I cannot confirm/reproduce this with 5.1.1. Please provide version info and a complete example causing this error? -W On 6 February 2011 02:18, OlliSee <o.roess(a)seeburger.de&gt; wrote: > > Hi folks, another bug discovered here? > > This rule yields a really nice exception > > rule "Test" > when > $list : List() from collect ( A() over window:time(5s) ) > Number($avg : doubleValue) from accumulate( A($num : num) > from $list, average($num)) > then > ... > end > > whereas > Number($avg : doubleValue) from accumulate( A($num : num) over > window:time(5s), average($num)) > works fine. > > So it seems I can't accumulate over the list. But would be quite handy if > I > had more than one accumulation to do and didn't want to rewrite all the > constraints in each accumulation statement. I could just use the list, but > that results in the exception below. > > > Exception in thread "Thread-5" org.drools.RuntimeDroolsException: > Unexpected > exception executing action > org.drools.rule.SlidingTimeWindow$BehaviorExpireWMAction@46fef3 > at > > org.drools.common.AbstractWorkingMemory.executeQueuedActions(AbstractWorkingMemory.java:1473) > at > > org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:1159) > at > > org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:1123) > at > > org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:917) > at > > org.drools.impl.StatefulKnowledgeSessionImpl.insert(StatefulKnowledgeSessionImpl.java:251) > at > trafficsys.SessionInterface.insertAndFire(SessionInterface.java:144) > at > > trafficsys.cep.SensorEventGenerator.generateEvents(SensorEventGenerator.java:80) > at de.trafficsimulation.MicroStreet.update(MicroStreet.java:393) > at de.trafficsimulation.SimCanvas.run(SimCanvas.java:401) > at java.lang.Thread.run(Unknown Source) > Caused by: java.lang.NullPointerException > at > org.drools.reteoo.AccumulateNode.getFirstMatch(AccumulateNode.java:967) > at > org.drools.reteoo.AccumulateNode.splitList(AccumulateNode.java:920) > at > > org.drools.reteoo.AccumulateNode.removePreviousMatchesForLeftTuple(AccumulateNode.java:874) > at > org.drools.reteoo.AccumulateNode.retractLeftTuple(AccumulateNode.java:205) > at > > org.drools.reteoo.CompositeLeftTupleSinkAdapter.doPropagateRetractLeftTuple(CompositeLeftTupleSinkAdapter.java:238) > at > > org.drools.reteoo.CompositeLeftTupleSinkAdapter.propagateRetractLeftTupleDestroyRightTuple(CompositeLeftTupleSinkAdapter.java:138) > at > org.drools.reteoo.AccumulateNode.retractLeftTuple(AccumulateNode.java:212) > at > > org.drools.reteoo.SingleLeftTupleSinkAdapter.doPropagateRetractLeftTuple(SingleLeftTupleSinkAdapter.java:217) > at > > org.drools.reteoo.SingleLeftTupleSinkAdapter.propagateRetractLeftTuple(SingleLeftTupleSinkAdapter.java:91) > at > > org.drools.reteoo.AccumulateNode.evaluateResultConstraints(AccumulateNode.java:648) > at > > org.drools.reteoo.AccumulateNode.removePreviousMatchesForRightTuple(AccumulateNode.java:903) > at > > org.drools.reteoo.AccumulateNode.retractRightTuple(AccumulateNode.java:303) > at > org.drools.rule.SlidingTimeWindow.expireTuples(SlidingTimeWindow.java:167) > at > > org.drools.rule.SlidingTimeWindow$BehaviorExpireWMAction.execute(SlidingTimeWindow.java:329) > at > > org.drools.common.AbstractWorkingMemory.executeQueuedActions(AbstractWorkingMemory.java:1471) > ... 9 more > > > -- > View this message in context: > http://drools-java-rules-engine.46999.n3.nabble.com/Accumulating-over-a-l... > Sent from the Drools - User mailing list archive at Nabble.com. > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users >