I don't like this approach since it's adding Seam dependency to your model. Unnecessary complexity.

Plus the code for setting the created and creator can be refactored out to an Interceptor, DAO layer, EntityHome (if your using Seam Framework) or even an event listener and applied to all the object who implement an interface, say CreatorAware or something.

my $.02

You probably want to use an ejb3 entity listener to listen for the postLoad event, something like:

orm.xml:

<persistence-unit-metadata>
        <persistence-unit-defaults>
            <entity-listeners>
                      
                <entity-listener class="com.example.EntityLister">
                    <pre-persist method-name="prePersist"/>
                    
                </entity-listener>
            </entity-listeners>
        </persistence-unit-defaults>
</persistence-unit-metadata>

Have an interface as follows:

interface CreatorAware
{
  public void setCreator(User u);
  public User getCreator();
}

and then in the entity lister:

class EntityLister
{

 public void prePersist(Object entity)
 {
  if(CreatorAware.class.isAssignableFrom(entity.getClass())
  {
     CreateAware a = (CreatorAware)entity;
     if(a.getCreator() == null)
     {
          a.setCreator((Usr) Component.getInstance("currentUsr", ScopeType.SESSION));
     }
  }
 }

}

Take a look at

JPA-Hibernate Event Listener: http://tinyurl.com/5k764b

Hibernate Event Listener: http://tinyurl.com/5dj5uu

Seam Interceptors: http://tinyurl.com/6c9lqb