PersistentCollection - why no public getSession()?

plas · **Joined:** Fri May 05, 2006 11:15 am **Posts:** 6

Hello!
I have got a flag indicating that permits lazy initialization or else throw an exception (no matter how, lets say FlagHolder.isLIAllowed(Session session)) and I would like a code like this work for me:

Code:

if (value instanceof HibernateProxy) {
    session = ((HibernateProxy) value).getHibernateLazyInitializer().getSession();
} else if (value instanceof PersistentCollection) {
    session = ???
}

However, it is impossible to extract session information from an instance of PersistentCollection in current version of Hibernate (or I did not found any way of doing this?). Searching the net i found that in version 2.1.4 there was public getSession() in PersistentCollection interface, now if it is gone is it illegal to extract such info from PersistentCollection?

Thanks in advance, Marcin

Hibernate version:3.1.3

max · **Posted:** Tue May 09, 2006 5:10 am

Why would you ever want to access the internal session ?

That sounds like a baad dependency.

plas · **Joined:** Fri May 05, 2006 11:15 am **Posts:** 6

Well, it sounded innocent to me when I was thinking about it, the only thing I do is checking if a certain flag (my own) is set with session that owns proxy object, like this:

Code:

SessionImplementor session;
// obtain SessionImplementor like in the code above
if (!FlagHolder.isLazyInitAllowed(session)) {
    throw new SorryLazyInitializationIsTurnedOffException();
}
// do rest of code

The availability of HibernateProxy.getHibernateLazyInitializer().getSession() made my hunger of same thing available at PersistentCollection side, so is it all invalid to do?

max · **Posted:** Tue May 09, 2006 6:01 am

why would lazy initialization ever be associated with the session ?

you mean you check session.isClosed() ?

if yes; why don't you know (from somewhere else) what the current session is ?

plas · **Joined:** Fri May 05, 2006 11:15 am **Posts:** 6

I don't want to check anything that has to do with internal state of session, the flag is just a boolean value held inside my FlagHolder, for example:

Code:

class FlagHolder {
   Set<SessionImplementor> allowedSessions;

   public static boolean isLazyInitAllowed(SessionImplementor session) {
       return allowedSessions.contains(session);
   }
}

Yes, I would like to associate this type of checking with particular sessions, not with my application context for example. And at this level I don't want to check if the session is connected, if not HibernateException will be thrown later.
I could, of course, hold my own session reference inside my objects, but why should I do this if Hibernate does this for me?

max · **Posted:** Tue May 09, 2006 9:04 am

your code should not assume any thing about a session being attached to the objects.

btw. how did you get the collection without having the root/parent object?

plas · **Joined:** Fri May 05, 2006 11:15 am **Posts:** 6

max wrote:

btw. how did you get the collection without having the root/parent object?

I have parent object, as the mechanism I'm trying to develop is in fact nested inside the getter of some child, so access to parent is available. However, I cannot assume that my parent class is instanceof HibernateProxy (because session.list() for example returns such beings that are not proxied instances, but could have uninitialised persistent collections).