Proxy and Query

nvolpini · **Posted:** Fri Nov 21, 2003 7:20 pm

session = fac.openSession();
Query q = new Query("from MyClassWithProxy ...");
session.close();

Iterator it = q.iterate();
while (it.hasNext()) {
MyClassWithProxy c = (MyClassWithProxy) it.next();
c.getAtribute() ///// Exception initializing proxy .. net.sf.hibernate.HibernateException: Could not initialize proxy (session closed)
}

If my class doesn't use a proxy I can iterate the results without problem even after close the session, otherwise if my class uses a proxy the class will be loaded only when I call an accessor method, in this case during the iteration but my session is closed ...

Its possible to initialize the class with proxy before start to iterate it ?

emmanuel · **Posted:** Fri Nov 21, 2003 8:03 pm

Are you sure, non proxied class works ?
Since Hibernate requests DB for each line when using iiterate (and object no in session or jvm cache), I'm skeptical.

nvolpini · **Posted:** Fri Nov 21, 2003 8:14 pm

Yes, it works ...

Code:

Session session = null;
        try {
            session = factory.openSession();

            query = session.createQuery("from Empresa as e where :user not in elements (e.users) ");
            query.setParameter("user",model,Hibernate.entity(com.estobel.model.User.class));

                    
        } catch (HibernateException e) {
            reporter.showErrorMessage("Erro: "+e);
            return;

        } finally {
            session.close();
        }

//Here I Iterate ... works fine when Empresa isn't proxied.

emmanuel · **Posted:** Fri Nov 21, 2003 8:38 pm

You're telling me that

open session
create query
close session
execute query

works, there is something I missed : I must go to bed.

Code:

try {
            session = factory.openSession();
            query = session.createQuery("from Empresa as e where :user not in elements (e.users) ");
           query.setParameter("user",model,Hibernate.entity(com.estobel.model.User.class));                   
        } catch (HibernateException e) {
            reporter.showErrorMessage("Erro: "+e);
            return;
        } finally {
            session.close();
        }
        terator it = q.iterate();  //no error here ???
        while (it.hasNext()) {

dimas · **Posted:** Fri Nov 21, 2003 9:00 pm

nvolpini, Emmanuel is right - the code you show here can not work even if you were not using proxies because you close session before Hibernate is able to perform the first SELECT. Obviously, you are showing us not the real code but some fragments of it (I suppose manually typed here). For example, Query is INTERFACE but you managed to compile "new Query(...)" somehow... If you prefer you problem was solved quickly, your better show the real code which actually fails isntead of some "transcript". (No offence, this is just my personal expirience)

Anyway. About your question: docs says: "Note that find() does not return proxies.". I suppose if you use session.find() instead of iterate(), everything should work fine. But make sure, you calling find() BEFORE you close session.

nvolpini · **Posted:** Fri Nov 21, 2003 10:01 pm

Something is wrong with my code ... help to understand the log for:

Code:

Session session = null;
        try {
            session = factory.openSession();

            query = session.createQuery("from Empresa as e where :user not in elements (e.users) ");
            query.setParameter("user",model,Hibernate.entity(com.estobel.model.User.class));

                    
        } catch (HibernateException e) {
            reporter.showErrorMessage("Erro: "+e);
            return;

        } finally {
            factory.closeSession(session);
        }

java.util.Iterator it = query.iterate();

while (it.hasNext()) {
   Group obj = (Group) it.next();
    ....
}

The log for the code ...

[code]
23:31:38,977 DEBUG HibernateFactory:? - Abrindo sess

dimas · **Posted:** Sat Nov 22, 2003 4:43 am

Hm... I see no errors in your log.

emmanuel · **Posted:** Sat Nov 22, 2003 9:50 am

The request executed is

Code:

from Group as e where :user not in elements (e.users)

not

Code:

from Empresa as e where :user not in elements (e.users)

Thus

Code:

query = session.createQuery("from Empresa as e where :user not in elements (e.users) "); 

is never executed.

try to replace HibernateException with Exception in your catch statement