This is very strange. Let me explain the scenario and you can tell me if we have something fundamentally wrong.

We have a class (Persister) that receives a lightweight object (VO) to persist, the Persister does the following:

1. Starts a hibernate transaction

2. Creates hibernate pojo’s and calls session.save(persister_created_pojo) on each of the pojo’s

3. Passes these objects to Drools, which creates more hibernate pojo’s and returns them

4. The Persister class then calls session.save(drools_created_pojo) for each of the returned pojo’s

5. If no errors exist the transaction is committed, otherwise it is rolled back.

When we updated the drules packages from 4.0.0 to 4.0.1 we started getting these errors, it seems like the session gets

disconnected the moment we pass the pojo to drools.

Maybe someone has some advice or has encountered something similar.

Juan

From: rules-users-bounces@lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Mark Proctor
Sent: 27 September 2007 04:12 PM
To: Rules Users List
Cc: juan.heyns@epiuse.com
Subject: Re: [rules-users] Hibernate

Drools doesn't handle Hibernate in anyway, we have no awareness of it. The exceptions indicates that you have lazy loading enabled for hibernate, but your session is disconnected when it tries to lazy load the object.

Mark
Heyns, Juan wrote:

Hi,

I am getting the following error with 4.0.1, I didn’t get this with 4.0.0… Has anything changed in the way Drools works with Hibernate.

Juan

15:24:52,281 ERROR LazyInitializationException:19 - failed to lazily initialize a collection, no session or session was closed

org.hibernate.LazyInitializationException: failed to lazily initialize a collection, 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.readElementExistence(AbstractPersistentCollection.java:132)

at org.hibernate.collection.PersistentSet.contains(PersistentSet.java:153)

at org.drools.base.evaluators.ObjectFactory$ObjectContainsEvaluator.evaluateCachedLeft(ObjectFactory.java:481)

at org.drools.rule.VariableRestriction.isAllowedCachedLeft(VariableRestriction.java:72)

at org.drools.rule.VariableConstraint.isAllowedCachedLeft(VariableConstraint.java:72)

at org.drools.common.SingleBetaConstraints.isAllowedCachedLeft(SingleBetaConstraints.java:117)

at org.drools.reteoo.JoinNode.assertTuple(JoinNode.java:119)

at org.drools.reteoo.CompositeTupleSinkAdapter.createAndPropagateAssertTuple(CompositeTupleSinkAdapter.java:73)

at org.drools.reteoo.LeftInputAdapterNode.assertObject(LeftInputAdapterNode.java:131)

at org.drools.reteoo.SingleObjectSinkAdapter.propagateAssertObject(SingleObjectSinkAdapter.java:20)

at org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:160)

at org.drools.reteoo.Rete.assertObject(Rete.java:176)

at org.drools.reteoo.ReteooRuleBase.assertObject(ReteooRuleBase.java:196)

at org.drools.reteoo.ReteooWorkingMemory.doInsert(ReteooWorkingMemory.java:70)

at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:854)

at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:826)

at org.drools.base.DefaultKnowledgeHelper.insert(DefaultKnowledgeHelper.java:60)

at org.drools.base.DefaultKnowledgeHelper.insert(DefaultKnowledgeHelper.java:54)

at com.lonmin.bns.domain.rules.Rule_Stope_Drilling_work_is_evaluated_based_on_the_holes_drilled_and_blasts_0.consequence(Rule_Stope_Drilling_work_is_evaluated_based_on_the_holes_drilled_and_blasts_0.java:35)

at com.lonmin.bns.domain.rules.Rule_Stope_Drilling_work_is_evaluated_based_on_the_holes_drilled_and_blasts_0ConsequenceInvoker.evaluate(Rule_Stope_Drilling_work_is_evaluated_based_on_the_holes_drilled_and_blasts_0ConsequenceInvoker.java:22)

at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:550)

at org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:514)

at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:434)

at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:396)

at com.lonmin.bns.domain.rules.RulesEngine.calculateStopeDrillingBonus(RulesEngine.java:54)

at com.lonmin.bns.domain.model.StopeDrillingCardPersister.processDetail(StopeDrillingCardPersister.java:371)

at com.lonmin.bns.domain.model.StopeDrillingCardPersister.processCard(StopeDrillingCardPersister.java:276)

at com.lonmin.bns.domain.model.StopeDrillingCardPersister.process(StopeDrillingCardPersister.java:69)

at com.lonmin.bns.domain.model.ValueObjectPersister.persist(ValueObjectPersister.java:38)

at com.lonmin.bns.domain.model.StopeDrillingCardPersisterTest.testEditStopeDrillingCard(StopeDrillingCardPersisterTest.java:182)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

at java.lang.reflect.Method.invoke(Method.java:324)

at junit.framework.TestCase.runTest(TestCase.java:164)

at junit.framework.TestCase.runBare(TestCase.java:130)

at junit.framework.TestResult$1.protect(TestResult.java:106)

at junit.framework.TestResult.runProtected(TestResult.java:124)

at junit.framework.TestResult.run(TestResult.java:109)

at junit.framework.TestCase.run(TestCase.java:120)

at junit.framework.TestSuite.runTest(TestSuite.java:230)

at junit.framework.TestSuite.run(TestSuite.java:225)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:392)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:276)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:167)