<div>The location of the NPE suggests that some field (mmlCommandUid) is null<br>when you insert the object, but some rule wants to access its intValue.<br><br>All fields accessed in all rules must be initialized properly; Drools does not<br>
guard field accesses with "!= null" for you.<br><br>-W<br><br> </div><div class="gmail_quote">On 26 April 2011 20:27, dabar <span dir="ltr"><<a href="mailto:david.barrett.0%2Bdrools@gmail.com">david.barrett.0+drools@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">I've been battling with drools and just wanting a second viewpoint. I'm<br>
using drools 5.2.0 flow and rules.<br>
<br>
I have a rule that inserts a new fact as part of the RHS of the rule and<br>
then I'm getting a null pointer exception - stack below. I assume when the<br>
fact is inserted all the rules are evaluated to build up the agenda.<br>
<br>
I've debugged through drools code and found that in ClassFieldReader object1<br>
is null and object2 is my new fact.<br>
<br>
I'm interested in what a JoinNode represents as I think this is what is<br>
being evaluated. I would guess its a join node in the flow but these don't<br>
contain any rules so perhaps not.<br>
<br>
Similar threads here suggest this is a fault in one of the rules but I have<br>
about 100 rules so working out the culprit isn't straightforward.<br>
What I really want to know is if there a way I can find out which rule is<br>
being assessed for the agenda so I check that rule.<br>
<br>
<br>
Caused by: java.lang.NullPointerException<br>
at<br>
org.drools.base.com.somecompany.prov.rulesbased.facts.ProvResponse1649170666$getMmlCommandUid.getIntValue(Unknown<br>
Source)<br>
at<br>
org.drools.base.ClassFieldReader.getIntValue(ClassFieldReader.java:165)<br>
at<br>
org.drools.base.evaluators.EqualityEvaluatorsDefinition$IntegerEqualEvaluator.evaluate(EqualityEvaluatorsDefinition.java:1522)<br>
at<br>
org.drools.core.util.AbstractHashTable$SingleIndex.equal(AbstractHashTable.java:619)<br>
at<br>
org.drools.core.util.LeftTupleList.matches(LeftTupleList.java:190)<br>
at<br>
org.drools.core.util.LeftTupleIndexHashTable.getOrCreate(LeftTupleIndexHashTable.java:347)<br>
at<br>
org.drools.core.util.LeftTupleIndexHashTable.add(LeftTupleIndexHashTable.java:233)<br>
at org.drools.reteoo.JoinNode.assertLeftTuple(JoinNode.java:65)<br>
at<br>
org.drools.reteoo.SingleLeftTupleSinkAdapter.doPropagateAssertLeftTuple(SingleLeftTupleSinkAdapter.java:189)<br>
at<br>
org.drools.reteoo.SingleLeftTupleSinkAdapter.createAndPropagateAssertLeftTuple(SingleLeftTupleSinkAdapter.java:138)<br>
at<br>
org.drools.reteoo.LeftInputAdapterNode.assertObject(LeftInputAdapterNode.java:148)<br>
at<br>
org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateAssertObject(CompositeObjectSinkAdapter.java:450)<br>
at<br>
org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:378)<br>
at<br>
org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:190)<br>
at<br>
org.drools.reteoo.EntryPointNode.assertObject(EntryPointNode.java:145)<br>
at<br>
org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:1183)<br>
at<br>
org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:1085)<br>
at<br>
org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:889)<br>
at<br>
org.drools.impl.StatefulKnowledgeSessionImpl.insert(StatefulKnowledgeSessionImpl.java:238)<br>
at<br>
com.somecompany.rules.global.RulesUtils.insertFact(RulesUtils.java:159)<br>
at<br>
com.somecompany.rules.common.Rule_Common_HandleUnexpectedResponse___Mark_an_unexpected_response_as_handled_0.defaultConsequence(Rule_Common_HandleUnexpectedResponse___Mark_an_unexpected_response_as_handled_0.java:28)<br>
<font color="#888888"><br>
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