JAXB using MOXy - how to override property serialization behavior? - jaxb

Question

I have two classes
class First{
private Date date;
public Date getDate(){
return date;
}
...
}
and
class Second extends First{
#XmlAttribute
#XmlJavaTypeAdapter(value = DateAdapter.class, type = Date.class)
public Date getDate() {
return super.getDate();
}
}
Where DateAdapter just translates Date to Long and back.
I'm serializing an instance of the Second class and it seems to be that DateAdapter is ignored. I mean I get string "2013-05-22T13:32:40.664" instead of its Long representation.
If I'll move the #XmlJavaTypeAdapter annotation to the First class, it works OK, but my problem is that First can't be modified and that is basically the reason I created the wrapper class Second.
How can I make XmlJavaTypeAdapter be recognized?

Answer 1

You can use EclipseLink JAXB (MOXy)'s external binding file to provide metadata for classes that cannot be modified:
oxm.xml
<?xml version="1.0"?>
<xml-bindings
xmlns="http://www.eclipse.org/eclipselink/xsds/persistence/oxm"
package-name="com.example.foo">
<java-types>
<java-type name="First">
<java-attributes>
<xml-element java-attribute="date">
<xml-java-type-adapter value="com.example.foo.DateAdapter"/>
</xml-element>
</java-attributes>
</java-type>
</java-types>
</xml-bindings>
Demo
Then you can bootstrap your JAXBContext using a property specifying the metadata location:
import java.util.*;
import javax.xml.bind.JAXBContext;
import org.eclipse.persistence.jaxb.JAXBContextProperties;
public class Demo {
public static void main(String[] args) throws Exception {
Map<String, Object> properties = new HashMap<String, Object>();
properties.put(JAXBContextProperties.OXM_METADATA_SOURCE, "com/example/foo/oxm.xml");
JAXBContext jc = JAXBContext.newInstance(new Class[] {First.class, Second.class}, properties);
}
}
For More Information
http://blog.bdoughan.com/2010/12/extending-jaxb-representing-annotations.html