<span style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">Hello all,</span><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">
<br></div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">I have an application that was written originally using Drools 5.3.1.Final that works just fine. I wrote a JUnit test that runs through values contained in a spreadsheet. Everything was working great. I updated the application to use Drools 5.4.0.Final and then the test stopped working. I have debugged the code and here is the exception thrown:</div>
<div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif"><br></div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">
<div>Exception executing consequence for rule "create vcmax" in org.zoikks.drools: java.lang.NullPointerException</div><div><span style="white-space:pre-wrap"> </span>at org.drools.runtime.rule.impl.DefaultConsequenceExceptionHandler.handleException(DefaultConsequenceExceptionHandler.java:39)</div>
<div><span style="white-space:pre-wrap"> </span>at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1283)</div><div><span style="white-space:pre-wrap"> </span>at org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:1209)</div>
<div><span style="white-space:pre-wrap"> </span>at org.drools.common.DefaultAgenda.fireAllRules(DefaultAgenda.java:1442)</div><div><span style="white-space:pre-wrap"> </span>at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:710)</div>
<div><span style="white-space:pre-wrap"> </span>at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:674)</div><div><span style="white-space:pre-wrap"> </span>at org.drools.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:230)</div>
<div><span style="white-space:pre-wrap"> </span>at org.zoikks.drools.xlsx.SampleWorkflowXlsx.check(SampleWorkflowXlsx.java:103)</div><div><span style="white-space:pre-wrap"> </span>at org.zoikks.drools.xlsx.SampleWorkflowXlsx.testSampleXlsxSheets(SampleWorkflowXlsx.java:77)</div>
<div><span style="white-space:pre-wrap"> </span>at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)</div><div><span style="white-space:pre-wrap"> </span>at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)</div>
<div><span style="white-space:pre-wrap"> </span>at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)</div><div><span style="white-space:pre-wrap"> </span>at java.lang.reflect.Method.invoke(Method.java:601)</div>
<div><span style="white-space:pre-wrap"> </span>at junit.framework.TestCase.runTest(TestCase.java:168)</div><div><span style="white-space:pre-wrap"> </span>at junit.framework.TestCase.runBare(TestCase.java:134)</div><div>
<span style="white-space:pre-wrap"> </span>at junit.framework.TestResult$1.protect(TestResult.java:110)</div><div><span style="white-space:pre-wrap"> </span>at junit.framework.TestResult.runProtected(TestResult.java:128)</div>
<div><span style="white-space:pre-wrap"> </span>at junit.framework.TestResult.run(TestResult.java:113)</div><div><span style="white-space:pre-wrap"> </span>at junit.framework.TestCase.run(TestCase.java:124)</div><div><span style="white-space:pre-wrap"> </span>at junit.framework.TestSuite.runTest(TestSuite.java:243)</div>
<div><span style="white-space:pre-wrap"> </span>at junit.framework.TestSuite.run(TestSuite.java:238)</div><div><span style="white-space:pre-wrap"> </span>at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:83)</div>
<div><span style="white-space:pre-wrap"> </span>at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)</div><div><span style="white-space:pre-wrap"> </span>at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)</div>
<div><span style="white-space:pre-wrap"> </span>at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)</div><div><span style="white-space:pre-wrap"> </span>at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)</div>
<div><span style="white-space:pre-wrap"> </span>at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)</div><div><span style="white-space:pre-wrap"> </span>at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)</div>
<div>Caused by: java.lang.NullPointerException</div><div><span style="white-space:pre-wrap"> </span>at ConditionEvaluator0f64b1c63942476d80eb29d1cdffda28.evaluate(Unknown Source)</div><div><span style="white-space:pre-wrap"> </span>at org.drools.rule.constraint.MvelConstraint.evaluate(MvelConstraint.java:167)</div>
<div><span style="white-space:pre-wrap"> </span>at org.drools.rule.constraint.MvelConstraint.isAllowed(MvelConstraint.java:124)</div><div><span style="white-space:pre-wrap"> </span>at org.drools.reteoo.AlphaNode.assertObject(AlphaNode.java:137)</div>
<div><span style="white-space:pre-wrap"> </span>at org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateAssertObject(CompositeObjectSinkAdapter.java:497)</div><div><span style="white-space:pre-wrap"> </span>at org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:382)</div>
<div><span style="white-space:pre-wrap"> </span>at org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:235)</div><div><span style="white-space:pre-wrap"> </span>at org.drools.reteoo.EntryPointNode.assertObject(EntryPointNode.java:240)</div>
<div><span style="white-space:pre-wrap"> </span>at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:337)</div><div><span style="white-space:pre-wrap"> </span>at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:298)</div>
<div><span style="white-space:pre-wrap"> </span>at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:888)</div><div><span style="white-space:pre-wrap"> </span>at org.drools.base.DefaultKnowledgeHelper.insert(DefaultKnowledgeHelper.java:187)</div>
<div><span style="white-space:pre-wrap"> </span>at org.drools.base.DefaultKnowledgeHelper.insert(DefaultKnowledgeHelper.java:181)</div><div><span style="white-space:pre-wrap"> </span>at org.zoikks.drools.Rule_create_vcmax_692832fd6e0547e09b6f632175df45ff.defaultConsequence(Rule_create_vcmax_692832fd6e0547e09b6f632175df45ff.java:7)</div>
<div><span style="white-space:pre-wrap"> </span>at org.zoikks.drools.Rule_create_vcmax_692832fd6e0547e09b6f632175df45ffDefaultConsequenceInvokerGenerated.evaluate(Unknown Source)</div><div><span style="white-space:pre-wrap"> </span>at org.zoikks.drools.Rule_create_vcmax_692832fd6e0547e09b6f632175df45ffDefaultConsequenceInvoker.evaluate(Unknown Source)</div>
<div><span style="white-space:pre-wrap"> </span>at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1273)</div><div><span style="white-space:pre-wrap"> </span>... 26 more</div><div><br></div></div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">
This appears to be a race-condition occurring someplace within the app because it executes find some times, yet other times a NPE is thrown. The location where the exception is originating is new to Drools 5.4.0.Final so there is nothing to compare against in previous versions. Has anyone else seen this and/or does anyone know how to solve this problem?</div>
<div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif"><br></div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">
I have attached code that is using Drools 5.4.0.Final. To successfully re-produce the problem, place a breakpoint at org.drools.rule.constraint.MvelConstraint.evaluate() [Line 167] and then step through. The exception has been occurring continuously.</div>
<div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif"><br></div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">
Thanks,</div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif"><br></div><div style="color:rgb(34,34,34);font-size:13px;font-family:arial,sans-serif">
- Darin</div>