[jboss-jira] [JBoss JIRA] (DROOLS-163) NPE when updating a fact of a FromNode
Mario Fusco (JIRA)
jira-events at lists.jboss.org
Mon Jun 17 04:01:21 EDT 2013
[ https://issues.jboss.org/browse/DROOLS-163?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Mario Fusco resolved DROOLS-163.
--------------------------------
Resolution: Rejected
> NPE when updating a fact of a FromNode
> --------------------------------------
>
> Key: DROOLS-163
> URL: https://issues.jboss.org/browse/DROOLS-163
> Project: Drools
> Issue Type: Bug
> Security Level: Public(Everyone can see)
> Affects Versions: 5.5.0.Final, 6.0.0.Beta2
> Environment: Windows7, JDK 1.6.26
> Reporter: Andreas Volz
> Assignee: Mario Fusco
> Labels: EntryPoint, FactHandle, NPE, update
> Attachments: npe.zip
>
>
> A NullPointerException is thrown when updating a fact of a FromNode.
> Here is the corresponding stack trace:
> {code}
> Exception executing consequence for rule "update_TestObjects_from_TestObjectContainer" in de.avo: java.lang.NullPointerException
> at org.drools.core.runtime.rule.impl.DefaultConsequenceExceptionHandler.handleException(DefaultConsequenceExceptionHandler.java:39)
> at org.drools.core.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1424)
> at org.drools.core.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:1343)
> at org.drools.core.common.DefaultAgenda.fireAllRules(DefaultAgenda.java:1561)
> at org.drools.core.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:637)
> at org.drools.core.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:601)
> at de.avo.Builder.fireAllRules(Builder.java:47)
> at de.avo.NPETest.testWrongFiringOrder(NPETest.java:37)
> 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:597)
> at org.junit.internal.runners.TestMethod.invoke(TestMethod.java:59)
> at org.junit.internal.runners.MethodRoadie.runTestMethod(MethodRoadie.java:98)
> at org.junit.internal.runners.MethodRoadie$2.run(MethodRoadie.java:79)
> at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:87)
> at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:77)
> at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:42)
> at org.junit.internal.runners.JUnit4ClassRunner.invokeTestMethod(JUnit4ClassRunner.java:88)
> at org.junit.internal.runners.JUnit4ClassRunner.runMethods(JUnit4ClassRunner.java:51)
> at org.junit.internal.runners.JUnit4ClassRunner$1.run(JUnit4ClassRunner.java:44)
> at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:27)
> at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:37)
> at org.junit.internal.runners.JUnit4ClassRunner.run(JUnit4ClassRunner.java:42)
> at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
> at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
> at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
> at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
> at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
> at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
> Caused by: java.lang.NullPointerException
> at org.drools.core.base.DefaultKnowledgeHelper.update(DefaultKnowledgeHelper.java:374)
> at org.drools.core.base.DefaultKnowledgeHelper.update(DefaultKnowledgeHelper.java:439)
> at org.drools.core.base.ModifyInterceptor.doAfter(ModifyInterceptor.java:79)
> at org.mvel2.ast.InterceptorWrapper.getReducedValueAccelerated(InterceptorWrapper.java:40)
> at org.mvel2.MVELRuntime.execute(MVELRuntime.java:85)
> at org.mvel2.compiler.CompiledExpression.getDirectValue(CompiledExpression.java:123)
> at org.mvel2.compiler.CompiledExpression.getValue(CompiledExpression.java:119)
> at org.mvel2.compiler.CompiledExpression.getValue(CompiledExpression.java:113)
> at org.mvel2.MVEL.executeExpression(MVEL.java:930)
> at org.drools.core.base.mvel.MVELConsequence.evaluate(MVELConsequence.java:100)
> at org.drools.core.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1414)
> ... 28 more
> {code}
> By debugging the Drools code (version 6.0.0.Beta2) I've found out that in the class FromNode FactHandles are created; e.g. in the method createRightTuple:
> {code:title=FromNode#createRightTuple}
> ...
> if( _handle != null ) {
> // create a handle with the given id
> handle = workingMemory.getFactHandleFactory().newFactHandle( _handle.getId(),
> object,
> _handle.getRecency(),
> null, // set this to null, otherwise it uses the driver fact's entrypoint
> workingMemory,
> null );
> } else {
> handle = workingMemory.getFactHandleFactory().newFactHandle( object,
> null, // set this to null, otherwise it uses the driver fact's entrypoint
> workingMemory,
> null );
> }
> ...
> {code}
> As one can see in the code snippet above, the EntryPoint of the FactHandle is set to null. The newly created FactHandles are stored in the field {{identityMap}} of a knowledge helper (its type is DefaultKnowledgeHelper).
> When the fact that corresponds to the newly created FactHandle has to be updated, the method {{update(FactHandle handle, long mask, Class<?> modifiedClass)}} is called. In this method the EntryPoint of the FactHandle is used to issue the update. Since this EntryPoint has been set to null by the class FromNode, a NPE is thrown. Here is the code snippet where the NPE is thrown:
> {code:title=DefaultKnowledgeHelper}
> public void update(final FactHandle handle, long mask, Class<?> modifiedClass) {
> InternalFactHandle h = (InternalFactHandle) handle;
> ((InternalWorkingMemoryEntryPoint) h.getEntryPoint()).update( h,
> ((InternalFactHandle)handle).getObject(),
> mask,
> modifiedClass,
> this.activation );
> ...
> {code}
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
More information about the jboss-jira
mailing list