On Thu, Jan 17, 2013 at 7:29 AM, Wolfgang Laun
<wolfgang.laun@gmail.com> wrote:
The error occurs when the following rule fires ;-)
rule "error occurs"
$fact1: Fact( $class: class )
$fact2: Fact( class == $class, this != $fact1 )
Field( $name: name, type == $class, modifiers == Modifier.PUBLIC )
Rule( dialect == "mvel",
$rule: name
rightHandSide matches (".\\s*" + $name + "\\s*=\\s*\S+\\s*;" ) );
then
System.out.println( "When rule " + $rule + " fires, an exception occurs" );
end
In words:
All the following conditions must be met:
* WM contains at least two facts of the same type
* there is a public field
* the rule's dialect is set to MVEL
* a rule's right hand side contains an assignment to the public field
Occurs with versions 5.[2345].0
-W
On 16/01/2013, Chang Liu <CLiu@deltadentalmi.com> wrote:
> A rule to repro this situation:
>
> The rule:
> ...
> rule "Assignment In Action Test"
> when
> obj : Foo()
> then
> obj.x = 1;
> System.out.println("Rule Fired!");
> end
> ...
>
> Definition of class Foo:
> public class Foo {
> public int x;
> public int getX() {
> return x;
> }
> public void setX(int x) {
> this.x = x;
> }
> }
>
> Objects been inserted:
> Foo foo1 = new Foo();
> foo1.x = 0;
> Foo foo2 = new Foo();
> Foo2.x = 1000;
>
> Note that if only one Foo object is inserted, things work fine. If more than
> one Foo objects are inserted, we see this Exception:
>
> Exception executing consequence for rule "Assignment In Action Test" in
> com.sample: java.lang.RuntimeException: unable to access field
> at
> org.drools.runtime.rule.impl.DefaultConsequenceExceptionHandler.handleException(DefaultConsequenceExceptionHandler.java:39)
> at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1283)
> at org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:1209)
> at org.drools.common.DefaultAgenda.fireAllRules(DefaultAgenda.java:1442)
> 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.sample.AssignmentInActionTestMain.main(AssignmentInActionTestMain.java:37)
> Caused by: java.lang.RuntimeException: unable to access field
> at
> org.mvel2.optimizers.impl.refl.nodes.DynamicFieldAccessor.setValue(DynamicFieldAccessor.java:66)
> at
> org.mvel2.optimizers.impl.refl.nodes.IndexedVariableAccessor.setValue(IndexedVariableAccessor.java:43)
> at
> org.mvel2.compiler.CompiledAccExpression.setValue(CompiledAccExpression.java:59)
> at
> org.mvel2.ast.DeepAssignmentNode.getReducedValueAccelerated(DeepAssignmentNode.java:92)
> at org.mvel2.MVELRuntime.execute(MVELRuntime.java:85)
> at
> org.mvel2.compiler.CompiledExpression.getValue(CompiledExpression.java:126)
> at org.mvel2.MVEL.executeExpression(MVEL.java:930)
> at org.drools.base.mvel.MVELConsequence.evaluate(MVELConsequence.java:101)
> at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1273)
> ... 6 more
> Caused by: java.lang.NullPointerException
> at org.mvel2.DataConversion.convert(DataConversion.java:118)
> at
> org.mvel2.optimizers.impl.refl.nodes.DynamicFieldAccessor.setValue(DynamicFieldAccessor.java:61)
> ... 14 more
>
> -----Original Message-----
> From: rules-users-bounces@lists.jboss.org
> [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Wolfgang Laun
> Sent: Wednesday, January 16, 2013 10:35 AM
> To: Rules Users List
> Subject: Re: [rules-users] Exception executing consequence for rule xxx in
> yyy: java.lang.RuntimeException: unable to access field
>
> What's the type of $billingOutputRuleContext.retroPreviousBillAmount?
>
> On 16/01/2013, magaram <magaram@deltadentalmi.com> wrote:
>> The behavior stated seems very erratic as other similar rules are
>> executing.
>> Also note that the fields in the consequence have a visibility of public.
>> Are there any known issues surrounding this?
>>
>>
>>
>> --
>> View this message in context:
>> http://drools.46999.n3.nabble.com/Exception-executing-consequence-for-
>> rule-xxx-in-yyy-java-lang-RuntimeException-unable-to-access-field-tp40
>> 21553p4021576.html Sent from the Drools: User forum mailing list
>> archive at Nabble.com.
>> _______________________________________________
>> rules-users mailing list
>> rules-users@lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/rules-users
>>
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