failed to lazily initialize a collection of role

[triathlon98]

I have the error below which happens during a call to e EJB3 SFSB. There is no explicit rollback happening in the code and the session is (obviously) managed by the container. I am using JBoss 4.0.4GA.

2006-07-17 06:02:05,374 ERROR [org.hibernate.LazyInitializationException] failed to lazily initialize a collection of role: org.ictrace.server.pm.DMWeightGroupTotalBean.batches, no session or session was closed
org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: org.ictrace.server.pm.DMWeightGroupTotalBean.batches, 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.read(AbstractPersistentCollection.java:86) at org.hibernate.collection.PersistentBag.iterator(PersistentBag.java:246) at package.WeightMediatorBaseEx.addWGTBatch(WeightMediatorBaseEx.java:359) at ...

The code where the exception is invoced looks like this :

 private void addWGTBatch( DMWeightGroupTotalBean obj, String batchRef )
 throws UnidConstraintViolation
 {
 if ( obj == null || batchRef == null ) return;
 try
 {
 Collection<DMWeightGroupTotal_BatchesBean> batches = obj.getBatches();
 if ( batches == null )
 {
 batches = new ArrayList<DMWeightGroupTotal_BatchesBean>();
 obj.setBatches( batches );
 }
 // check if the object already exists
 for ( DMWeightGroupTotal_BatchesBean bb : batches ) // error is reported on this line
 {
 if ( batchRef.equals( bb.getBatches() ) ) return;
 }
 batches.add( new DMWeightGroupTotal_BatchesBean( batchRef ) );
 obj.modified();
 }
 catch ( Exception ex )
 {
 throw new UnidConstraintViolation( UCV_PROBLEM_WHEN_ADDING_BATCH_TO_THE_TOTAL_LINE, batchRef, ex );
 }
 }

Does anybody have any idea what is causing this error and how I can fix / work around it?

Thanks,
Joachim

[scraatz]

It seems that your batches are lazyly loaded. Therefore you can call getBatches() only within the same Transaction that loaded obj.
You could mark the one-to-many relation as EAGER-loaded or use an extended Entitymanager.

Stefan

[triathlon98]

That is just it. Everything is happening inside the same tx. The SFSB starts by initialising the entity bean and does the operations on it. Somewhere during this process something goes wrong and this error occurs.

Strangely enough, this code was working just fine when I was using 4.0.4CR1 with a ealier EJB3 release...

Joachim

[scraatz]

What kind of entity manager do you used. There where changes in the handling of entity managers...

[triathlon98]

The entitymanager is declared using

@PersistenceContext private EntityManager entityManager;

and is automatically injected.