Hi,
I am getting a NullPointerException and don't know why!
The data is a DATA object with a list of properties (PROPERTY) (@OneToMany)!
First persisting the DATA --> works fine
I detach the DATA Element and set a new PROPERTY object
merging the DATA of the data --> works fine
I do the same again detaching the object and set a new PROPERTY object
merging the DATA --> NullPointerException?!
Why, what is different, why doesn't it work the second time?
I am happy for any hint...
If you need further information I am happy to provide them...
Thanks
Marcel
If I have a look in code of the "CollectionContainerPolicy.iteratorFor" the method tries to return an iterator and apparently the object has a null value, but why?
Here is the stack trace...
Merge Data
[TopLink Finer]: 2007.08.06 02:40:08.421--ServerSession(6597453)--Thread(Thread[AWT-EventQueue-0,6,main])--client acquired
[TopLink Finest]: 2007.08.06 02:40:08.421--UnitOfWork(20238918)--Thread(Thread[AWT-EventQueue-0,6,main])--Merge clone with references Data
Caught Exception: null
java.lang.NullPointerException
at oracle.toplink.essentials.internal.queryframework.CollectionContainerPolicy.iteratorFor(CollectionContainerPolicy.java:172)
at oracle.toplink.essentials.internal.helper.WriteLockManager.traverseRelatedLocks(WriteLockManager.java:171)
at oracle.toplink.essentials.internal.helper.WriteLockManager.acquireLockAndRelatedLocks(WriteLockManager.java:149)
at oracle.toplink.essentials.internal.helper.WriteLockManager.checkAndLockObject(WriteLockManager.java:378)
at oracle.toplink.essentials.internal.helper.WriteLockManager.traverseRelatedLocks(WriteLockManager.java:186)
at oracle.toplink.essentials.internal.helper.WriteLockManager.acquireLockAndRelatedLocks(WriteLockManager.java:149)
at oracle.toplink.essentials.internal.helper.WriteLockManager.acquireLocksForClone(WriteLockManager.java:89)
at oracle.toplink.essentials.internal.sessions.UnitOfWorkImpl.cloneAndRegisterObject(UnitOfWorkImpl.java:669)
at oracle.toplink.essentials.internal.sessions.UnitOfWorkIdentityMapAccessor.getAndCloneCacheKeyFromParent(UnitOfWorkIdentityMapAccessor.java:167)
at oracle.toplink.essentials.internal.sessions.UnitOfWorkIdentityMapAccessor.getFromIdentityMap(UnitOfWorkIdentityMapAccessor.java:105)
at oracle.toplink.essentials.internal.sessions.IdentityMapAccessor.getFromIdentityMap(IdentityMapAccessor.java:310)
at oracle.toplink.essentials.internal.sessions.MergeManager.registerObjectForMergeCloneIntoWorkingCopy(MergeManager.java:674)
at oracle.toplink.essentials.internal.sessions.MergeManager.mergeChangesOfCloneIntoWorkingCopy(MergeManager.java:411)
at oracle.toplink.essentials.internal.sessions.MergeManager.mergeChanges(MergeManager.java:264)
at oracle.toplink.essentials.internal.sessions.UnitOfWorkImpl.mergeCloneWithReferences(UnitOfWorkImpl.java:2723)
at oracle.toplink.essentials.internal.ejb.cmp3.base.RepeatableWriteUnitOfWork.mergeCloneWithReferences(RepeatableWriteUnitOfWork.java:219)
at oracle.toplink.essentials.internal.ejb.cmp3.base.EntityManagerImpl.mergeInternal(EntityManagerImpl.java:235)
at oracle.toplink.essentials.internal.ejb.cmp3.EntityManagerImpl.merge(EntityManagerImpl.java:128)
at MainProgramManagement.ProgramMain.mergeData(ProgramMain.java:846)
at MainProgramManagement.PersistenceDBManager.saveDataToDB(PersistenceDBManager.java:552)
at
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