[rules-users] ClassCastException when KnowledgeAgent loads declared type

[Esteban Aliverti]

This is a known bug: https://issues.jboss.org/browse/JBRULES-2962 Some
improvements were made in 5.3 and 5.4 but AFAIK, the issue still remains.
Could you please try using 5.4.SNAPSHOT ot beta1 to see if the error
persists?

Best Regards,

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

Esteban Aliverti
- Developer @ http://www.plugtree.com
- Blog @ http://ilesteban.wordpress.com


On Mon, Jan 16, 2012 at 7:21 PM, lhorton <LHorton at abclegal.com> wrote:

> Code level:  5.2.0.Final
>
> I have a DRL file that includes a declared type:
>
> package com.abclegal.rules.servicerequirements
> declare TransgressionMetaData
>        attempt : ServiceAttempt
>        requirement : Requirement
> end
>
> The package loads the first time and its rules run without error.  If I
> make
> a change to the file and hot-deploy it (copy it to the server), the
> ResourceChangeScanner picks up the file and KnowledgeAgent loads it, but
> when any rule from that package subsequently fires, I get a
> ClassCastException on the declared type:
>
> com.abclegal.rules.servicerequirements.TransgressionMetaData cannot be cast
> to com.abclegal.rules.servicerequirements.TransgressionMetaData
>
> it appears the KnowledgeAgent is not replacing the existing (in working
> memory) definition of the declared type, but instead is creating a new one
> with a different hash code.
>
> looks like a bug?
>
> Full stack trace:
> Caused by: RulesConsequenceException executing consequence for rule
> "PHOTO_WHEN_SERVED: Photo must be taken if served." in
> com.abclegal.rules.servicerequirements
> [Error: drools.insert(new TransgressionMetaData($attempt,$req)):
> com.abclegal.rules.servicerequirements.TransgressionMetaData cannot be cast
> to com.abclegal.rules.servicerequirements.TransgressionMetaData]
> [Near : {... @Modify with($attempt){ ....}]
>             ^
> [Line: 1, Column: 1]
> java.lang.ClassCastException:
> com.abclegal.rules.servicerequirements.TransgressionMetaData cannot be cast
> to com.abclegal.rules.servicerequirements.TransgressionMetaData
> Rules working memory:
> Fact ServiceAttempt id: 17
>        at
>
> com.abclegal.rules.utility.RulesConsequenceExceptionHandler.handleException(RulesConsequenceExceptionHandler.java:24)
>        at
> org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:912)
>        at
> org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:845)
>        at
> org.drools.common.DefaultAgenda.fireAllRules(DefaultAgenda.java:1056)
>        at
>
> org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:733)
>        at
>
> org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:699)
>        at
>
> org.drools.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:218)
>        at
>
> org.drools.impl.StatelessKnowledgeSessionImpl.execute(StatelessKnowledgeSessionImpl.java:305)
>        at
>
> com.abclegal.rules.server.RulesServiceImpl.execute(RulesServiceImpl.java:378)
>        ... 44 more
> Caused by: [Error: drools.insert(new TransgressionMetaData($attempt,$req)):
> com.abclegal.rules.servicerequirements.TransgressionMetaData cannot be cast
> to com.abclegal.rules.servicerequirements.TransgressionMetaData]
> [Near : {... @Modify with($attempt){ ....}]
>             ^
> [Line: 1, Column: 1]
>        at
>
> org.mvel2.optimizers.impl.refl.ReflectiveAccessorOptimizer.compileGetChain(ReflectiveAccessorOptimizer.java:409)
>        at
>
> org.mvel2.optimizers.impl.refl.ReflectiveAccessorOptimizer.optimizeAccessor(ReflectiveAccessorOptimizer.java:140)
>        at
>
> org.mvel2.optimizers.dynamic.DynamicOptimizer.optimizeAccessor(DynamicOptimizer.java:67)
>        at org.mvel2.ast.ASTNode.optimize(ASTNode.java:154)
>        at
> org.mvel2.ast.ASTNode.getReducedValueAccelerated(ASTNode.java:110)
>        at org.mvel2.MVELRuntime.execute(MVELRuntime.java:86)
>        at
> org.mvel2.compiler.CompiledExpression.getValue(CompiledExpression.java:122)
>        at
> org.mvel2.compiler.CompiledExpression.getValue(CompiledExpression.java:115)
>        at org.mvel2.MVEL.executeExpression(MVEL.java:928)
>        at
> org.drools.base.mvel.MVELConsequence.evaluate(MVELConsequence.java:105)
>        at
> org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:906)
>        ... 51 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:1066)
>        at
>
> org.mvel2.optimizers.impl.refl.ReflectiveAccessorOptimizer.compileGetChain(ReflectiveAccessorOptimizer.java:338)
>        ... 61 more
>
>
> --
> View this message in context:
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> Sent from the Drools: User forum mailing list archive at Nabble.com.
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