@MappedSuperclass
public abstract class AbstractDV implements Serializable,PropertyChangeListener  {
	private static final long serialVersionUID = 1L;
	
	@Transient
	protected PropertyChangeSupport changeSupport = new PropertyChangeSupport(this); ;

        // constructor
        public AbstractDV() {
       	       changeSupport = new PropertyChangeSupport(this);    	
        }
	
	public void addPropertyChangeListener(String propertyName,
			PropertyChangeListener listener) {
		changeSupport.addPropertyChangeListener(propertyName, listener);
	}

...

}

@Entity
@Table(name="DV")
public class DV extends AbstractDV implements Serializable  {
...
       public DV() {
		super();
	}
...
}