependant of the
presentation layer requirements.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

2 Getting Started

2 Getting Started

2

.......................................................................................................................................
2.1 Getting Started
2.1.1 Downloading the Distribution

• Download Dozer and extract the archive.
• Add dozer.jar to your classpath.
• Add required thirdparty runtime jars to your classpath.
If you are using Maven, simply copy-paste this dependency to your project.

net.sf.dozer
dozer
5.4.0


Apache Ivy users can copy-paste the following line instead.


2.1.2 1st Mapping

For your first mapping lets assume that the two data objects share all common attribute names.

Mapper mapper = new DozerBeanMapper();
DestinationObject destObject =
mapper.map(sourceObject, DestinationObject.class);

After performing the Dozer mapping, the result will be a new instance of the destination object that
contains values for all fields that have the same field name as the source object. If any of the mapped
attributes are of different data types, the Dozer mapping engine will automatically perform data type
conversion. At this point you have completed your first Dozer mapping. Later sections will go over
how to specify custom mappings via custom xml files.
IMPORTANT: For real-world applications it is NOT recommended to create a new instance of
the Mapper each time you map objects. Typically a system will only have one DozerBeanMapper
instance per VM. If you are not using an IOC framework where you can define the Mapper Instance
as singleton="true". If needed, a DozerBeanMapperSingletonWrapper convenience class has been
provided in the Dozer jar.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

2 Getting Started

3

2.1.3 Specifying Custom Mappings via XML

If the two different types of data objects that you are mapping contain any fields that don't share a
common property name, you will need to add a class mapping entry to your custom mapping xml file.
These mappings xml files are used at runtime by the Dozer mapping engine.
Dozer automatically performs any type conversion when copying the source field data to the
destination field. The Dozer mapping engine is bi-directional, so if you wanted to map the destination
object to the source object, you do not need to add another class mapping to the xml file.
IMPORTANT: Fields that are of the same name do not need to be specified in the mapping xml
file. Dozer automatically maps all fields with the same property name from the source object into the
destination object.


yourpackage.yourSourceClassName
yourpackage.yourDestinationClassName

yourSourceFieldName
yourDestinationFieldName



The complete Dozer mapping xml file would look like the following. The Custom Mappings section
contains more information on mapping options that are available to you for more complex use cases.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

2 Getting Started




true
MM/dd/yyyy HH:mm
true


yourpackage.yourSourceClassName
yourpackage.yourDestinationClassName

yourSourceFieldName
yourDestinationFieldName


other custom class mappings would go here.......


2.1.4 Dozer and Dependency Injection Frameworks

Dozer is not dependant of any existing Dependency Injection framework (DI). However the general
aim is to support the most typical use cases with ready-to-use Wrappers. Check Spring Integration
manual for option of initializing Dozer in context of Spring DI framework.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

4

3 Usage

3 Usage

5

.......................................................................................................................................
3.1 General Usage
Requirements for running Dozer:
• Dozer uses SLF4J for logging purposes.
• Dozer needs a few third-party runtime jars.
• All of the required runtime jars are in the {dozer.home}/repository directory and need to be in
your Classpath
• The dozer.jar file in the {dozer.home}/dist directory needs to be in your Classpath
3.1.1 Dozer Bean Mapper

Before we go over setting up custom xml bean mappings, let us look at a simple example of using
Dozer. The Dozer mapping implementation has a method called map which takes a source object
and either a destination object or destination object class type. After mapping the two objects it then
returns the destination object with all of its mapped fields.

Mapper mapper = new DozerBeanMapper();
DestinationObject destObject =
mapper.map(sourceObject, DestinationObject.class);
or
DestinationObject destObject = new DestinationObject();
mapper.map(sourceObject, destObject);

IMPORTANT: For real-world applications it is not recommended that you create a new instance
of the Mapper each time you map objects. Typically a system will only have one DozerBeanMapper
instance per VM. If you are not using an IOC framework where you can define the Mapper as
singleton="true", a DozerBeanMapperSingletonWrapper convenience class has been provided in the
Dozer jar.
Dozer operates in two general modes: implicit and explicit. Implicit mode is activated by default
and tries to resolve mappings for you. It uses simple assumptions that if two objects are passed
for mapping then bean properties with the same names should be mapped. If there are additional
mappings needed, which can not be derived by the naming you should add those either via Xml,
Annotations or API.
Explicit mode assumes that no mappings should be performed or "guessed" until you have specified
those specifically. The amount of coding is higher in explicit mode, but sometimes you would like to
have full control on what is going on during the mappings process and this approach is also used in
many of the productive applications. Implicit/Explicit mapping switch is called "wildcard" in Dozer.
Whenever you encounter that in configuration you know what behavior to expect from now on.
3.1.2 Injecting Custom Mapping Files

The Dozer mapping xml file(s) define any custom mappings that can't be automatically performed
by the Dozer mapping engine. Any custom Dozer mapping files need to be injected into the Mapper

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

3 Usage

6

implementation(org.dozer.DozerBeanMapper). Both setter-based and constructor-based injection are
supported.
Preferably, you will be using an IOC framework such as Spring for these Dozer injection
requirements. Alternatively, the injection of mapping files can be done programmatically. Below is a
programmatic approach to creating a bean mapper. Note that this is NOT the recommended way to
retrieve the bean mapper . Each new instance needs to be initialized and this consumes time as well
as resources. If you are using the mapper this way just wrap it using the singleton pattern.

List myMappingFiles = new ArrayList();
myMappingFiles.add("dozerBeanMapping.xml");
myMappingFiles.add("someOtherDozerBeanMappings.xml");
DozerBeanMapper mapper = new DozerBeanMapper();
mapper.setMappingFiles(myMappingFiles);
DestinationObject destObject =
mapper.map(sourceObject, DestinationObject.class);

IMPORTANT: Mapper instance(s) should be setup as a Singleton regardless of how you choose
to inject the Mapper instance(s). You should configure the Mapper this way so that you do not have
to reload and reinitialize the mapping files for each individual mapping during the lifecycle of your
app. Reinitializing the mapping files for each mapping would be inefficient and unnecessary. The
DozerBeanMapper.java class is thread safe.
3.1.3 Spring Integration

The following is an example how the Mapper bean would be configured via Spring.
Sample spring.xml bean definition...




dozer-global-configuration.xml
dozer-bean-mappings.xml
more-dozer-bean-mappings.xml




3.1.4 Dozer Bean Mapper Singleton Wrapper

There is one way to configure the DozerBeanMapperSingletonWrapper to use your custom mapping
file.
• Using one mapping file: A file called dozerBeanMapping.xml file will be loaded if it is in your
Classpath. You can find a sample of this file in the {dozer.home}/mappings directory.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

3 Usage

The mapping file defines all of the relationships between Java classes and their attributes. The
Custom Mappings section details the custom XML mapping options that are available.
The following example show how to use the DozerBeanMapperSingletonWrapper. Dozer has a
method called map which takes a source object and either a destination object or destination object
class type. After mapping the two objects it then returns the destination object with all of its mapped
fields.
Mapper mapper = DozerBeanMapperSingletonWrapper.getInstance();
DestinationObject destObject =
mapper.map(sourceObject, DestinationObject.class);
or
Mapper mapper = DozerBeanMapperSingletonWrapper.getInstance();
DestinationObject destObject = new DestinationObject();
mapper.map(sourceObject, destObject);

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

7

4 Mappings via Annotations

8

4 Mappings via Annotations

.......................................................................................................................................
4.1 Annotation Mappings
4.1.1 Why Annotations?

One of the downsides of using Dozer for the long time was Xml. Since Dozer started during Xmlhype years more than five years ago that was pretty obvious choice back then. After that Java 5
brought us annotations and new industry accepted style of configuring behaviour are Domain-Specific
Languages. DSL-like support is provided in form of mapping API, but since version 5.3.2 Dozer starts
providing annotations support as well.
The obvious reasons to use annotations is to avoid duplicating field and method names in your
mapping code. The annotation can be put onto the mapped property itself thus reducing the amount of
code. However there are cases when annotations should be avoided or even impossible to use. Some
of them are the following:
• You are mapping classes, which are not under your control, but provided in libraries;
• The mappings are quite complex and require many configurations;
In the first case you could be mapping JAXB generated entities or third-party DTOs and have
no possibility to put annotations. In the second case there is a choice of putting lots of multi-line
annotations or isolating the mapping code with certain duplication of entity names. Overannotated
beans could be problematic to read and understand.
4.1.2 Usage

WARNING: Annotation support in Dozer is experimental and does not cover complex use cases yet.
However it may be useful to implement that simplest mappings you have had to do in Xml or API
before.
The idea is very simple. You put @Mapping annotation either on getter of field directly. If Dozer
finds that it adds a bi-directional mapping. It means that putting annotation once will create mappings
for both conversion types. Type conversions (e.g. String-Long) will be chosen automatically. Global
custom converters are resolved as well. Annotations work only if a conversion is subject to wildcard
rule (active by default). The following example demonstrates annotations in action.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

4 Mappings via Annotations

9

public class SourceBean {
private Long id;
private String name;
@Mapping("binaryData")
private String data;
@Mapping("pk")
public Long getId() {
return this.id;
}
public String getName() {
return this.name;
}
}

public class TargetBean {
private String pk;
private String name;
private String binaryData;
public void setPk(String pk) {
this.pk = pk;
}
public void setName(String name) {
this.name = name;
}
}

Mapping the given beans with Dozer will result in all three fields being mapped. Property "name"
will be mapped by naming convention. Property "id" will be transformed to "pk". Field "data" will be
moved to "binaryData". Do not worry about private modifier; it will be handled automatically.
Currently Dozer offers only one annotation, but the next ones will be added in following releases. As
for now you can mix and match all flavours of mapping types to achieve the desired effect: Xml, API
and Annotations.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

5 Mappings via API

10

5 Mappings via API

.......................................................................................................................................
5.1 API Mappings
Since version 5.3 Dozer offers two ways for specifying explicit mappings. First is Xml-based and has
been there for years. Second is API-based and it is brand new. On the high level both approaches are
functionally equivalent, however there are major differences in using those described further on.
5.1.1 XML Mapping Flaws

XML-based approach is stable and is used in many production projects. However, it imposes several
limitations.
• First, and most important, is that it can not be dynamically generated. All XML mappings should
be present on Dozer start-up and can not be modified afterwards. There are tricky ways, when
you can generate and put mappings to the file system by your own templating engine, but this
approach is not supported by Dozer itself. By generating custom mappings you are able to
automate repetitive chunks of low-level Dozer language.
• Second problem is that you are forced to duplicate all of your Bean class names in Xml
mappings. This leads to lots of typing and copy-paste programming. This can be partly
compensated by use of Expression Language inside Xml, but it is not solving all of the problems.
• Refactoring support is limited as IDE should keep track of class names in Xml files and change
them when you rename or move the referenced class. Auto-completion support is also not
available in all IDEs.
5.1.2 API Mappings

API mappings are intended to solve all of the mentioned problems. To preserve backwards
compatibility API mappings can be combined with existing Xml mappings. In fact some parts of the
configuration (e.g. global configuration block) are only possible to express in Xml format.
To get a feeling of what are these mappings take a look at the following code example.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

5 Mappings via API

11

import static org.dozer.loader.api.FieldsMappingOptions.*;
import static org.dozer.loader.api.TypeMappingOptions.*;
...
BeanMappingBuilder builder = new BeanMappingBuilder() {
protected void configure() {
mapping(Bean.class, Bean.class,
TypeMappingOptions.oneWay(),
mapId("A"),
mapNull(true)
)
.exclude("excluded")
.fields("src", "dest",
copyByReference(),
collectionStrategy(true,
RelationshipType.NON_CUMULATIVE),
hintA(String.class),
hintB(Integer.class),
FieldsMappingOptions.oneWay(),
useMapId("A"),
customConverterId("id")
)
.fields("src", "dest",
customConverter("org.dozer.CustomConverter")
);
}
};

Constructed builder object should be then passed to DozerBeanMapper instance. It is possible to add
multiple Builder classes.

