Hello, I have written a initialize collections method in the generic DAO for I can invoke since view layer through ManagedBean. I use Spring 3 and JSF2, the DAOs extends HibernateDAOSupport and I use getHibernate of this class for to work with database. Many collections are lazy and my idea is to initialize this collections with unique method and not having to writte a specific method for class/object.


This is the code:



I have checked that the session is open, but throw this exception: ERROR [org.hibernate.LazyInitializationException] (http-localhost-127.0.0.1-8080-3) failed to lazily initialize a collection of role: org.pfc.modelo.Asociacion.miembros, no session or session was closed: org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: org.pfc.modelo.Asociacion.miembros, no session or session was closed

why occurs this behavior? it is correct??

Kind regards.

Hi Parche,

every persistent collection has a internal reference to a hibernate session
which corresponds to the session in which the owner entity was read.
If that session is already closed when you initialize the collection, then the LazyInitializationException raises.

In you code you seem to assume, that the collections should use something like SessionFactory().getCurrentSession
for initializations but that isn't the case.
You must force the collections to use your session, instead to the memorized one, like following:



This works fine for read-only purposes. Changes to your collections will not be persisted to database.

Thank for your response, I have tried your code but the method setCurrentSession(Session session) is not validate,it is necesary SessionImplementor) I have modified the code,but my code not work:



I use Hibernate 3.5.6.

Trace error is the same:

ERROR [org.hibernate.LazyInitializationException] (http-localhost-127.0.0.1-8080-3) failed to lazily initialize a collection of role: org.pfc.modelo.Asociacion.miembros, no session or session was closed: org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: org.pfc.modelo.Asociacion.miembros, no session or session was closed

Any suggestions?

Regards.

edit:

I have tried to invoke setCurrentSession with StatelessSession,AbstractSession and Session with this paramert not work because this method need how argument their respective implementations.

Sorry I was wrong,
to me it works, when attaching the collections-owner to the persistent context first, see code below.
N.B.: I use Hiberante 3.6

Great solution¡ This code saving time and improving efficiency in the app. Can you tell me in that book or reference exists information about this? Thank you very much for your response.

Kinds regards.

I fear there's no book containing this information (at least book "Java Persistence with Java" does'nt).
I found this solution by looking at the exception stacktrace and looking the code of Hibernate.

One more time....Fantastic work'¡¡ Thanks.


Regards.