Specifying EclipseLink MOXy as Your JAXB Provider

To specify EclipseLink MOXy as the JAXB provider you need to put a jaxb.properties file in one of the packages for your domain classes, that is passed in to bootstrap the JAXBContext.

Java Model

Our Java model will consist of the following two classes that reference each other.  This is important because when you bootstrap a JAXBContext on a class, the classes that it references are also processed.   I have also put these classes in separate packages so that we can examine the impact of where you put the jaxb.properties file.

example.foo.Foo

package example.foo;

import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;

import example.bar.Bar;

@XmlAccessorType(XmlAccessType.FIELD)
public class Foo {

    private Bar bar;

}

example.bar.Bar

package example.bar;

import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;

import example.foo.Foo;

@XmlAccessorType(XmlAccessType.FIELD)
public class Bar {

    private Foo foo;

}

example/foo/jaxb.properties

To specify that the MOXy implementation of JAXB should be used we will put a jaxb.properties file with the following entry in the same package as the Foo class.

javax.xml.bind.context.factory=org.eclipse.persistence.jaxb.JAXBContextFactory

Demo Code

Since the Foo and Bar classes reference each other, ultimately the JAXBContext will contain metadata about both of them, but based on how we create the JAXBContext the provider can be different.  In order for the jaxb.properties file to be processed it must be in the same package as at least one of the domain classes specified when bootstrapping the JAXBContext.

package example;

import javax.xml.bind.JAXBContext;
import example.foo.Foo;
import example.bar.Bar;

public class Demo {

    public static void main(String[] args) throws Exception{
        System.out.println(JAXBContext.newInstance(Foo.class).getClass());
        System.out.println(JAXBContext.newInstance(Bar.class).getClass());
        System.out.println(JAXBContext.newInstance(Foo.class, Bar.class).getClass());
    }

}

Running the above code will produce:

class org.eclipse.persistence.jaxb.JAXBContext
class com.sun.xml.bind.v2.runtime.JAXBContextImpl
class org.eclipse.persistence.jaxb.JAXBContext

You will notice that when we bootstrapped the JAXBContext on the Bar class we did not MOXy as our JAXB provider. This is because none of the classes we passed to create the JAXBContext were from a package that contained a jaxb.properties file.  This is the intended behaviour, and something to be aware of when specifying a JAXB provider.


Further Reading

Once you are able to configure EclipseLink MOXy as your JAXB provider you can take advantage of its many extensions:

• Extending JAXB - Representing Metadata as XML
• XPath Based Mapping - Geocode Example
• Map to Element based on an Attribute Value with EclipseLink JAXB (MOXy)
• JPA Entities to XML - Bidirectional Relationships
• CDATA, CDATA Run, Run Data Run
• @XmlTransformation - Going Beyond XmlAdapter