I can give this a shot,
but the reason why you suggest this is not obvious to me.
Have you encountered this problem
yourself?
-Jason
From: rules-users-bounces@lists.jboss.org
[rules-users-bounces@lists.jboss.org] On Behalf Of Anstis, Michael (M.)
[manstis1@ford.com]
Sent: Monday, March 10, 2008 5:06
AM
To: Rules Users List
Subject: RE: [rules-users]
Interesting null pointer exception when inserting afact.
I'm no expert but recall there can be problems running
"long running" (subjective) code from AWT's worker
thread.
I thought it was good practice to run your "application
code" in a worker thread. This was the first google hit I had on the
matter.
Cheers,
Mike
Jason,
Can you please
isolate and show us the rule that is creating the problem? It is happening
either in a eval() statement or in a nested property
access.
[]s
Edson
2008/3/7, Jason Partyka <Jason.Partyka@hightowerinc.com>:
Hi,
This
is in relation to drools 4.0.4
I have an interesting problem. I am
getting a null pointer exception when I am inserting a fact into a
StatefulSession object. What is odd about this NPE is that, as far as I
can tell (and I have inserted a breakpoint right before I insert the fact)
that all the properties in the object are initialized, and there are no
rules accessing any thing that could be null.
So here's my
exception trace (just first few lines to get context):
Exception in
thread "AWT-EventQueue-0" org.drools.RuntimeDroolsException:
java.lang.NullPointerException
at
org.drools.rule.EvalCondition.isAllowed(EvalCondition.java:76)
at
org.drools.reteoo.EvalConditionNode.assertTuple(EvalConditionNode.java:145)
at
org.drools.reteoo.SingleTupleSinkAdapter.createAndPropagateAssertTuple(SingleTupleSinkAdapter.java:55)
at
org.drools.reteoo.LeftInputAdapterNode.assertObject(LeftInputAdapterNode.java:116)
at
org.drools.reteoo.SingleObjectSinkAdapter.propagateAssertObject(SingleObjectSinkAdapter.java:22)
at
org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:153)
at
org.drools.reteoo.Rete.assertObject(Rete.java:177)
at
org.drools.reteoo.ReteooRuleBase.assertObject(ReteooRuleBase.java:192)
at
org.drools.reteoo.ReteooWorkingMemory.doInsert(ReteooWorkingMemory.java:71)
at
org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:886)
at
org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:858)
at
org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:659)
at
com.hightower.drools.executablerules.Rules.setTemplate(Rules.java:112)
....
Caused
by: java.lang.NullPointerException
at
org.drools.base.mvel.MVELEvalExpression.evaluate(MVELEvalExpression.java:39)
at
org.drools.rule.EvalCondition.isAllowed(EvalCondition.java:72)
...
39 more
(that setTemplate method is not a drools
template)
Any
ideas?
Thanks,
Jason
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Edson Tirelli
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Core Development
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