DozerBeanMapper mapper = new DozerBeanMapper();
mapper.addMapping(builder);

Don't forget to make a static import of FieldsMappingOptions and TypeMappingOptions classes.
That's it.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

6 Mappings via XML

12

6 Mappings via XML

.......................................................................................................................................
6.1 Custom Mappings Via Dozer XML Files
This section will cover setting up custom mappings in xml file(s). If the two different types of data
objects that you are mapping contain any fields that don't share a common property name, you will
need to add a class mapping entry to your custom mapping xml file. These mappings xml files are
used at runtime by the Dozer mapping engine.
Dozer automatically performs any type conversion when copying the source field data to the
destination field. The Dozer mapping engine is bi-directional, so if you wanted to map the destination
object to the source object, you do not need to add another class mapping to the xml file.
An example of a mapping file....




org.dozer.vo.TestObject
org.dozer.vo.TestObjectPrime

one
onePrime



org.dozer.vo.TestObjectFoo
org.dozer.vo.TestObjectFooPrime

oneFoo
oneFooPrime




A mappings element has multiple mapping elements, each with class mapping declarations and field
level mappings. The wildcard attribute is set to true by default. This means that it will automatically
try to map every property in the two objects. When the attribute is set to false it will only map
explicitly defined fields.
IMPORTANT: Properties that are of the same name do not need to be specified in the mapping xml
file. Dozer automatically maps all fields with the same property name from the source object into the
destination object.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

6 Mappings via XML

13

6.2 How Custom Mapping Files Are Loaded
Dozer will search the entire classpath looking for the specified file. The generally acceptable way of
distributing your mappings is to bundle them inside your application archive.
Alternatively, you can load files from outside the classpath by prepending "file:" to the resource
name. Ex) "file:c:\somedozermapping.xml"

6.3 Loading Files from Input Stream
Since version 5.4.0 it is possible to load XML mapping files from provided InputStream object.
Check DozerMapper class for the corresponding API calls.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

7 Mapping Two Classes

14

7 Mapping Two Classes

.......................................................................................................................................
7.1 Mapping Classes
An example of mapping two classes is defined below. Note: Explicit xml mapping for 2 classes is
not required if all the field mapping between src and dest object can be performed by matching on
attribute name. Custom xml class mapping is only required when you need to specify any custom field
mappings.



org.dozer.vo.TestObject
org.dozer.vo.TestObjectPrime




These mappings are bi-directional so you would never need to define an XML map for
TestObjectPrime to TestObject. If these two classes had references to complex types that needed type
transformation, you would also define them as mappings. Dozer recursively goes through an object
and maps everything in it. Data type conversion is performed automatically. Dozer also supports no
attribute mappings at all. If supplied two classes that are not mapped, it simply tries to map properties
that are the same name.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

8 Basic Property Mapping

15

8 Basic Property Mapping

.......................................................................................................................................
8.1 Basic Property Mapping
8.1.1 Implicit Property Mapping (bi-directional)

Matching field names are automatically handled by Dozer.
Properties that are of the same name do not need to be specified in the mapping xml file.
8.1.2 Simple Mappings (bi-directional)

We will start off simple. If you have two properties with different names they can be mapped as such:


one
onePrime


8.1.3 Data type conversion

Data type coversion is performed automatically by the Dozer mapping engine. Currently, Dozer
supports the following types of conversions: (these are all bi-directional)
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•

Primitive to Primitive Wrapper
Primitive to Custom Wrapper
Primitive Wrapper to Primitive Wrapper
Primitive to Primitive
Complex Type to Complex Type
String to Primitive
String to Primitive Wrapper
String to Complex Type if the Complex Type contains a String constructor
String to Map
Collection to Collection
Collection to Array
Map to Complex Type
Map to Custom Map Type
Enum to Enum
Each of these can be mapped to one another: java.util.Date, java.sql.Date, java.sql.Time,
java.sql.Timestamp, java.util.Calendar, java.util.GregorianCalendar
• String to any of the supported Date/Calendar Objects.
• Objects containing a toString() method that produces a long representing time in (ms) to any
supported Date/Calendar object.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

8 Basic Property Mapping

16

8.1.4 Recursive Mapping (bi-directional)

Dozer supports full Class level mapping recursion. If you have any complex types defined as field
level mappings in your object, Dozer will search the mappings file for a Class level mapping between
the two Classes that you have mapped. If you do not have any mappings, it will only map fields that
are of the same name between the complex types.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

9 String To Date Mapping

17

9 String To Date Mapping

.......................................................................................................................................
9.1 String to Date Mapping
A date format for the String can be specified at the field level so that the necessary data type
conversion can be performed.


dateString
dateObject


A default date format can also be specified at the class mapping level. This default date format will be
applied to all field mappings unless it is overridden at the field level.


org.dozer.vo.TestObject
org.dozer.vo.TestObjectPrime

dateString
dateObject



A default date format can also be specified at the very top mappings level. This default date format
will be applied to all field mapppings unless it is overridden at a lower level

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

9 String To Date Mapping



MM/dd/yyyy HH:mm


org.dozer.vo.TestObject
org.dozer.vo.TestObjectPrime

dateString
dateObject



org.dozer.vo.SomeObject
org.dozer.vo.SomeOtherObject

srcField
destField




©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

18

10 Enum Mapping

10 Enum Mapping

19

.......................................................................................................................................
10.1 JDK 1.5 Enum Mapping
To map an enums value to another enum is shown below.


status
statusPrime


©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

10 Enum Mapping

enum Status {
PROCESSING, SUCCESS, ERROR
}
public class UserGroup {
private Status status;
public Status getStatus() {
return status;
}
public void setStatus(Status status) {
this.status = status;
}
}
enum StatusPrime {
PROCESSING, SUCCESS, ERROR
}
public class UserGroupPrime {
private StatusPrime statusPrime;
public StatusPrime getStatusPrime() {
return statusPrime;
}
public void setStatusPrime(StatusPrime statusPrime) {
this.statusPrime = statusPrime;
}
}

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

20

11 Collection Mapping

21

11 Collection Mapping

.......................................................................................................................................
11.1 Collection and Array Mapping
Dozer automatically maps between collection types and automatically performs any type conversion.
Each element in the source collection is mapped to an element in the dest object. Hints are used
to specify what type of objects are created in the destination collection. The following collection
mapping is automatically handled by Dozer: (These are all bi-directional)
•
•
•
•
•
•

List to List
List to Array
Array to Array
Set to Set
Set to Array
Set to List

11.1.1 Using Hints for Collection Mapping

Hints are not required if you are using JDK 1.5 Generics or Arrays because the types can be
autodetected by Dozer. But if you are not using generics or Arrays, to convert a Collection/Array to
a Collection/Array with different type objects you can specify a Hint to let Dozer know what type of
objects you want created in the destination list. If a Hint is not specified for the destination field, then
the destination Collection will be populated with objects that are the same type as the elements in the
src Collection.



hintList
hintList
org.dozer.vo.TheFirstSubClassPrime


Below is a summary of the mapping logic used when mapping Arrays, Sets, and Lists. This gives a
breakdown of what happens when hints are or are not used.
• List to List
•
• Dest Hint req'd: NO
• Dest Hint allowed: YES
• If no dest hint specified: Dest list will contain the same data types in the source
• If hint is speficied: Dest list will contain objects that match dest hint(s) type
• Array to List
•
• Dest Hint req'd: NO
• Dest Hint allowed: YES
• If no dest hint specified: Dest list will contain the same data types in the source
• If hint is speficied: Dest list will contain objects that match dest hint(s) type

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

11 Collection Mapping

22

• List to Array
•
• Dest Hint req'd: NO
• Dest Hint allowed: YES
• If no dest hint specified: Dest array will contain data types defined by the array
• If hint is speficied: Dest list will contain objects that match dest hint(s) type (only if Object
Array)
• Array to Array
•
• Dest Hint req'd: NO
• Dest Hint allowed: YES
• If no dest hint specified: Dest array will contain data types defined by the array
• If hint is speficied: Dest list will contain objects that match dest hint(s) type (only if Object
Array)
• Set to Set
•
• Dest Hint req'd: NO
• Dest Hint allowed: YES
• If no dest hint specified: Dest list will contain the same data types in the source
• If hint is speficied: Dest list will contain objects that match dest hint(s) type
• Array to Set
•
• Dest Hint req'd: NO
• Dest Hint allowed: YES
• If no dest hint specified: Dest list will contain the same data types in the source
• If hint is speficied: Dest list will contain objects that match dest hint(s) type
• Set to Array
•
• Dest Hint req'd: NO
• Dest Hint allowed: YES
• If no dest hint specified: Dest array will contain data types defined by the array
• If hint is speficied: Dest list will contain objects that match dest hint(s) type (only if Object
Array)
• List to Set
•
• Dest Hint req'd: NO
• Dest Hint allowed: YES
• If no dest hint specified: Dest list will contain the same data types in the source
• If hint is speficied: Dest list will contain objects that match dest hint(s) type
• Set to List
•
• Dest Hint req'd: NO
• Dest Hint allowed: YES
• If no dest hint specified: Dest list will contain the same data types in the source
• If hint is speficied: Dest list will contain objects that match dest hint(s) type
11.1.2 Using JDK 1.5 Generics for Collection Mapping

