Hibernate version: 3.0 final

Is there a way that hibernate could inject the session into a persistent object ?

I had a quick look but couldn't find a solution with the lifecycle and callback methods. Maybe i overlooked.

regards, tom.

The way I understand Hibernate, the object really doesn't have a clue that it's being managed, meaning it doesn't really have a handle to its associated session (if there is one). The obvious exception is with proxies and lazy loading...the proxy object has to have a reference to the session in order to perform the lazy load. If by "inject" a session into a persistent object you mean attaching the persistent object to a session, this can be accomplished by calling session.lock( object, LockMode.NONE ) or session.update( object ). This will associate a proxy with the (new?) session and allow lazy loading to occur.

I imagine that you could add a session property to your POJOs and write an interceptor that would set the session property during lifecycle events so that the object has a handle to the session. I don't think that such an approach is recommended, however, as there is a potential to have a handle to the wrong session stored somewhere in one of your POJOs. It might also introduce some interesting side-effects if you are using proxies if you are using those.

The ThreadLocal pattern (HibernateUtil) with a request interceptor (javax.servlet.Filter) has worked well for me and I think is considered a best practice. Rather than associating the session with an object it is associated with the Thread, so your scoping concerns are mitigated.

- Jesse

i know it's not recommended, but i can't use the interceptor method

boolean onLoad(Object entity, Serializable id, Object[] state, String[] propertyNames, Type[] types)

since it doesn't give me a pointer to the session.

regards, tom.

This is *really* not recommended, but you could use the Lifecycle interface to acheive this. In general though, like Jesse mentioned, it is not a good idea for your domain entities to have any knowledge of a Hibernate Session (or Hibernate-specific classes at all for that matter).