I've got a one-to-many relationship and every time I try to access the collection I get "org.hibernate.LazyInitializationException failed to lazily initialize a collection of role: ... no session or session was closed". The trick is that session IS open. I use ServletFilter to handle session management and have explicitly checked the state of the session anyway.

Here is the piece of code which throws the exception:




Hibernate version:
Hibernate 3.1

Mapping documents:
<class name="Cycle" table="cycle">
<cache usage="read-write"/>
<id name="id">
<generator class="native"/>
</id>
<set name="nominations" table="nomination" cascade="all-delete-orphan" inverse="true" lazy="true">
<cache usage="read-write"/>
<key column="cycle_id" not-null="true"/>
<one-to-many class="Nomination"/>
</set>
</class>

<class name="Nomination" table="nomination" lazy="true">
<cache usage="read-write"/>
<id name="id"><generator class="native"/></id>
<many-to-one name="cycle" column="cycle_id" cascade="none" not-null="true"></many-to-one>
</class>


Full stack trace of any exception that occurs:
[13/02/06 12:04:11:152 EST] 2f03744f LazyInitializ E org.hibernate.LazyInitializationException failed to lazily initialize a collection of role: Cycle.nominations, no session or session was closed

[13/02/06 12:04:11:167 EST] 2f03744f LazyInitializ E org.hibernate.LazyInitializationException TRAS0014I: The following exception was logged org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: Cycle.nominations, no session or session was closed
at org.hibernate.collection.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:358)
at org.hibernate.collection.AbstractPersistentCollection.throwLazyInitializationExceptionIfNotConnected(AbstractPersistentCollection.java:350)
at org.hibernate.collection.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:343)
at org.hibernate.collection.AbstractPersistentCollection.write(AbstractPersistentCollection.java:183)
at org.hibernate.collection.PersistentSet.add(PersistentSet.java:165)
at Cycle.addNomination(Cycle.java:94)
...

It looks like the session that loaded this.nominations isn't the session that's being returned from Init.getSessionFactory().getCurrentSession(). Can you check that? If you find that that's the case, find out where that session is being closed, and don't close it. Alternatively, you could put this.nominations in the current session, using Init.getSessionFactory().getCurrentSession().lock(this.nominations, LockMode.NONE);

Also, check the value of
hibernate.transaction.auto_close_session
since Hibernate 3.1 introduces Contextual Sessions and Session closing depends on what type of contextual session has been chosen for the application. Refer to section 2.5 of the Reference manual.
If you dont specify any for the context_class, jta is taken as the default and if you had closen your transaction anytime after you retrieved the first set of results, the session would have gotten closed as the JTA Transaction is closed.

Yes! Stupid, I was "caching" reference to a Cycle object in a static variable. Of course it would be the different session.

Thank you!