Hints are not required when JDK 1.5 Generics are used. To convert a Collection/Array to a
Collection/Array with different type objects dozer can determine parameterized types at runtime.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

11 Collection Mapping

23

public class UserGroup {
private Set users;
public Set getUsers() {
return users;
}
public void setUsers(Set aUsers) {
users = aUsers;
}
}
public class UserGroupPrime {
private List users;
public List getUsers() {
return users;
}
public void setUsers(List aUsers) {
users = aUsers;
}
}

11.1.3 Object Array to List (bi-directional)

When converting an Object array to a List, by default the destination List will contain the same data
type as the source Array.



arrayForLists
listForArray


Use a hint for data type conversion. Because a hint is specified, the destination List will contain String
elements instead of Integers.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

11 Collection Mapping

24



arrayForLists
listForArray
java.lang.String


11.1.4 Primitive Array to Primitive Array (bi-directional)

When converting an Object array to an Array, by default the destination Array will contain the same
data type as the source Array.



anArray
theMappedArray


11.1.5 Cumulative vs. Non-Cumulative List Mapping (bi-directional)

If you are mapping to a Class which has already been initialized, dozer will either 'add' or 'update'
objects to your List. If your List or Set already has objects in it dozer checks the mapped List, Set, or
Array and calls the contains() method to determine if it needs to 'add' or 'update'. This is determined
using the relationship-type attribute on the field tag. The default is 'cumulative'. relationship-type can
be specifed at the field mapping, class mapping, or global configuration level.
global configuration level....



non-cumulative



class mapping level....

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

11 Collection Mapping

25



org.dozer.vo.TestObject
org.dozer.vo.TestObjectPrime

someList
someList




field mapping level....



hintList
hintList
org.dozer.vo.TheFirstSubClass
org.dozer.vo.TheFirstSubClassPrime



unequalNamedList
theMappedUnequallyNamedList


Note: if you do not define custom equals() and hashCode() methods non-cumulative option will not
function properly, as Dozer will fail to determine object equality and will rely on JDK generated
object Ids. In default case two instances of a class are always treated as different and update will not
occure.
11.1.6 Removing Orphans

Orphans are elements which exist in a destination collection that did not exist within the source
collection. Dozer will remove orphans by calling the 'remove' method on actual orphans of the
underlying destination collection; it will not clear all. To determine elements which are orphans dozer
uses the contains() method to check if the results contains orphans. The default setting value is false.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

11 Collection Mapping



srcList
destList


©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

26

12 Map Backed Properties

27

12 Map Backed Properties

.......................................................................................................................................
12.1 Map Backed Property Mapping
12.1.1 Map to Map

Dozer will map a java.util.Map to a java.util.Map. If there are complex types with hints it will do deep
recursion mapping as well. If the destination map exists it will add elements to the existing map.


org.dozer.vo.map.MapToMap
org.dozer.vo.map.MapToMapPrime

standardMapWithHint
standardMapWithHint
org.dozer.vo.TestObject
org.dozer.vo.TestObjectPrime



12.1.2 Mapping Field Level Properties to a java.util.Map or a Custom Map with unique Get/Set
methods

Dozer supports mapping map backed properties at the field level. The map can either implement the
java.util.Map Interface or be a custom map with a set of unique Get/Set methods.
In this example Field A is a basic String and it is mapped to Field B which is a HashMap. The key
in the HashMap will be "stringProperty" (the attribute name) and the value will be whatever value is
stored in that attribute.


org.dozer.vo.map.PropertyToMap
org.dozer.vo.map.MapToProperty

stringProperty
hashMap



©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

12 Map Backed Properties

28

This example shows Field A is a basic String and it is mapped to Field B which is a HashMap. The
key in the HashMap will be "myStringProperty" and the value will be whatever value is stored in that
attribute. Also notice that Field A has a unique setter() method name.


org.dozer.vo.map.PropertyToMap
org.dozer.vo.map.MapToProperty

stringProperty2
hashMap



This example shows Field A is a basic String and it is mapped to Field B which is a custom map. The
key in the custom map will be "myCustomProperty" and the value will be whatever value is stored
in that attribute. Notice that Field B has unique map getter() and map setter() method names. If you
are using a custom map you must explicitly set the map Get/Set method names. A destination hint can
also be provided if your custom map implements an Interface or is an Abstract class.


org.dozer.vo.map.PropertyToMap
org.dozer.vo.map.MapToProperty

stringProperty3
customMap


stringProperty4
nullCustomMap
org.dozer.vo.map.CustomMap


stringProperty5
customMap



©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

12 Map Backed Properties

29

12.1.3 Mapping Class Level Properties to a java.util.Map or a Custom Map with unique Get/Set
methods

Dozer can also map entire complex objects directly to a java.util.Map or a custom map object. This
example shows the declaration of a mapping between a complex object (PropertyToMap) and a
java.util.Map. When doing this you need to explicitly define a unique map-id for the mapping. This
is used when determining which map to use at run-time. Every attribute on the PropertyToMap class
will be mapped to the java.util.Map. You DO NOT need to explicitly define these mappings. Field
exclude mappings can be used to exclude fields at run-time. If the attribute name is not the same as
the map key just set the key attribute for a custom field mapping. The mapping to stringProperty2
shows an example of this.
The second example shows how to setup a custom map object. The only difference here is that you
need to explicitly define map-set-method and map-get-method values. These correspond to the
java.util.Map get() and put() methods.


org.dozer.vo.map.PropertyToMap
java.util.Map

stringProperty2
this


excludeMe
this



org.dozer.vo.map.PropertyToMap

org.dozer.vo.map.CustomMap


stringProperty2
this


excludeMe
this



The example below shows how to use these mappings. Notice that the field mappings reference a
map-id. The first field mapping will use the myTestMapping defined mapping and map accordingly.
Same goes with the custom mapping.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

12 Map Backed Properties

30


org.dozer.vo.map.MapTestObject
org.dozer.vo.map.MapTestObjectPrime

propertyToMap
propertyToMapMap


propertyToMapToNullMap
nullPropertyToMapMap
java.util.HashMap


propertyToCustomMap
propertyToCustomMapMap



The Class Level map backed mappings can also be used as a standard mapping. For this dozer has a
new API. In addition to the source and destination classes you can now pass in the map reference Id.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

12 Map Backed Properties

// Example 1
PropertyToMap ptm = new PropertyToMap();
ptm.setStringProperty("stringPropertyValue");
ptm.addStringProperty2("stringProperty2Value");
Map map = Mapper.map(ptm, HashMap.class, "myTestMapping");
// Example 2
CustomMap customMap = mapper.map(ptm, CustomMap.class,
"myCustomTestMapping");
// Example 3
CustomMap custom = new CustomMap();
custom.putValue("myKey", "myValue");
Mapper.map(ptm, custom, "myCustomTestMapping");
// Example 4 - Map Back
Map map = new HashMap();
map.put("stringProperty", "stringPropertyValue");
PropertyToMap property = mapper.map(map, PropertyToMap.class,
"myTestMapping");
assertEquals("stringPropertyValue", property.getStringProperty());

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

31

13 Index Mapping

13 Index Mapping

32

.......................................................................................................................................
13.1 Indexed Property Mapping
Fields that need to be looked up or written to by indexed property are supported.


org.dozer.vo.Individuals
org.dozer.vo.FlatIndividual

usernames[0]
username1


usernames[1]
username2


individual.username
username2


secondNames[1]
secondName1


secondNames[2]
secondName2


aliases.otherAliases[0]
primaryAlias



©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

14 Deep Mapping

33

14 Deep Mapping

.......................................................................................................................................
14.1 Deep Property Mapping
It is possible to map deep properties. An example would be when you have an object with a String
property. Your other object has a String property but it is several levels deep within the object graph.
In the example below the DestDeepObj has nested attributes within the object graph that need to
be mapped. Type hints are supported for deep field mappings. The attributes copy-by-reference,
type=one-way, and relationship-type can also be used.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

14 Deep Mapping


org.dozer.vo.deep.SrcDeepObj
org.dozer.vo.deep.DestDeepObj

srcNestedObj.src1
dest1


srcNestedObj.src2
dest2


srcNestedObj.srcNestedObj2.src5
dest5


srcNestedObj.hintList
hintList
java.lang.String
java.lang.Integer


srcNestedObj.hintList2
hintList2
org.dozer.vo.TheFirstSubClass
org.dozer.vo.TheFirstSubClassPrime


srcNestedObj.hintList3
hintList3



14.2 Deep Indexed Mapping
Indexed mapping within deep mapping is supported.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

34

14 Deep Mapping

35


offSpringName
pets[1].offSpring[2].petName


Destination Hints are NOT required if the indexed collection is an Array or if you are using jdk 1.5
Generics. Dozer is able to automatically determine the property type for these use cases. But you will
need to provide hints if the data types are not Arrays or if you are not using Generics. This is required
so that Dozer knows what types of dest objects to create while it traverses the deep field mapping.
The following is an example of using hints.....


someField
someList[1].someOtherList[0].someOtherField
org.dozer.vo.TestObject,
org.dozer.vo.AnotherTestObject



©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

15 Excluding Fields

36

15 Excluding Fields

.......................................................................................................................................
15.1 Excluding Fields
Dozer supports excluding fields from a mapping using the field-exclude tag. We also support field
excludes going one-way as shown in the example.


fieldToExclude
fieldToExclude


fieldToExclude
fieldToExclude


15.1.1 Wildcard - excluding default field mappings

There's also a flag ( wildcard) set on class mapping which controls whether the default mapping
(which applies to pair of properties of the same name) should be done. The default value is true. For
example:


org.dozer.vo.AnotherTestObject
org.dozer.vo.AnotherTestObjectPrime

field1
field1



This configuration would cause only the fields field1 in both classes to be mapped, even if both
classes share a property with the same name called field2.
15.1.2 Exclude Mapping Null Values

You can bypass the mapping of null values. If this is specified, the dest field mapping is bypassed at
runtime and the destination value setter method will not be called if the src value is null. This can be
specified at the mapping or class level. For example:

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

15 Excluding Fields


org.dozer.vo.AnotherTestObject
org.dozer.vo.AnotherTestObjectPrime

field4
to.one



OR...


org.dozer.vo.AnotherTestObject
org.dozer.vo.AnotherTestObjectPrime


field4
to.one



15.1.3 Exclude Mapping Empty Strings

You can bypass the mapping of empty String values. If this is specified, the dest field mapping is
bypassed at runtime and the destination value setter method will not be called if the src value is an
empty String. This can be specified at the mapping or class level. For example:


org.dozer.vo.AnotherTestObject
org.dozer.vo.AnotherTestObjectPrime

field4
to.one



OR...

