Detach an entity from JPA/EJB3 persistence context

Question

What would be the easiest way to detach a specific JPA Entity Bean that was acquired through an EntityManager. Alternatively, could I have a query return detached objects in

Answer 1

If you need to detach an object from the EntityManager and you are using Hibernate as your underlying ORM layer you can get access to the Hibernate Session object and use the Session.evict(Object) method that Mauricio Kanada mentioned above.

public void detach(Object entity) {
    org.hibernate.Session session = (Session) entityManager.getDelegate();
    session.evict(entity);
}

Of course this would break if you switched to another ORM provider but I think this is preferably to trying to make a deep copy.