java.lang.NullPointerException on onPreRemoveCollection of A

[francescods]

Hi all,

I get this exception when trying to replicate an object in a synchronized database:

DEBUG [main] (CodeSystemDAOHibernate.java:131) - java.lang.NullPointerException
 at org.hibernate.envers.event.AuditEventListener.onPreRemoveCollection(AuditEventListener.java:235)
 at org.hibernate.action.CollectionRemoveAction.preRemove(CollectionRemoveAction.java:134)
 at org.hibernate.action.CollectionRemoveAction.execute(CollectionRemoveAction.java:100)
 at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:279)
 at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:263)
 at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:169)
 at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
 at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50)
 at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1027)
 at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:365)
 at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:137)
 at com.phi.dictionarymanager.logic.hibernate.GenericDAOHibaernate.commitNetwork(GenericDAOHibaernate.java:183)
 at com.phi.dictionarymanager.logic.hibernate.CodeSystemDAOHibernate.save(CodeSystemDAOHibernate.java:92)
 at com.phi.dictionarymanager.ui.widgets.VocabolaryItemNewComposite.save(VocabolaryItemNewComposite.java:515)
 at com.phi.dictionarymanager.ui.widgets.VocabularyDomainsNavigatorComposite$18.handleEvent(VocabularyDomainsNavigatorComposite.java:1434)
 at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:66)
 at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:938)
 at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3682)
 at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3293)
 at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2389)
 at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2353)
 at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2219)
 at org.eclipse.ui.internal.Workbench$4.run(Workbench.java:466)
 at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:289)
 at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:461)
 at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
 at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:106)
 at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:169)
 at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:106)
 at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:76)
 at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:363)
 at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:176)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
 at java.lang.reflect.Method.invoke(Unknown Source)
 at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:508)
 at org.eclipse.equinox.launcher.Main.basicRun(Main.java:447)
 at org.eclipse.equinox.launcher.Main.run(Main.java:1173)
 at org.eclipse.equinox.launcher.Main.main(Main.java:1148)

Code throwing the exception:

beginTransactionLocal();
makePersistentLocal(cs);
commitLocal();
closeSessionLocal();

beginTransactionNetwork();
makePersistentNetwork(cs);
commitNetwork();
closeSessionNetwork();

For this insertion of the object cs, the makePersistentLocal makes a saveOrUpdate call, while makePersistentNetwork calls replicate(cs, ReplicateMode.LATEST_VERSION).

My hibernate-mysql.cfg.xml and hibernate-hsql.cfg.xml are very similar (I post only the mysql one):

<hibernate-configuration>
 <session-factory>
 ...
 <property name="org.hibernate.envers.revisionOnCollectionChange">true</property>
 <property name="org.hibernate.envers.doNotAuditOptimisticLockingField">true</property>


 <!-- HIBERNATE BEAN MAPPINGS -->
 <mapping resource="com/phi/dictionarymanager/beans/CodeEquivalent.hbm.xml" />
 <mapping resource="com/phi/dictionarymanager/beans/CodeValue.hbm.xml" />
 <mapping resource="com/phi/dictionarymanager/beans/CodeTranslation.hbm.xml" />
 <mapping resource="com/phi/dictionarymanager/beans/CodeSystem.hbm.xml" />


 <event type="post-insert">
 <listener class="org.hibernate.envers.event.AuditEventListener" />
 </event>
 <event type="post-update">
 <listener class="org.hibernate.envers.event.AuditEventListener" />
 </event>
 <event type="post-delete">
 <listener class="org.hibernate.envers.event.AuditEventListener" />
 </event>
 <event type="pre-collection-update">
 <listener class="org.hibernate.envers.event.AuditEventListener" />
 </event>
 <event type="pre-collection-remove">
 <listener class="org.hibernate.envers.event.AuditEventListener" />
 </event>
 <event type="post-collection-recreate">
 <listener class="org.hibernate.envers.event.AuditEventListener" />
 </event>


 </session-factory>
</hibernate-configuration>

All the collections in this project are in mode lazy="true".

Do someone of you know what kind of problem is this?

Thank you in advance,
Francesco.

[francescods]

I forgot to say that the first saving is ok and the onPreRemoveCollection method is never called..

[adamw]

Hello,

it's hard to say ... could you create a JIRA issue with a testcase?
The NPE happens on the following statement:

collectionEntry.getLoadedPersister().isInverse()

and neither the collectionEntry or the persister should be null, so sth weird is happening :)

Adam

[francescods]

Hi Adam,

thank youfor having answered so soon.
The key number of the envers issue is HHH-3847 (http://opensource.atlassian.com/projects/hibernate/browse/HHH-3847).

I hope it can be solved.
Thanks again,

Francesco.

[heyho]

Hello,

above mentioned exception also occurs in following scenario:

Entity A has many-to-many relationship to Entity B

A a = new A()
Set setOfB = new HashSet<B>();
setOfB.add(new B());
a.setB(setOfB);
save(a);
a.setB(new Hashset<B>()); // clear set of B in A
update(a);

following version works though:

A a = new A()
Set setOfB = new HashSet<B>();
setOfB.add(new B());
a.setB(setOfB);
save(a);
a.getB().clear; // clear set of B in A
update(a);

Regards

[adamw]

That's weird, I'll try to reproduce and, hopefully, fix. Thanks for the code snippet! :)

Ada,