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

37

15 Excluding Fields


org.dozer.vo.AnotherTestObject

org.dozer.vo.AnotherTestObjectPrime


field4
to.one



©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

38

16 One-Way Mapping

39

16 One-Way Mapping

.......................................................................................................................................
16.1 One-Way Mapping
You can set how a mapping definition behaves as far as direction goes. If you only want to map two
classes to go one-way you can set this at the mapping level. The default is bi-directional. This can be
set at the mapping level OR the field level. When one-way is specified, "a" is always the src object
and "b" is always the destination object.


org.dozer.vo.TestObjectFoo
org.dozer.vo.TestObjectFooPrime

oneFoo
oneFooPrime



In the following example the one-way fields are only mapped when "a" object is mapped to "b"
object. If "b" is mapped to "a", then the field is not mapped.


org.dozer.vo.TestObjectFoo2
org.dozer.vo.TestObjectFooPrime2

oneFoo2
oneFooPrime2


oneFoo3.prime
oneFooPrime3


16.1.1 Excluding Fields One-Way

Dozer supports field excludes going one-way as shown in the example. In the example the field is
only excluded when "a" is mapped to "b". If "b" is mapped to "a", then the field is not excluded.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

16 One-Way Mapping


fieldToExclude
fieldToExclude


©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

40

17 Context Based Mapping

17 Context Based Mapping

41

.......................................................................................................................................
17.1 Context Based Mapping
Context based mapping can be specified by using the map-id attribute. Note that we also support
nested context mapping by specifying a map-id at the field level.


org.dozer.vo.context.ContextMapping
org.dozer.vo.context.ContextMappingPrime

loanNo
loanNo


contextList
contextList
org.dozer.vo.context.ContextMappingNestedPrime




org.dozer.vo.context.ContextMapping
org.dozer.vo.context.ContextMappingPrime


org.dozer.vo.context.ContextMappingNested
org.dozer.vo.context.ContextMappingNestedPrime


loanNo
loanNo



org.dozer.vo.context.ContextMappingNested
org.dozer.vo.context.ContextMappingNestedPrime




To use a particular context when invoking the Mapper, you simply specify the map-id in your
mapping call.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

17 Context Based Mapping

ContextMappingPrime cmpA =
mapper.map(cm, ContextMappingPrime.class, "caseA");

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

42

18 Global Configuration

43

18 Global Configuration

.......................................................................................................................................
18.1 Global Configuration
The configuration block is used to set the global default settings. Also, any Custom Converters are
defined in this section. The configuration block is entirely "optional".
Dozer supports the ability to have multiple mapping files, but only one global configuration across the
multiple mapping files. We recommend having a separate mapping xml file for specifying the single
global configuration. Implicit mappings will inherit the default values for configuration.
The following is the sample configuration block:


MM/dd/yyyy HH:mm
true
true
false
 

org.dozer.vo.TestCustomConverterObject
another.type.to.Associate




18.2 Overriding Wildcards
Each individual mapping section can set its own wildcard policy even if there is a global wildcard
policy defined using the configuration block. For example, the following mapping does not allow
wildcards:


org.dozer.vo.SpringBean
org.dozer.vo.SpringBeanPrime

anAttributeToMap
anAttributeToMapPrime



©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

18 Global Configuration

44

18.3 Overriding Date Format
The same is true for date format values. Each individual mapping section can set its own date format
rules. For example:



org.dozer.vo.TestObject
org.dozer.vo.TestObjectPrime

one
onePrime



18.4 Overriding Error Handling
You can override the error handling policy for a particular mapping. For example:



org.dozer.vo.TestObject
org.dozer.vo.TestObjectPrime

one
onePrime



18.5 Overriding Trim Strings Policy
You can override the trim strings policy for a particular mapping. For example:

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

18 Global Configuration



org.dozer.vo.TestObject
org.dozer.vo.TestObjectPrime

one
onePrime



©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

45

19 Custom Converters

46

19 Custom Converters

.......................................................................................................................................
19.1 Custom Converters
Custom converters are used to perform custom mapping between two objects. In the Configuration
block, you can add some XML to tell Dozer to use a custom converter for certain class A and class B
types. When a custom converter is specified for a class A and class B combination, Dozer will invoke
the custom converter to perform the data mapping instead of the standard mapping logic.
Your custom converter must implement the org.dozer.CustomConverter interface in order for Dozer
to accept it. Otherwise an exception will be thrown.
Custom converters are shared across mapping files. This means that you can define them once in a
mapping file and it will be applied to all class mappings in other mapping files that match the Class
A - Class B pattern. In the example below, whenever Dozer comes across a mapping where the src/
dest class match the custom converter definition, it will invoke the custom converter class instead of
performing the typical mapping.




 

org.dozer.vo.CustomDoubleObject
java.lang.Double




org.dozer.vo.TestCustomConverterHashMapObject


org.dozer.vo.TestCustomConverterHashMapPrimeObject






Custom converters can also be specified at the individual field level. In the example below, Dozer will
invoke the custom converter to perform the field mapping.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

19 Custom Converters

47


org.dozer.vo.SimpleObj
org.dozer.vo.SimpleObjPrime2

field1
field1Prime



Custom converter 'instances' can be reused at the individual field level. In the example below, Dozer
will invoke the custom converter to perform the field mapping.


org.dozer.vo.SimpleObj
org.dozer.vo.SimpleObjPrime2

field1
field1Prime



CustomConverter instances need to be injected into the DozerBeanMapper if you need to do some
manipulation with them before they are used in dozer. They can also be set programmatically on the
DozerBeanMapper if you do not use Spring.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

19 Custom Converters

48







systempropertymapping1.xml
dozerBeanMapping.xml
injectedCustomConverter.xml








Sample custom converter implementation:
Note: Custom Converters get invoked when the source value is null, so you need to explicitly handle
null values in your custom converter implementation.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

19 Custom Converters

public class TestCustomConverter implements CustomConverter {
public Object convert(Object destination, Object source,
Class destClass, Class sourceClass) {
if (source == null) {
return null;
}
CustomDoubleObject dest = null;
if (source instanceof Double) {
// check to see if the object already exists
if (destination == null) {
dest = new CustomDoubleObject();
} else {
dest = (CustomDoubleObject) destination;
}
dest.setTheDouble(((Double) source).doubleValue());
return dest;
} else if (source instanceof CustomDoubleObject) {
double sourceObj =
((CustomDoubleObject) source).getTheDouble();
return new Double(sourceObj);
} else {
throw new MappingException("Converter TestCustomConverter "
+ "used incorrectly. Arguments passed in were:"
+ destination + " and " + source);
}
}

CustomConverters can also be injected into the DozerBeanMapper if you need to do some
manipulation with them before they are used in dozer.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

49

19 Custom Converters

50







systempropertymapping1.xml
dozerBeanMapping.xml
injectedCustomConverter.xml











injectedName




19.1.1 Support for Array Types

You can specify a custom converter for Array types. For example, if you want to use a custom
converter for mapping between an array of objects and a String you would use the following mapping
notation. Dozer generically uses ClassLoader.loadClass() when parsing the mapping files. For arrays,
java expects the class name in the following format.... [Lorg.dozer.vo.SimpleObj;


[Lorg.dozer.vo.SimpleObj;
java.lang.String


©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

19 Custom Converters

51

19.1.2 Support for primitives

You can specify a custom converter for primitive types. Just use the primitive wrapper class when
defining the custom coverter mapping. In the following example, Dozer will use the specified custom
converter when mapping between SomeObject and the int primitive type. Note that Dozer will also
use the custom converter when mapping between SomeObject and the Integer wrapper type.


somePackage.SomeObject
java.lang.Integer


19.1.3 Configurable Custom Converters

You can define a custom converter, which can be configured from mappings via configuration
parameter. In this case you should implement ConfigurableCustomConverter interface instead of
usual CustomConverter. Configurable converter has additional attribute provided in runtime - param.
Parameter is provided using custom-converter-param attribute.


org.dozer.vo.BeanA
org.dozer.vo.BeanB

amount
amount



Configurable custom converter should be used when you have similar behaviour in many cases, which
can be parametrized, but the number of conbinations is too high to do simple Custom Converter
subclassing.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

19 Custom Converters

52

public class MathOperationConverter
implements ConfigurableCustomConverter {
public Object convert(Object destinationFieldValue,
Object sourceFieldValue,
Class destinationClass,
Class sourceClass, String param) {
Integer source = (Integer) sourceFieldValue;
Integer destination = (Integer) destinationFieldValue;
if ("+".equals(param)) {
return destination.intValue + source.intValue();
}
if ("-".equals(param)) {
return destination.intValue - source.intValue();
}
}
}

19.1.4 New Custom Converter API

While providing great deal of flexibility Custom Converter API described above is written on fairly
low levele of abstraction. This results in converter, which code is difficult to understand and to reuse
in other ways than plugging into Dozer mapping. However it is not uncommon situation when the
same convertation logic should be called from a place other than bean mapping framework.
Latest version of Dozer gets shipped with new - cleaner API for defining custom converter, which
gives you more obvious API while taking away certain part of control of the executions flow. The
following example demonstrates simple, yet working converter using new API.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

19 Custom Converters

53

public class NewDozerConverter
extends DozerConverter {
public NewDozerConverter() {
super(String.class, Boolean.class);
}
public Boolean convertTo(String source, Boolean destination) {
if ("yes".equals(source)) {
return Boolean.TRUE;
} else if ("no".equals(source)) {
return Boolean.FALSE;
}
throw new IllegalStateException("Unknown value!");
}
public String convertFrom(Boolean source, String destination) {
if (Boolean.TRUE.equals(source)) {
return "yes";
} else if (Boolean.FALSE.equals(source)) {
return "no";
}
throw new IllegalStateException("Unknown value!");
}
}

Note that Java 5 Generics are supported and you do not need to cast source object to desired type as
previously.
19.1.5 Data Structure Conversions

There are cases where it is required to perform programmatic data structure conversion, say copy
each odd element in a list as map key, but each even as map value. In this case it is needed to define
transformation of the structure while relying on usual Dozer mapping support for individual values.
For this purposes it is possible to use MapperAware interface, which injects current mapper instance
inside custom converter.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

