[rules-users] peephole technique -> cast to java.lang.Number problem
Wolfgang Laun
wolfgang.laun at gmail.com
Mon Nov 4 07:42:39 EST 2013
Maybe s.o. can contradict, but in 5.5.0 (and even before) it's MVEL
for dealing with constraint expressions anyway, behind the scenes.
-W
On 04/11/2013, Alexander Wolf <mail at alexander-wolf.net> wrote:
> MVEL was my first suspect as well, but the same rules in java dialect (just
> added setters/getters)
> produced same exceptions.
>
> Alex
>
> On 04 Nov 2013, at 07:43, Wolfgang Laun <wolfgang.laun at gmail.com> wrote:
>
>> You never know what an expression suffers when it is thrown into
>> the MVEL machinery, (Mario's continuing efforts notwithstanding).
>> Documentation is sparse...
>>
>> To be on the safe side, I'd probably have written
>>
>> rule "count old"
>> when
>> $le : LastEvent($ev: event )
>> $last: Event( this == $ev )
>> $old : Event( this before [1ms , 5s] $last )
>> then
>> System.out.println($old);
>> end
>>
>> -W
>>
>>
>>
>>
>> On 03/11/2013, Alexander Wolf <mail at alexander-wolf.net> wrote:
>>> Okey I got a little further: This works:
>>>
>>> rule "count old"
>>> when
>>> $le : LastEvent($ts : event.timestamp)
>>> $old : Event(this before [1ms , 5s] $ts)
>>> then
>>> System.out.println($old);
>>> end
>>>
>>> but then why does this not work ?!
>>>
>>> rule "count old"
>>> when
>>> $le : LastEvent($event : event)
>>> $old : Event(this before [1ms , 5s] $event.timestamp)
>>> then
>>> System.out.println($old);
>>> end
>>>
>>> To me this seems to be a bug, that occurs as soon as I set an event as
>>> member of a fact (the LastEvent) -> implementing the peephole technique.
>>> At least I got it to do what I want...but not as "niceley..." as
>>> expected.
>>>
>>> -
>>>
>>>
>>> On 02 Nov 2013, at 18:11, Alexander Wolf <mail at alexander-wolf.net>
>>> wrote:
>>>
>>>> Drools 5.5.0 + Fusion / stateful session / STREAM mode
>>>>
>>>> Hi,
>>>>
>>>> I try to improve my rules using peephole technique (Thanks @W)
>>>> I think I got it right, but now I am stuck with a problem.
>>>>
>>>> I want to keep a reference to my latest inserted event. Problem: the
>>>> rule
>>>> "print old" gives me an Exception (see below).
>>>> I think the peephole itself works pretty well, but somehow my Event
>>>> Object
>>>> (POJO with: Date timestamp, int value) is making problems when I try to
>>>> use "before". (see marked line, when commenting it out, the rules run
>>>> alright)
>>>>
>>>> dialect "mvel"
>>>>
>>>> import java.util.Date
>>>> import com.testmodel.Event
>>>>
>>>>
>>>> //declarations
>>>> declare Event
>>>> @role(event)
>>>> @timestamp( timestamp )
>>>> end
>>>>
>>>> declare LastEvent
>>>> event: Event
>>>> end
>>>>
>>>>
>>>> rule "init"
>>>> when
>>>> //once...
>>>> then
>>>> System.out.println("init");
>>>> LastEvent l = new LastEvent();
>>>> Event e = new Event();
>>>> e.timestamp = new Date();
>>>> e.value = 0;
>>>> l.event = e;
>>>> insert(l);
>>>> end
>>>>
>>>> rule "update LastEvent"
>>>> no-loop
>>>> salience 99
>>>> when
>>>> $event : Event()
>>>> $last : LastEvent()
>>>> then
>>>> System.out.println("update LastEvent");
>>>> retract ($last)
>>>> LastEvent l = new LastEvent();
>>>> l.event = $event;
>>>> insert(l);
>>>> end
>>>>
>>>>
>>>> rule "count old"
>>>> when
>>>> LastEvent($last : event)
>>>> $old : Event(this before [0 , 5s] $last) //<<<<<<<<<< THIS IS
>>>> EVIL?!
