Hi,

I get the exception below when calling query.list() for the following query:

"from Customer"

A test case has already been posted to Jira about a year ago: http://opensource.atlassian.com/project ... e/HHH-2624

For me, it is very hard to reproduce - it happends maybe twice per day. We use second level cache but no query cache.

Any insight into this problems/workarounds?

---

java.lang.NullPointerException

at org.hibernate.persister.entity.AbstractEntityPersister.loadByUniqueKey(AbstractEntityPersister.java:1649)

at org.hibernate.type.EntityType.loadByUniqueKey(EntityType.java:608)

at org.hibernate.type.EntityType.resolve(EntityType.java:382)

at org.hibernate.type.EntityType.nullSafeGet(EntityType.java:204)

at org.hibernate.persister.collection.AbstractCollectionPersister.readElement(AbstractCollectionPersister.java:703)

at org.hibernate.collection.PersistentSet.readFrom(PersistentSet.java:318)

at org.hibernate.loader.Loader.readCollectionElement(Loader.java:1008)

at org.hibernate.loader.Loader.readCollectionElements(Loader.java:646)

at org.hibernate.loader.Loader.getRowFromResultSet(Loader.java:591)

at org.hibernate.loader.Loader.doQuery(Loader.java:701)

at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:236)

at org.hibernate.loader.Loader.loadCollectionBatch(Loader.java:2032)

at org.hibernate.loader.collection.BatchingCollectionInitializer.initialize(BatchingCollectionInitializer.java:47)

at org.hibernate.persister.collection.AbstractCollectionPersister.initialize(AbstractCollectionPersister.java:565)

at org.hibernate.event.def.DefaultInitializeCollectionEventListener.onInitializeCollection(DefaultInitializeCollectionEventListener.java:63)

at org.hibernate.impl.SessionImpl.initializeCollection(SessionImpl.java:1716)

at org.hibernate.collection.AbstractPersistentCollection.forceInitialization(AbstractPersistentCollection.java:454)

at org.hibernate.engine.StatefulPersistenceContext.initializeNonLazyCollections(StatefulPersistenceContext.java:844)

at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:241)

at org.hibernate.loader.Loader.doList(Loader.java:2213)

at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2104)

at org.hibernate.loader.Loader.list(Loader.java:2099)

at org.hibernate.hql.classic.QueryTranslatorImpl.list(QueryTranslatorImpl.java:912)

at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:172)

at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1121)

at org.hibernate.impl.QueryImpl.list(QueryImpl.java:79)

I just verified that this only happends when using the second-level cache.

Sequence to reproduce:

1. Run query "from Customer"

2. Add an entry to Customer#products collection

3. Run query "from Customer" => nullpointerexception in query.list()


This happends everytime, but only with second-level cache (OSCache).

It should be noted that there is extensive use of "property-ref" relations, even in collections.

Could that cause the second-level cache to fail?

I also see from the debug output that "Cached item was locked" happends a lot, could this be the root of the problem?

Thanks in advance for any help!

Still haven't found a viable work-around :-(

Any ideas folks?