19 Custom Converters

public static class Converter
extends DozerConverter  implements MapperAware {
private Mapper mapper;
public Converter() {
super(List.class, Map.class);
}
public Map convertTo(List source, Map destination) {
Map originalToMapped = new HashMap();
for (Source item : source) {
Target mappedItem = mapper.map(item, Target.class);
originalToMapped.put(item, mappedItem);
}
return originalToMapped;
}
<...>
public void setMapper(Mapper mapper) {
this.mapper = mapper;
}
}

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

54

20 Custom Bean Factories

55

20 Custom Bean Factories

.......................................................................................................................................
20.1 Custom Bean Factories
You can configure Dozer to use custom bean factories to create new instances of destination data
objects during the mapping process. By default Dozer just creates a new instance of any destination
objects using a default constructor. This is sufficient for most use cases, but if you need more
flexibility you can specify your own bean factories to instantiate the data objects.
Your custom bean factory must implement the org.dozer.BeanFactory interface. By default the Dozer
mapping engine will use the destination object class name for the bean id when calling the factory.

public interface BeanFactory {
public Object createBean(Object source, Class sourceClass,
String targetBeanId);
}

Next, in your Dozer mapping file(s) you just need to specify a bean-factory xml attribute for any
mappings that you want to use a custom factory.
In the following example, the SampleCustomBeanFactory will be used to create any new instances of
the InsideTestObjectPrime java bean data object.


com.example.vo.InsideTestObject

com.example.vo.InsideTestObjectPrime



If your factory looks up beans based on a different id than class name, you can specifiy a factorybean-id xml attribute. At runtime the specified factory-bean-id will be passed to the factory instead of
class name.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

20 Custom Bean Factories


com.example.vo.InsideTestObject

com.example.vo.InsideTestObjectPrime



20.1.1 Specifying Default Factories

Alternatively, bean factories can be specified in the default configuration section of any Dozer
mapping file(s). The default factory would be used for any mappings in that file.


true
true
com.example.factories.SomeDefaultBeanFactory



Bean factories can also be specified at the mapping level. The specified factory would be used for
class-a and class-b.


com.example.vo.TestObject
com.example.vo.TestObjectPrime


20.1.2 Spring bean factory injection

Bean factories can be injected via Spring or similar inversion of control techniques.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

56

20 Custom Bean Factories

57





systempropertymapping1.xml
dozerBeanMapping.xml









By defining your factories as Spring beans you can then inject them into the DozerBeanMapper class.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

21 Custom Create Methods

21 Custom Create Methods

58

.......................................................................................................................................
21.1 Custom Create Methods
You can configure Dozer to use custom static create methods to create new instances of destination
data objects during the mapping process. This can either be set at the field level or class level.



org.dozer.vo.InsideTestObject

org.dozer.vo.InsideTestObjectPrime

label
labelPrime



Specifying a custom create method at the Field level....


org.dozer.vo.TestObject
org.dozer.vo.TestObjectPrime

createMethodType
createMethodType



It is also possible to reference different class with static factory method. This is done by providing
fully qualified type name and method name separated by dot.

...
field
...

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

22 Custom Get/Set Methods

59

22 Custom Get/Set Methods

.......................................................................................................................................
22.1 Custom get() set() Methods
22.1.1 Mapping a field with no get() or set() methods

Use the attribute is-accessible to declare that the field can be accessed directly. Dozer is able to access
private properties that do not have getter or setter methods.


fieldAccessible
fieldAccessible


22.1.2 Custom Set() and Get() methods (bi-directional)

For those beans that might have unorthodox getter and setter methods, Dozer support user specified
setter and getter methods. To make a bi-directional mapping in this case, look at the following
example below. The source field in element A specifies a custom setter method and getter method
using attributes.


value
value


In this case we are mapping a String to an ArrayList by calling the addIntegerToList() method. Note
that this is defined as a one-way field type since we can not map an ArrayList to a String.



integerStr
integerList


22.1.3 Overloaded Set() methods (bi-directional)

Sometimes set() methods can be overloaded. In order to chose the correct one you can add the class
type as a parameter.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

22 Custom Get/Set Methods

60


overloadGetField

overloadSetField



22.1.4 Iterate Method Mapping (bi-directional)

Dozer also supports iterate method level mapping. In the following example the List appleComputers
will be iterated through and for each object the method addComptuer will be called. Any field that is
denoted as type=iterate requires a hint. The get() method can return an Array, List, or Iterator.


appleComputers
computers
org.dozer.vo.AppleComputer


Below is an example with iterate methods on both fields.


iterateCars
iterateCars
org.dozer.vo.Car
org.dozer.vo.Car


©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

23 Copy By Ref Mapping

61

23 Copy By Ref Mapping

.......................................................................................................................................
23.1 Copying By Object Reference
Dozer supports copying an object by reference. No conversion/transformation is done for such
objects. This approach allows to decrease a number of object allocations, but is applicable only
when Java Beans are to be thrown away (Garbage Collected) after transformation. This approach is
generally recommended for performance tuning of the mapping process when possible. Make sure
that both object types are the same or you will run into casting problems. The default value is 'false'.


copyByReference
copyByReferencePrime


This is also supported at the class level. Just define the classes you want to be copied by reference in
the configuration block.


...


org.dozer.vo.NoExtendBaseObjectGlobalCopyByReference




On the class level wildcard expressions are allowed. Copy by reference is applied via mask, which
can inlcude multiple wildcard (*) characters.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

23 Copy By Ref Mapping

62


...


org.dozer.vo.*


org.dozer.*.vo.*DTO




23.1.1 Referencing self (this) in a field mapping

Using a field mapping it is possible to map where N == 0 (self, or this). In the following example
SimpleAccount is mapped to Address. It is also mapped to Account. Suppose Address was an
attribute on Account. How could we map the values on SimpleAccount to that property? The answer
is to use the keyword (this) to denote using the class being mapped as the source object.


org.dozer.vo.self.SimpleAccount
org.dozer.vo.self.Account

this
address



org.dozer.vo.self.SimpleAccount
org.dozer.vo.self.Address

streetName
street



©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

24 Inheritance Mapping

63

24 Inheritance Mapping

.......................................................................................................................................
24.1 Inheritance Mapping
24.1.1 Reducing Mapping XML when using base class attributes

Properties that are of the same name do not need to be specified in the mapping xml file unless
hints are needed.
If you are mapping subclasses that also have have base class attributes requiring mapping XML,
you might be inclined to reproduce base class field maps in each subclass mapping element, like the
following example:


org.dozer.vo.SubClass
org.dozer.vo.SubClassPrime


superAttribute
superAttr


attribute2
attributePrime2



org.dozer.vo.SubClass2
org.dozer.vo.SubClassPrime2


superAttribute
superAttr


attribute2
attributePrime2



In the previous mapping, some of the fields were from a common base class, but you had to reproduce
them into each mapping of the sub classes.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

24 Inheritance Mapping

64

However, a better way to do it would be to map the base class individually. This can be done for each
base class (in the case of a larger heirarchy). Assuming the base class name, below is the refactored
mapping xml:


org.dozer.vo.SuperClass
org.dozer.vo.SuperClassPrime

superAttribute
superAttr



org.dozer.vo.SubClass
org.dozer.vo.SubClassPrime

attribute
attributePrime



org.dozer.vo.SubClass2
org.dozer.vo.SubClassPrime2

attribute2
attributePrime2



The following images explain some of the different scenarios dozer handles. Each diagram shows two
mapped class hierarchies and existing relations, which Dozer recognizes and maps.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

24 Inheritance Mapping

Scenario 1 shows that if you map SubClass to ClassPrime all attributes from SuperClass ->
ClassPrime will be mapped as well.

Scenario 2 shows that Dozer has no limitations on the inheritance depth it analyzes to find parent
mappings.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

65

24 Inheritance Mapping

66

Scenario 3 shows that it is possible to map two collections with different subctypes of the same parent
type. This is done by providing hints to the collection mapping, describing all potential subclasses.


aList
bList
B1,B2
BPrime1,BPrime2


©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

25 Dozer Events

67

25 Dozer Events

.......................................................................................................................................
25.1 Event Listening
By implementing the DozerEventListener interface dozer allows you to listen to 4 different events:
• mappingStarted
• mappingFinished
• preWritingDestinationValue
• postWritingDestinationValue
A DozerEvent object is passed into these callback methods which stores information about the
ClassMap, FieldMap, Source object, destination object, and destination value. This will allow you to
extend dozer and manipulate mapped objects at run-time. The interface is shown below:

public interface DozerEventListener {
public void mappingStarted(DozerEvent event);
public void preWritingDestinationValue(DozerEvent event);
public void postWritingDestinationValue(DozerEvent event);
public void mappingFinished(DozerEvent event);
}

The listeners that you create can be injected to the DozerBeanMapper using an IOC like Spring or set
directly on your DozerBeanMapper instance by using the setEventListeners() method. Below is an
example using Spring to inject an event listener:

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

25 Dozer Events







dozerBeanMapping.xml











©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

68

26 Expression Language

69

26 Expression Language

.......................................................................................................................................
26.1 Expression Language
26.1.1 Usage

Dozer provides optional support for standard java expression language (javax.el).
Current support for expressions is start-up time only. Expressions are not resolved during each
mapping, but rather during Xml mapping file loading procedure. Each attribute or node value can
contain a valid EL expression ${}.
Dozer supports any EL implementation written against javax.el standard API. Functionality is tested
with JUEL internally, but other EL providers should be working as well.
You can define global variables for the mapper in variables configuration block.


true

org.dozer.sample.MyType



${type_name}
...


26.1.2 Enabling

EL support is an optional feature. If it is not enable it does not affect mapping performance neither it
requires additional Jar dependencies to your project.
In order to enable EL expression execution dozer.el.enabled parameter should be set to true.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

27 Configuration

70

27 Configuration

.......................................................................................................................................
27.1 Configuration
Dozer configuration properties can be customized via an optional Dozer properties file. By default,
Dozer will look for a file named dozer.properties to load configuration properties. If a properties file
is not found or specified, default values will be used.
Dozer is distributed with an example dozer.properties file in /config that shows the various options.
Just put the example file in your classpath and customize it.
An alternative Dozer properties file can be specified via the dozer.configuration system property. ex) Ddozer.configuration=someDozerConfigurationFile.properties
Dozer Configuration Properties
Property Name

Description

Valid Values

Default

dozer.statistics.enabled

Specifies whether
Dozer collects runtime
mapping statistics.
Note that statistics
gathering imposes certain
performance overhead.
It is not recommended
to enable this option in
production settings under
heavy load.

true|false

false

dozer.autoregister.jmx.beansSpecifies whether Dozer
will auto register it's
JMX beans with the
PlatformMDBServer on
startup.

true|false

true

dozer.el.enabled

true|false

false

dozer.cache.converter.by.dest.type.maxsize
Specifies the max size
for one of Dozers internal
caches.

