@Entity
@EntityListeners(MyDescriptorEventAdapter.class)
public class Order {

   @Id
   @Column(name="ID")
   private Integer id;

   @OneToOne(fetch = FetchType.LAZY)
   @JoinColumn(name = "RL _ID", referencedColumnName = "ID")
   private RecordLogger recordLogger = null;
	
   @Column(name="DESCRIPTION")
   private String description = null;

   [...]

   private RecordLogger getRecordLogger() {
      if(this.recordLogger == null) {
        this.recordLogger = new RecordLogger();
      }
      return this.recordLogger;
   }

   private void setRecordLogger(RecordLogger recordLogger) {
      this.recordLogger = recordLogger;
   }

}

@Entity
@EntityListeners(MyDescriptorEventAdapter.class)
public class RecordLogger {

    @Id
    @Column(name="ID")
    private Integer id;
	
    @Column(name="CHANGE_ME")
    private Timestamp changeMe = null;

    [...]
	
    private Timestamp getChangeMe() {
      return this.changeMe;
    }
	
    private void setChangeMe(Timestamp changeMe) {
      this.changeMe = changeMe;
    }	
}

public class MyDescriptorEventAdapter extends DescriptorEventAdapter {

    @Override
    public void aboutToUpdate(DescriptorEvent event) {
        System.out.println("### aboutToUpdate: " + event.getObject().getClass().getName());
        ((Order)event.getObject()).getRecordLogger().setChangeMe(new Timestamp(System.currentTimeMillis()));
        super.aboutToUpdate(event);
    }

    @Override
    public void preUpdate(DescriptorEvent event) {
        System.out.println("### preUpdate: " + event.getObject().getClass().getName());
        ((Order)event.getObject()).getRecordLogger().setChangeMe(new Timestamp(System.currentTimeMillis()));
        super.preUpdate(event);
    }

    @Override
    public void preUpdateWithChanges(DescriptorEvent event) {
        System.out.println("### preUpdateWithChanges: " + event.getObject().getClass().getName());
        ((Order)event.getObject()).getRecordLogger().setChangeMe(new Timestamp(System.currentTimeMillis()));
        super.preUpdateWithChanges(event);
    }

}