>>>> then
>>>> System.out.println($old);
>>>> end
>>>>
>>>> My test code looks like this:
>>>>
>>>> Event event = new Event(new Date(), 1);
>>>> ksession.insert(event);
>>>> ksession.fireAllRules();
>>>>
>>>> //sleep 1+ sec
>>>> Thread.sleep(1001);
>>>>
>>>> Event event2 = new Event(new Date(), 2);
>>>> ksession.insert(event2);
>>>> ksession.fireAllRules();
>>>>
>>>>
>>>> And this is the Exception I get:
>>>>
>>>> Exception executing consequence for rule "init" in testEasierLife:
>>>> [Error:
>>>> drools.insert(l): com.testmodel.Event cannot be cast to
>>>> java.lang.Number]
>>>> [Near : {... System.out.println("init"); ....}]
>>>> ^
>>>> [Line: 1, Column: 1]
>>>> at
>>>> org.drools.runtime.rule.impl.DefaultConsequenceExceptionHandler.handleException(DefaultConsequenceExceptionHandler.java:39)
>>>> at
>>>> org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1297)
>>>> at
>>>> org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:1221)
>>>> at
>>>> org.drools.common.DefaultAgenda.fireAllRules(DefaultAgenda.java:1456)
>>>> at
>>>> org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:710)
>>>> at
>>>> org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:674)
>>>> at
>>>> org.drools.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:230)
>>>> at com.Test.test(PeepholeTest.java:65)
>>>> 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.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
>>>> at
>>>> org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
>>>> at
>>>> org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
>>>> at
>>>> org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
>>>> at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
>>>> at
>>>> org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
>>>> at
>>>> org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
>>>> at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
>>>> at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
>>>> at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
>>>> at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
>>>> at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
>>>> at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
>>>> 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: [Error: drools.insert(l): com.testmodel.Event cannot be cast
>>>> to
>>>> java.lang.Number]
>>>> [Near : {... System.out.println("init"); ....}]
>>>> ^
>>>> [Line: 1, Column: 1]
>>>> at
>>>> org.mvel2.optimizers.impl.refl.ReflectiveAccessorOptimizer.compileGetChain(ReflectiveAccessorOptimizer.java:416)
>>>> at
>>>> org.mvel2.optimizers.impl.refl.ReflectiveAccessorOptimizer.optimizeAccessor(ReflectiveAccessorOptimizer.java:143)
>>>> at org.mvel2.ast.ASTNode.optimize(ASTNode.java:159)
>>>> at org.mvel2.ast.ASTNode.getReducedValueAccelerated(ASTNode.java:115)
>>>> 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.base.mvel.MVELConsequence.evaluate(MVELConsequence.java:104)
>>>> at
>>>> org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1287)
>>>> ... 29 more
>>>> Caused by: java.lang.reflect.InvocationTargetException
>>>> 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.mvel2.optimizers.impl.refl.ReflectiveAccessorOptimizer.getMethod(ReflectiveAccessorOptimizer.java:1104)
>>>> at
>>>> org.mvel2.optimizers.impl.refl.ReflectiveAccessorOptimizer.getMethod(ReflectiveAccessorOptimizer.java:987)
>>>> at
>>>> org.mvel2.optimizers.impl.refl.ReflectiveAccessorOptimizer.compileGetChain(ReflectiveAccessorOptimizer.java:377)
>>>> ... 39 more
>>>> Caused by: java.lang.ClassCastException: com.testmodel.Event cannot be
>>>> cast to java.lang.Number
>>>> at
>>>> org.drools.base.evaluators.BeforeEvaluatorDefinition$BeforeEvaluator.evaluateCachedLeft(BeforeEvaluatorDefinition.java:337)
>>>> at
>>>> org.drools.rule.constraint.EvaluatorConstraint.isAllowedCachedLeft(EvaluatorConstraint.java:67)
>>>> at
>>>> org.drools.common.SingleBetaConstraints.isAllowedCachedLeft(SingleBetaConstraints.java:125)
>>>> at org.drools.reteoo.JoinNode.propagateFromLeft(JoinNode.java:105)
>>>> at org.drools.reteoo.JoinNode.assertLeftTuple(JoinNode.java:95)
>>>> at
>>>> org.drools.reteoo.SingleLeftTupleSinkAdapter.doPropagateAssertLeftTuple(SingleLeftTupleSinkAdapter.java:196)
>>>> at
>>>> org.drools.reteoo.SingleLeftTupleSinkAdapter.createAndPropagateAssertLeftTuple(SingleLeftTupleSinkAdapter.java:145)
>>>> at
>>>> org.drools.reteoo.LeftInputAdapterNode.assertObject(LeftInputAdapterNode.java:154)
>>>> at
>>>> org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateAssertObject(CompositeObjectSinkAdapter.java:497)
>>>> at
>>>> org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:382)
>>>> at
>>>> org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:235)
>>>> at
>>>> org.drools.reteoo.EntryPointNode.assertObject(EntryPointNode.java:240)
>>>> at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:350)
>>>> at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:311)
>>>> at
>>>> org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:903)
>>>> at
>>>> org.drools.base.DefaultKnowledgeHelper.insert(DefaultKnowledgeHelper.java:192)
>>>> at
>>>> org.drools.base.DefaultKnowledgeHelper.insert(DefaultKnowledgeHelper.java:186)
>>>> ... 46 more
>>>>
>>>>
>>>>
>>>>
>>>
>>>
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>
>
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