0 - Long.MAX_VALUE

10000

dozer.cache.super.type.maxsize
Specifies the max size
for one of Dozers internal
caches

0 - Long.MAX_VALUE

10000

org.dozer.util.DozerProxyResolver
Specifies implementation
of DozerProxyResolver to
be used

Valid class name

Default implementation

org.dozer.util.DozerClassLoader
Specifies implementation
of DozerClassLoader to
be used

Valid class name

Default implementation

Specifies whether during
Xml mappings parsing
Dozer will recognize EL
expressions.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

27 Configuration

27.2 Debugging Initialization
One time Dozer initialization information can be optionally sent to System.out to help with
debugging.
To enable this additional debugging info, set the dozer.debug system property.
ex) -Ddozer.debug=true
Types of information that will be sent to System.out are loading of configuration file, loading of
custom xml mapping files, version info, classloader info

dozer: Trying to find Dozer configuration file: dozer.properties
dozer: Using URL [file:/local/subversion_projects/dozer/trunk/ta
rget/test-classes/dozer.properties] for Dozer global property con
figuration
dozer: Reading Dozer properties from URL [file:/local/subversion
_projects/dozer/trunk/target/test-classes/dozer.properties]
dozer: Finished configuring Dozer global properties
dozer: Initializing Dozer. Version: ${project.version}, Thread
Name:main
dozer: Dozer JMX MBean [org.dozer.jmx:type=DozerStatisticsContr
oller] auto registered with the Platform MBean Server
dozer: Dozer JMX MBean [org.dozer.jmx:type=DozerAdminController
] auto registered with the Platform MBean Server
dozer: Initializing a new instance of the dozer bean mapper.
dozer: Initializing a new instance of the dozer bean mapper.
dozer: Using the following xml files to load custom mappings fo
r the bean mapper instance: [fieldAttributeMapping.xml]
dozer: Trying to find xml mapping file: fieldAttributeMapping.x
ml
dozer: Using URL [file:/local/subversion_projects/dozer/trunk/t
arget/test-classes/fieldAttributeMapping.xml] to load custom xml
mappings
dozer: Successfully loaded custom xml mappings from URL: [file:
/local/subversion_projects/dozer/trunk/target/test-classes/field
AttributeMapping.xml]

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

71

28 Logging

72

28 Logging

.......................................................................................................................................
28.1 Logging
The logging facade framework in Dozer is SLF4J. It replaced Commons Logging, which was used in
project previously until version 5.3.
Please refer to SLF4J Documentation for more information on setting up and configuring different
logging implementations.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

29 Proxy Handling

73

29 Proxy Handling

.......................................................................................................................................
29.1 Proxy Objects
29.1.1 Overview

Dozer supports mappings done on proxy objects. This is typically the case when using persistence
framework, which supports sophisticated features like lazy-loading. In this case application is
working with fake objects, containing the real objects encapsulated. Implementation of proxies is
dependant on the technology you use. Generally speaking, there are two popular libraries for creating
Java proxies ( Cglib and Javassist). However, how particular framework makes uses of them could
also vary. Dozer offers by default a generic way to handle simple proxy scenarios, both Javassist
and Cglib. However it is strongly recommended to tune proxy handling behavior for your particular
scenario.
29.1.2 Configuration

Proxy implementation is set-up by modifying configuration file. Currently, besides of default
behavior, Hibernate and No-Proxy modes are supported. For the full list of the implementations, see
the list of org.dozer.util.DozerProxyResolver interface implementations. The list could be retrieved
from JavaDocs.
In case you do not map proxied objects - use NoProxy resolver, which imposes minimum
performance overhead.
29.1.3 Custom Scenarios

For custom scenarios it is possible to provide your own implementation of
org.dozer.util.DozerProxyResolver interface. It is configured in the same way as the standard classes.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

30 Statistics

74

30 Statistics

.......................................................................................................................................
30.1 Statistics
If you enable statistics, Dozer will collect a number of runtime mapping metrics. These statistics are
global and can be accessed via the GlobalStatistics object. The statistics are also available via JMX.
Dozer is distributed with a fully functional JMX DozerStatisticsControllerMBean.
Based on our profiling numbers, the overhead of enabling statistics is roughly 3-5%.
Dozer Statistics
Statistic Type

Description

Mapping Success Count

# of successful mappings

Mapping Failure Count

# of failed mappings

Mapping Overall Time

Overall time(ms) of successful mappings

Mapping Avg Time

Average time(ms) of successful mappings

Mapping Failure Exception Types

# of failures per exception type. This statistic shows
what specific exceptions are being thrown when
mappings fail

Mapping Failure Type

# of failures per source and destination class names.
This statistic shows which specific mappings have
failed per unique src class name and dest class name

Mapper Instances Count

# of DozerBeanMapper objects created. This should
be a low number

Field Mapping Success Count

# of successful field mappings

Field Mapping Failure Count

# of failed field mappings

Field Mapping Failure Ignored Count

# of failed field mappings that were ignored during
the mapping process. By default, Dozer throws an
exception when any field mappings fail. But this
behavior can be overridden. This statistic is useful to
understand the impacts of setting stop-on-errors to
false

Cache Hit Count

# of hits per internal Dozer cache type

Cache Miss Count

# of misses per internal Dozer cache type

Custom Converter Overall Time

Overall time(ms) of successful custom converter
mappings

Custom Converter Success Count

# of successful custom converter mappings

Custom Converter Percentage of Overall Time

Percentage of overall time spent in custom converter
mappings

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

31 JMX Integration

75

31 JMX Integration

.......................................................................................................................................
31.1 JMX Integration
Dozer can be managed via JMX. The Dozer distibution contains fully functional JMX MBeans. These
MBeans can be found in the org.dozer.jmx package.
Dozer auto registers these JMX Beans with the PlatformMBeanServer. You can suppress this
behavior with the following Dozer configuration property:
dozer.autoregister.jmx.beans = false
Dozer JMX MBeans
MBean

Description

DozerStatisticsControllerMBean

Runtime mapping statistics. The Statistics section
contains more information on the types of statistics
that are available.

DozerAdminControllerMBean

Admin functions such as enabling/disabling statistics
gathering at runtime.

Note that JMX MBeans are potential source of memory leaks. MBeans should be disposed properly
when application is stopped or restarted as in most of todays Web Containers there is no full
JVM restart. The proper way to unregister all Dozer JMX Beans is to call destroy() method on
DozerBeanMapper object.
31.1.1 Sample JMX Screen Shots

Dozer JMX MBeans via JConsole.....

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

31 JMX Integration

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

76

32 Spring Integration

77

32 Spring Integration

.......................................................................................................................................
32.1 Spring Framework Integration
Since version 5.5.0 Spring integration comes within additional module dozer-spring.
Add the DozerBeanMapperFactoryBean to your Spring configuration file. The mappingFiles property
is where you should specify any custom dozer mapping files that you have created. This list can be
empty if you don't have any custom mappings. It is also possible to set custom event listeners and
bean factories.
Note that this Factory Bean supports Spring Resources, which means that you could load mapping
Xml files by classpath mask for example.

















IMPORTANT: You shoud define the Dozer mapper bean is defined as singleton="true". You
should configure the Mapper instance(s) this way so that you do not have to reload and reinitialize
the mapping files for each individual mapping during the lifecycle of your app. Reinitializing the
mapping files for each mapping would be inefficent and unnecessary. The DozerBeanMapper class is
thread safe.
If you want to avoid clashing of mapping definitions for different functionality it is possible to define
own DozerBeanMapper instance for each such use case.
A simpler way of registering mapper instance is without wrapping factory bean.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

32 Spring Integration




dozer-global-configuration.xml
dozer-bean-mappings.xml
more-dozer-bean-mappings.xml




Using Spring to retrieve the Dozer Mapper......

Mapper mapper = yourSpringBeanFactory.getBean("mapperBeanName");
DestinationObject destObject =
mapper.map(sourceObject, DestinationObject.class);

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

78

33 JAXB and XMLBeans

33 JAXB and XMLBeans

79

.......................................................................................................................................
33.1 3rd Party Object Factories
Dozer supports mapping of plain Java objects to frameworks that require instantiation of objects
via certain convention of calling factory methods. To reproduce the expected behavior custom bean
factories should be used.
33.1.1 Mapping JAXB Objects

Dozer has support for mapping POJOs to JAXB objects. Use the JAXBBeanFactory for any JAXB
objects you want create.


org.dozer.vo.TestObject

org.dozer.vo.jaxb.employee.Employee


name
firstName


street
address.street


33.1.2 Mapping XMLBeans

Dozer has support for mapping POJOs to XMLBeans objects. Use the XMLBeanFactory for any
XMLBeans you want created. This factory will also be used for mapping any fields that need to be
instantiated in a deep mapping that are not regular POJOs but are XMLBeans.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

33 JAXB and XMLBeans


org.dozer.vo.TestObject

org.dozer.vo.GetWeatherByZipCodeDocument


one
GetWeatherByZipCode.zipCode



The unit test:

// Map from TestObject to XMLBeans
TestObject to = new TestObject();
to.setOne("one");
GetWeatherByZipCodeDocument doc =
mapper.map(to, GetWeatherByZipCodeDocument.class);
assertEquals(to.getOne(),
doc.getGetWeatherByZipCode().getZipCode());
// Map from XMLBeans to TestObject
GetWeatherByZipCodeDocument res =
GetWeatherByZipCodeDocument.Factory.newInstance();
GetWeatherByZipCode zipCode =
res.addNewGetWeatherByZipCode();
zipCode.setZipCode("one");
TestObject to2 = mapper.map(res, TestObject.class);
assertEquals(res.getGetWeatherByZipCode().getZipCode(),
to2.getOne());

