/**
 * Invoked by Marshaller after it has created an instance of this object.
 */
boolean beforeMarshal(Marshaller m);
 
/**
 * Invoked by Marshaller after it has marshalled all properties of this object.
 */
void afterMarshal(Marshaller m);
 
/**
 * This method is called immediately after the object is created and before the unmarshalling of this 
 * object begins. The callback provides an opportunity to initialize JavaBean properties prior to unmarshalling.
 */
void beforeUnmarshal(Unmarshaller u, Object parent);
 
/**
 * This method is called after all the properties (except IDREF) are unmarshalled for this object, 
 * but before this object is set to the parent object.
 */
void afterUnmarshal(Unmarshaller u, Object parent);

package example;
 
import java.util.Date;
import java.util.logging.Logger;
import javax.xml.bind.annotation.*;
 
@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
public class Company {
 
   @XmlAttribute
   private String id;
 
   boolean beforeMarshal(Marshaller m) {
      Logger.getLogger("example").info("COMPANY:[id=" + id + "] " + Thread.currentThread());
      return true;
   }
 
   void afterMarshal(Marshaller m) {
      Logger.getLogger("example").info("COMPANY:[id=" + id + "] " + Thread.currentThread());
   }
 
   void beforeUnmarshal(Unmarshaller u, Object parent) {
      Logger.getLogger("example").info("COMPANY:[id=" + id + "] " + Thread.currentThread());
   }
 
   void afterUnmarshal(Unmarshaller u, Object parent) {
      Logger.getLogger("example").info("COMPANY:[id=" + id + "] " + Thread.currentThread());
   }
 
}

package javax.xml.bind;
 
public interface Marshaller {
   ...
   public static abstract class Listener {
     /**
      * Callback method invoked before marshalling from source to XML.
      *
      * This method is invoked just before marshalling process starts to marshal source.
      * Note that if the class of source defines its own beforeMarshal method,
      * the class specific callback method is invoked just before this method is invoked.
      *
      * @param source instance of JAXB mapped class prior to marshalling from it.
      */
      public void beforeMarshal(Object source) {}
 
     /**
      * Callback method invoked after marshalling source to XML.
      *
      * This method is invoked after source and all its descendants have been marshalled.
      * Note that if the class of source defines its own afterMarshal method,
      * the class specific callback method is invoked just before this method is invoked.
      *
      * @param source instance of JAXB mapped class after marshalling it.
      */
      public void afterMarshal(Object source) {}
   }
}

package javax.xml.bind;
 
public interface Unmarshaller {
   ...
   public static abstract class Listener {
 
     /**
      * Callback method invoked before unmarshalling into target.
      *
      * This method is invoked immediately after target was created and
      * before the unmarshalling of this object begins. Note that
      * if the class of target defines its own beforeUnmarsha method,
      * the class specific callback method is invoked before this method is invoked.
      *
      * @param target non-null instance of JAXB mapped class prior to unmarshalling into it.
      * @param parent instance of JAXB mapped class that will eventually reference target.
      *               null when target is root element.
      */
      public void beforeUnmarshal(Object target, Object parent) {}
 
     /**
      * Callback method invoked after unmarshalling XML data into target.
      *
      * This method is invoked after all the properties (except IDREF) are unmarshalled into target,
      * but before target is set into its parent object.
      * Note that if the class of target defines its own afterUnmarshal method,
      * the class specific callback method is invoked before this method is invoked.
      *
      * @param target non-null instance of JAXB mapped class prior to unmarshalling into it.
      * @param parent instance of JAXB mapped class that will reference target.
      *               null when target is root element.
      */
      public void afterUnmarshal(Object target, Object parent) {}
   }
}

package example;
 
import java.util.logging.Logger;
 
private class MarshalLogger extends Marshaller.Listener {
   @Override
   public void afterMarshal(Object source) {
      Logger.getLogger("example").info(source + " "   + Thread.currentThread());
   }
 
   @Override
   public void beforeMarshal(Object source) {
      Logger.getLogger("example").info(source + " "   + Thread.currentThread());
   }
}

package example;
 
import java.util.logging.Logger;
 
private class UnmarshalLogger extends Unmarshaller.Listener {
   @Override
   public void afterUnmarshal(Object target, Object parent) {
      Logger.getLogger("example").info(target + " "   + Thread.currentThread());
   }
 
   @Override
   public void beforeUnmarshal(Object target, Object parent) {
      Logger.getLogger("example").info(target + " "   + Thread.currentThread());
   }
}

Marshaller marshaller = jaxbContext.createMarshaller();
marshaller.setListener(new MarshalLogger());
 
Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
unmarshaller.setListener(new UnmarshalLogger());