Bug 745768

Would it be possible to add a pom.xml file or all libraries in future reproducer attachments? The missing libraries make it hard to reproduce.

With drools 5.4.0-SNAPSHOT I am getting this:

{code}
Exception in thread "main" [Error: unable to resolve method: org.jboss.qa.brms.persistencequery.Fact.name__() [arglength=0]]
[Near : {... name == name__ ....}]
             ^
[Line: 1, Column: 1]
	at org.mvel2.optimizers.impl.refl.ReflectiveAccessorOptimizer.getMethod(ReflectiveAccessorOptimizer.java:1068)
	at org.mvel2.optimizers.impl.refl.ReflectiveAccessorOptimizer.getMethod(ReflectiveAccessorOptimizer.java:982)
	at org.mvel2.optimizers.impl.refl.ReflectiveAccessorOptimizer.getBeanProperty(ReflectiveAccessorOptimizer.java:677)
	at org.mvel2.optimizers.impl.refl.ReflectiveAccessorOptimizer.getBeanPropertyAO(ReflectiveAccessorOptimizer.java:474)
	at org.mvel2.optimizers.impl.refl.ReflectiveAccessorOptimizer.compileGetChain(ReflectiveAccessorOptimizer.java:372)
	at org.mvel2.optimizers.impl.refl.ReflectiveAccessorOptimizer.optimizeAccessor(ReflectiveAccessorOptimizer.java:141)
	at org.mvel2.optimizers.dynamic.DynamicOptimizer.optimizeAccessor(DynamicOptimizer.java:67)
	at org.mvel2.ast.ASTNode.optimize(ASTNode.java:157)
	at org.mvel2.ast.ASTNode.getReducedValueAccelerated(ASTNode.java:113)
	at org.mvel2.ast.BinaryOperation.getReducedValueAccelerated(BinaryOperation.java:116)
	at org.mvel2.compiler.ExecutableAccessor.getValue(ExecutableAccessor.java:42)
	at org.mvel2.MVEL.executeExpression(MVEL.java:922)
	at org.drools.rule.constraint.MvelConditionEvaluator.evaluate(MvelConditionEvaluator.java:34)
	at org.drools.rule.constraint.MvelConditionEvaluator.evaluate(MvelConditionEvaluator.java:30)
	at org.drools.rule.constraint.MvelConstraint.evaluate(MvelConstraint.java:132)
	at org.drools.rule.constraint.MvelConstraint.isAllowedCachedLeft(MvelConstraint.java:101)
	at org.drools.common.DoubleNonIndexSkipBetaConstraints.isAllowedCachedLeft(DoubleNonIndexSkipBetaConstraints.java:136)
	at org.drools.reteoo.JoinNode.assertLeftTuple(JoinNode.java:103)
	at org.drools.reteoo.CompositeLeftTupleSinkAdapter.doPropagateAssertLeftTuple(CompositeLeftTupleSinkAdapter.java:232)
	at org.drools.reteoo.CompositeLeftTupleSinkAdapter.createAndPropagateAssertLeftTuple(CompositeLeftTupleSinkAdapter.java:118)
	at org.drools.reteoo.LeftInputAdapterNode.assertObject(LeftInputAdapterNode.java:158)
	at org.drools.reteoo.SingleObjectSinkAdapter.propagateAssertObject(SingleObjectSinkAdapter.java:59)
	at org.drools.reteoo.AlphaNode.assertObject(AlphaNode.java:134)
	at org.drools.reteoo.SingleObjectSinkAdapter.propagateAssertObject(SingleObjectSinkAdapter.java:59)
	at org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:211)
	at org.drools.reteoo.EntryPointNode.assertQuery(EntryPointNode.java:146)
	at org.drools.reteoo.ReteooWorkingMemory.getQueryResults(ReteooWorkingMemory.java:195)
	at org.drools.impl.StatefulKnowledgeSessionImpl.getQueryResults(StatefulKnowledgeSessionImpl.java:770)
	at org.drools.command.runtime.rule.QueryCommand.execute(QueryCommand.java:105)
	at org.drools.command.runtime.rule.QueryCommand.execute(QueryCommand.java:37)
	at org.drools.command.runtime.BatchExecutionCommandImpl.execute(BatchExecutionCommandImpl.java:155)
	at org.drools.command.runtime.BatchExecutionCommandImpl.execute(BatchExecutionCommandImpl.java:76)
	at org.drools.command.impl.DefaultCommandService.execute(DefaultCommandService.java:36)
	at org.drools.persistence.SingleSessionCommandService.execute(SingleSessionCommandService.java:358)
	at org.drools.command.impl.CommandBasedStatefulKnowledgeSession.execute(CommandBasedStatefulKnowledgeSession.java:482)
	at org.jboss.qa.brms.persistencequery.PersistenceQueryTest.main(PersistenceQueryTest.java:46)
{code}

In drools 5.3.2-SNAPSHOT I am also getting the NPE. The ReflectiveAccessorOptimizer stacktrace might be a different regression in 5.4 related to the MVEL optimization work.

It looks like the ruleset.drl is invalid.

Instead of
  follows( $middle, next; )
it should be
  ?follows( $middle, next; )

Changing that does not prevent the NPE in 5.3. It probably fixes the ReflectiveAccessorOptimizer in 5.4 (causing an NPE there too?).

This has nothing to do with the backwards chaining query.
I reproduced it with 
  commands.add(CommandFactory.newSetGlobal("foobar", "boe", true));
with drools 5.4.0-SNAPSHOT.

The problem is the use of
  JPAKnowledgeService.newStatefulKnowledgeSession(kbase, ksconf, env)
Replacing that by
  kbase.newStatefulKnowledgeSession();
stops the issue from occurring.

I recreated a testcase inside drools-persistence-jpa which only uses SetGlobalCommand:

org.drools.persistence.map.impl.JpaBasedPersistenceTest#testSetGlobalWithJPAKnowledgeService

It's @Ignored atm.

The issue is fixed.

    Technical note added. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    New Contents:
When trying to execute BatchExecutionCommaind on a persisted StatefulKnowledgeSession a Null Pointer Exception is thrown.

    Technical note updated. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    Diffed Contents:
@@ -1 +1 @@
-When trying to execute BatchExecutionCommaind on a persisted StatefulKnowledgeSession a Null Pointer Exception is thrown.+When trying to execute BatchExecutionCommand on a persisted StatefulKnowledgeSession a Null Pointer Exception was thrown. The issue has been resolved by replacing the  JPAKnowledgeService.newStatefulKnowledgeSession(kbase, ksconf, env) method, with the kbase.newStatefulKnowledgeSession() method.