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

80

34 Metadata Query Interface

81

34 Metadata Query Interface

.......................................................................................................................................
34.1 Querying mapping metadata
This section will cover the mapping metadata interface. It provides easy to use read-only access to all
important properties or aspects of the currently active mapping definitions.
The following sections will give some code examples how to use the mapping query interfaces. The
most important interface in the whole process is org.dozer.metadata.MappingMetadata. An instance
can be acquired by calling the getMappingMetadata() method of the DozerBeanMapper class. This
call will initialize the mappings if the map method has not been called yet.
Consider the following mapping file:




org.dozer.vo.ClassA
org.dozer.vo.ClassB

fieldA
fieldB




To begin querying the mapping definitions the following code is needed:

DozerBeanMapper mapper = new DozerBeanMapper();
mapper.setMappingFiles(listOfFiles);
MappingMetadata mapMetadata = beanMapper.getMappingMetadata();

Now that a reference to MappingMetadata is obtained we can start querying for a certain class
mapping definition:

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

34 Metadata Query Interface

82

try {
ClassMappingMetadata classMappingMetadata =
mapMetadata.getClassMapping(ClassA.class, ClassB.class);
} catch (MetadataLookupException e) {
// couldn't find it
}

When holding a reference to a ClassMappingMetadata interface, queries for individual field mappings
can be executed:

try {
FieldMappingMetadata fieldMetadata =
classMetadata.getFieldMappingBySource("fieldA");
// Destination: fieldB
System.out.println("Destination: " +
fieldMetadata.getDestinationName());
} catch (MetadataLookupException e) {
// couldn't find it
}

For extensive documentation on the different interfaces please refer to the JavaDoc.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

35 FAQ

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35 FAQ

.......................................................................................................................................
35.1 Frequently Asked Questions
35.1.1 Common

•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•

What types of data objects are supported?
Will Dozer automatically perform data type conversions?
Does Dozer automatically map fields with matching property names?
Is Dozer recursive?
Will the getter and setter methods be invoked when fields are mapped?
Are Collections and Arrays supported?
Are Map type objects(i.e HashMap) supported?
Are abstract classes, inheritance, and interface mapping supported?
Can Dozer be configured via Spring?
Which types of data mappings do I need a custom xml mapping definition for?
If my src and dest object have all matching attribute names, do I need to specify any xml
mapping definitions at all?
For mappings that require an xml mapping definition, is the mapping definition bi-directional, or
do I need 2 xml definitions if I need to map the two objects both ways?
How are the custom xml mapping files loaded?
Can I load a mapping file that is not in the classpath?
How can I tell if Dozer is initializing correctly and loading my xml mapping files?
How does Dozer perform?
Which JDK versions are supported?
Is Dozer in the maven repository?
Is Dozer good for the environment?

35.1.2 Advanced

• Can I implement custom mapping logic between 2 data types and have Dozer invoke this custom
logic when it's performing mappings?
• Can I map one field into another field that is nested n layers deep in the destination object?
• How do I map multiple fields to a single field?
• If I am mapping data objects that have bi-directional relationships, will it result in an infinite
loop and eventual stack overflow error?
• How do I map an object contained in a collection to a field?
• How do I map a Complex object to a HashMap and vice versa?
• How do I map fields that don't have corresponding getter/setter methods?
• Some of my data objects don't have public constructors. Does Dozer support this use case?
• Does Dozer support JDK 1.5 enums?
• Does Dozer support XMLBeans and JAXB generated data objects?
• Is there an Eclipse plugin or visual editor for Dozer?
• When mapping collections, how do I tell Dozer what type of data objects I want in the
destination collection?
• How can I tell Dozer to bypass mapping null or empty string values?

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

35 FAQ

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• How do I enable Dozer to collect runtime mapping statistics?
35.1.3 Tips, Tricks, and Suggestions

•
•
•
•
•
•
•
•

Should I encapsulate logic that copies data between objects?
Should I write unit tests for data mapping logic that I use Dozer to perform?
Should the Dozer mapper be configured as a Singleton?
Is it better to have 1 large xml mapping file or to have multiple smaller mapping files?
What is the best way to view runtime mapping statistics?
What are the best ways to debug Dozer?
What is the best way to setup the global configuration?
What is the best way to submit a bug, feature request, or patch?

35.2 Answers

35.2.1 What types of data objects are supported?

Dozer uses reflection to access data object properties, so it is designed to work with data objects
that have corresponding getter and setter methods for its fields. For example, a data object that has
a field named "message" should have getMessage and setMessage methods. Data objects that don't
follow this pattern are also supported, but will most likely require a custom mapping definition. For
these unorthodox data objects, you can tell Dozer to directly access fields(including private) and/or
explicitly specify which get/set methods to use.

35.2.2 Will Dozer automatically perform data type conversions?

Yes. Most scenarios are supported out of the box. These include primitives, Java Wrapper Objects,
Number subclasses, Dates, Calendar, Collections, Arrays, Maps, and Complex types

35.2.3 Does Dozer automatically map fields with matching property names?

Yes. All fields with matching property names are implicitly mapped. It would be atypical usage, but
you could suppress this behavior by setting wilcard="false".

35.2.4 Is Dozer recursive?

Yes. Dozer recursively maps the entire object graph for all fields.

35.2.5 Will the getter and setter methods be invoked when fields are mapped?

Yes. You can bypass this default behavior by explicitly specifying is-accessible="true" for any of
your mappings. If is-accessible is specified, the field(including private fields) is accessed directly and
the getter/setter methods are bypassed. It is not recommended that you set is-accessible="true", unless
you are dealing with an unorthodox data object that does not contain any getter or setter methods.

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35.2.6 Are Collections and Arrays supported?

Yes. Dozer automatically maps between collection types and automatically performs any type
conversion.

35.2.7 Are Map type objects(i.e HashMap) supported?

Yes. All Java Map data types are supported in addition to any Custom map data types.

35.2.8 Are abstract classes, inheritance, and interface mapping supported?

Yes.

35.2.9 Can Dozer be configured via Spring?

Yes. Refer to Spring Integration section of the documentation.

35.2.10 Which types of data mappings do I need a custom xml mapping definition for?

Only fields that can't be implicitly mapped by matching on field name, need a custom xml mapping
definition. Ideally, the vast majority of your field mappings can be performed automatically and only
the few exceptional cases will need an explicit field mapping in the xml mapping file.

35.2.11 If my src and dest object have all matching attribute names, do I need to specify any xml
mapping definitions at all?

Nope. Just invoke the mapper. You don't need any explicit xml mapping entries for this combination
of source and destination object.

35.2.12 For mappings that require an xml mapping definition, is the mapping definition bidirectional, or do I need 2 xml definitions if I need to map the two objects both ways?

All mapping definitions are bi-directional, so you only need one mapping definition. You can map a -> b and b--> a using this single mapping definition.

35.2.13 How are the custom xml mapping files loaded?

Dozer will search the entire classpath looking for the specified file(s).

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

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86

35.2.14 Can I load a mapping file that is not in the classpath?

Yes, you can load files from outside the classpath by prepending "file:" to the resource name. Ex)
"file:c:\somedozermapping.xml"

35.2.15 How can I tell if Dozer is initializing correctly and loading my xml mapping files?

Set the -Ddozer.debug system property. If this is set, Dozer initialization information is also sent to
System.out. If you are familiar with log4j, this is similar to the -Dlog4j.debug system property

35.2.16 How does Dozer perform?

We believe Dozer performs very well and performance is a high priority for us. We have spent a
significant amount of time profiling the code and optimizing bottlenecks.
Performance is going to depend on the complexity of the use case and the number of fields mapped.
In our performance tests for "average" mapping scenarios, the class mapping times vary from 1/8
of a millisecond to 2 milliseconds. This roughly equates to 50 - 450 field mappings per millisecond.
However, the number of variables in any decent benchmark makes it almost impossible to transfer
these results into reasonable conclusions about the performance of your own application. Your
application is different and you will have unique use cases.
Dozer has been successfully implemented on large, very high transactional enterprise systems,
without any resulting performance issues. But we always recommend that you run performance tests
on your application to determine the actual performance costs within your system. You can decide for
yourself whether those costs are acceptable in the context of the entire system.
If you want to see actual Dozer runtime mapping statistics within the context of a system/application,
you can enable Dozer statistics. This would be a good way to determine actual mapping times as
a percentage of overall system performance. The best way to view the stats is via the Dozer JMX
Beans. With the 3.2 release, these JMXBeans are auto registered with the platform mdb server.
JConsole is a good way to easily view the MBeans.
Based on our profiling numbers, the overhead of enabling statistics is roughly 3-5%.

35.2.17 Which JDK versions are supported?

JDK 1.5 and above.

35.2.18 Is Dozer in the maven repository?

Yes and we will continue to do our best to get future releases of Dozer uploaded into the repository.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

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87


net.sf.dozer
dozer
${project.version}


35.2.19 Is Dozer good for the environment?

Yes, dozer does not burn any fossil fuels and is within the EPA's recommended emissions.

35.2.20 Can I implement custom mapping logic between 2 data types and have Dozer invoke this
custom logic when it's performing mappings?

Yes. A very useful feature provided by Dozer is the concept of custom converters. Custom converters
are used to perform custom mapping between two objects. In the Configuration block, you can add
some XML to tell Dozer to use a custom converter for certain class A and class B types. When a
custom converter is specified for a class A and class B combination, Dozer will invoke the custom
converter to perform the data mapping instead of the standard mapping logic.



org.dozer.vo.SomeCustomDoubleObject
java.lang.Double



35.2.21 Can I map one field into another field that is nested n layers deep in the destination object?

Yes. Dozer supports dot notation for nested fields. As with other dozer field mappings, these are bidirectional.


someNestedObj.someOtherNestedObj.someField
someOtherField


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35 FAQ

88

35.2.22 How do I map multiple fields to a single field?

Dozer doesn't currently support this. And because of the complexities around implementing it, this
feature is not currently on the road map. A possible solution would be to wrap the multiple fields in a
custom complex type and then define a custom converter for mapping between the complex type and
the single field. This way, you could handle the custom logic required to map the three fields into the
single one within the custom converter.

35.2.23 If I am mapping data objects that contain bi-directional relationships, will it result in an
infinite loop and eventual stack overflow error?

No. Dozer has built in logic that prevents infinite loops for bi-directional data object relationships

35.2.24 How do I map an object contained in a collection to a field?

You would use indexed based mapping.


usernames[0]
username1


35.2.25 How do I map a Complex object to a HashMap and vice versa?

You can map entire complex objects directly to a java.util.Map and vice versa. When doing this you
need to explicitly define a unique map-id for the mapping. This is used when determining which map
to use at run-time. Every attribute on the complex type will be mapped to the java.util.Map. You DO
NOT need to explicitly define these mappings. If the attribute name is not the same as the map key
just set the key attribute for a custom field mapping.


org.dozer.vo.map.SomeComplexType
java.util.Map

stringProperty2
this


©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

35 FAQ

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35.2.26 How do I map fields that don't have corresponding getter/setter methods?

You can tell Dozer to directly access fields(including private fields) by specifying is-accessible="true"


fieldA
fieldB


35.2.27 Some of my data objects don't have public constructors. Does Dozer support this use case?

Yes. When creating a new instance of the destination object if a public no-arg constructor is not
found, Dozer will auto detect a private constructor and use that. If the data object does not have
a private constructor, you can specify a custom BeanFactory for creating new instances of the
destination object.

35.2.28 Does Dozer support JDK 1.5 enums?

Yes. Enum to Enum mapping is automatically handled.

35.2.29 Does Dozer support XMLBeans and JAXB generated data objects?

Dozer supports mapping POJOs to XMLBeans objects. Use the XMLBeanFactory for any XMLBeans
you want created. This factory will also be used for mapping any fields that need to be instantiated in
a deep mapping that are not regular POJOs but are XMLBeans.
Dozer has support for mapping POJOs to JAXB objects. Use the JAXBBeanFactory for any JAXB
objects you want created.

35.2.30 Is there an Eclipse plugin or visual editor for Dozer?

No, but we think it would be a great addition. It would be very powerful to be able to graphically map
2 objects and have the custom xml definitions auto generated, along with being able to visually view a
mapping definition. If anyone has expertise in creating eclipse plugins and is interested on working on
this feature, please let us know!

35.2.31 When mapping collections, how do I tell Dozer what type of data objects I want in the
destination collection?

Hints are supported to handle this use case. Hints are not required if you are using JDK 1.5 Generics
because the types can be auto detected by Dozer. But if you are not using generics, to convert a
Collection/Array to a Collection/Array with different type objects you can specify a Hint to let Dozer
know what type of objects you want created in the destination list. If a Hint is not specified for the

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

35 FAQ

90

destination field, then the destination Collection will be populated with objects that are the same type
as the elements in the src Collection.


someList
otherList
org.dozer.vo.TheFirstSubClassPrime


35.2.32 How can I tell Dozer to bypass mapping null or empty string values?

You can bypass the mapping of null values by specifying map-null="false". If this is specified, the
dest field mapping is bypassed at runtime and the destination value setter method will not be called if
the src value is null. This can be specified at the mapping or class level.
You can bypass the mapping of empty String values by specifying map-empty-string="false". If this
is specified, the dest field mapping is bypassed at runtime and the destination value setter method will
not be called if the src value is an empty String. This can be specified at the mapping or class level

35.2.33 How do I enable Dozer to collect runtime mapping statistics?

In your dozer.properties file set "dozer.statistics.enabled=true"

35.2.34 Should I encapsulate logic that copies data between objects?

It is our opinion that you should. Regardless of whether you use Dozer to perform data mapping
between objects, we believe this is a good design pattern that promotes reuse, encapsulates the
underlying implementation, and makes the code unit testable in isolation. These "Assembler"
interfaces encapsulate the logic that is responsible for taking a src object and mapping the data into
a dest object. Using assembler type of classes gives you the flexibility of being able to modify the
underlying mapping implementation without impacting clients or the contract. One other important
benefit of using Assemblers is that it makes writing unit tests specific for the mapping a lot easier
and more focused. If you ever need to determine if a particular bug is due to mapping of objects, it
is simple to write an Assembler unit test that reproduces the use case. If you encapsulate your data
mapping logic, you could use Dozer for most of mappings and if you have a real corner case, you
have the flexibility to hand code mappings for any objects or fields. For example, you could run your
mapping through Dozer to map 99% of your fields and then have a manual mapping for some odd
ball field. This would happen all within the Assembler without the client having any knowledge of the
underlying implementation.
It seems to work best if these assembler type of classes are "dumb" and are only responsible for
simply copying data from the source object into the destination object. Any complex postprocessing
business logic that needs to be performed on the destination object can be done at a higher level in
classses that have more responsibility.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

35 FAQ

91

The following is a simple example of an assembler type class that uses Dozer for its underlying
implementation.

public class SomeAssemblerImpl implements SomeAssembler {
private Mapper dozerMapper;
public DestObject assembleDestObject(SrcObject src) {
return dozerMapper.map(src, DestObject.class);
}
}

35.2.35 Should I write unit tests for data mapping logic that I use Dozer to perform?

Absolutely. And of course, we strongly recommend writing the unit test(s) first. Even if you don't use
Dozer to perform the data mapping between two objects, this logic still needs isolated unit tests. Data
mapping logic(especially hand coded) is error prone and having a unit test is invaluable. Typically
mapping between two objects is required in multiple areas of a system, so a focused unit test of the
central mapping logic enables you to test the data mapping logic in isolation. The great thing about
encapsulating data mapping logic and having unit tests for the logic is that you can easily switch out
the underlying implementation.
For existing systems that are wanting to migrate to Dozer, we recommend first encapsulating any
existing hand coded data mapping into an assembler type of class and write unit tests for it. Then
switch out the hand coded mapping logic with Dozer and the unit tests will be your safety net. The
migration to Dozer can be incremental and this is probably the best strategy for exisiting systems.
Regardless of whether or not you use Dozer, unit testing data mapping logic is tedious and a
necessary evil, but there is a trick that may help. If you have an assembler that supports mapping 2
objects bi-directionally, in your unit test you can do something similar to the following example. This
also assumes you have done a good job of implementing the equals() method for your data objects.
The idea is that if you map a source object to a destination object and then back again, the original src
object should equal the object returned from the last mapping if fields were mapped correctly. In the
test case, you should populate all the possible fields in the original source object to ensure that all of
the fields are accounted for in the mapping logic.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

35 FAQ

92

public void testAssembleSomeObject() throws Exception {
SrcObject src = new SrcObject();
src.setSomeField("somevalue");
src.setSomeOtherField("make sure you set all the src fields "
+ "with values so that you fully test the data mappings");
DestObject dest = assembler.assembleDestObject(src);
SrcObject mappedSrc = assermbler.assembleSrcObject(dest);
assertEquals("fields not mapped correctly", src, mappedSrc);
}

It is also good practice to verify that your assembler handles null values properly. In the following test
case none of the source fields are populated. If the assembler doesn't properly handle null values, an
exception will be thrown when the assembler is invoked.

public void testAssembleSomeObject_NullValues() throws Exception {
SrcObject src = new SrcObject();
DestObject dest = assembler.assembleDestObject(src);
SrcObject mappedSrc = assermbler.assembleSrcObject(dest);
assertEquals("fields not mapped correctly", src, mappedSrc);
}

35.2.36 Should the Dozer mapper be configured as a Singleton?

Yes. Mapper instance(s) should be setup as a Singleton. For every instance of the DozerBeanMapper,
the mapping files are loaded and parsed. You should configure the Mapper as a singleton so that you
only incur the cost of loading and initializing the mapping files 1 time. The DozerBeanMapper class is
thread safe.

35.2.37 Is it better to have 1 large xml mapping file or to have multiple smaller mapping files?

We recommend componentizing your mapping files instead of having 1 large mapping file.

35.2.38 What is the best way to view runtime mapping statistics?

The best way to view the runtime stats is via the Dozer JMX Beans. These JMXBeans are auto
registered with the platform mdb server at startup. JConsole is a good way to easily view the MBeans.

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

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35.2.39 What are the best ways to debug Dozer?

You can specify the -Ddozer.debug system property to view the one time initialization information.
You will see output similar to the following....
dozer: Trying to find Dozer configuration file: dozer.properties
dozer: Using URL [file:/local/subversion_projects/dozer/trunk/ta
rget/test-classes/dozer.properties] for Dozer
global property configuration
dozer: Reading Dozer properties from URL
[file:/local/subversion_projects/dozer/trunk/target/test-classes
/dozer.properties]
dozer: Finished configuring Dozer global properties
dozer: Initializing Dozer. Version: ${project.version}, Thread N
ame:main
dozer: Dozer JMX MBean [org.dozer.jmx:type=DozerStatisticsContro
ller] auto registered with the Platform MBean
Server
dozer: Dozer JMX MBean [org.dozer.jmx:type=DozerAdminController]
auto registered with the Platform MBean
Server
dozer: Initializing a new instance of the dozer bean mapper.
dozer: Initializing a new instance of the dozer bean mapper.
dozer: Using the following xml files to load custom mappings for
the bean mapper instance:
[fieldAttributeMapping.xml]
dozer: Trying to find xml mapping file: fieldAttributeMapping.xm
l
dozer: Using URL [file:/local/subversion_projects/dozer/trunk/ta
rget/test-classes/fieldAttributeMapping.xml]
to load custom xml mappings
dozer: Successfully loaded custom xml mappings from URL:
[file:/local/subversion_projects/dozer/trunk/target/test-classes
/fieldAttributeMapping.xml]

To debug individual field mappings between classes, set the logging level
"org.dozer.MappingProcessor=DEBUG". For example, if you are using
log4j you would add the following entry to your log4j configuration file
"log4j.category.org.dozer.MappingProcessor=DEBUG". This will show you every field mapping that
Dozer performs along with the actual source and destination values. You will see output similar to the
following....

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.

35 FAQ

94

MAPPED: SimpleObj.field1 --> SimpleObjPrime.field1
one --> one MAPID: someMapId
MAPPED: SimpleObj.field2 --> SimpleObjPrime.field2
2 --> 2 MAPID: someMapId
MAPPED: SimpleObj.field3 --> SimpleObjPrime.field3
3 --> 3 MAPID: someMapId
MAPPED: SimpleObj.field4 --> SimpleObjPrime.field4
44.44 --> 44.44 MAPID: someMapId
MAPPED: SimpleObj.field6 --> SimpleObjPrime.field6
66 --> 66 MAPID: someMapId

VALUES:
VALUES:
VALUES:
VALUES:
VALUES:

35.2.40 What is the best way to setup the global configuration?

We recommend having a separate mapping xml file for global configuration. You could name it
something similar to dozer-global-configuration.xml. Sample global configuration file......




true
MM/dd/yyyy HH:mm
false


org.dozer.vo.CustomDoubleObject
java.lang.Double



}

35.2.41 What is the best way to submit a bug, feature request, or patch?

We value your suggestions and appreciate everyone that takes the time to submit a support request.
Please submit all requests via Dozer's Sourceforge project page

©2014, Franz Garsombke, Matt Tierney, Dmitry Buzdin • ALL RIGHTS RESERVED.



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