[rules-users] rule on Array of custom Object

[stefano corna]

hello,
im using drools 5.0 on eclipse and i have a problem. i want to use an array
of object in my rule condition.
now i try to explain:
i have my java class with the array attribute
-------------------------------------------------
public static class Message {

   public numbers[] numbersArray;

}
--------------------------------------------
and the numbers class that rapresent the objects contained in numbersArray
----------------------------------------------
public static class numbers
{
   public int first;
   public int last;
}
--------------------------------------------------
my goal is make a rule that check if Message.numbersArray[0].first="value"
i use
-------------------------------------------------
rule "rule_001"

dialect "mvel"
when
        $msg : Message(numbersArray[0].first=="1")

then
                System.out.println("something....");
end
-------------------------------
and on runtime it give me this error:
---------------------------------------
org.drools.RuntimeDroolsException: Exception executing predicate
numbersArray[0].first=="1"
        at
org.drools.rule.PredicateConstraint.isAllowed(PredicateConstraint.java:279)
        at org.drools.reteoo.AlphaNode.assertObject(AlphaNode.java:143)
        at
org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateAssertObject(CompositeObjectSinkAdapter.java:360)

        at
org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:344)

        at
org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:185)
        at
org.drools.reteoo.EntryPointNode.assertObject(EntryPointNode.java:146)
        at
org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:1046)

        at
org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:1001)

        at
org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:788)

        at
org.drools.impl.StatefulKnowledgeSessionImpl.insert(StatefulKnowledgeSessionImpl.java:216)

        at com.sample.DroolsTest.main(DroolsTest.java:47)
Caused by: [Error: unable to access property (null parent): first]
[Near : {... Unknown ....}]
             ^
[Line: 1, Column: 0]
        at
org.mvel2.optimizers.impl.refl.ReflectiveAccessorOptimizer.getMethod(ReflectiveAccessorOptimizer.java:861)

        at
org.mvel2.optimizers.impl.refl.ReflectiveAccessorOptimizer.getBeanProperty(ReflectiveAccessorOptimizer.java:585)

        at
org.mvel2.optimizers.impl.refl.ReflectiveAccessorOptimizer.compileGetChain(ReflectiveAccessorOptimizer.java:313)

        at
org.mvel2.optimizers.impl.refl.ReflectiveAccessorOptimizer.optimizeAccessor(ReflectiveAccessorOptimizer.java:138)

        at
org.mvel2.ast.ASTNode.getReducedValueAccelerated(ASTNode.java:133)
        at
org.mvel2.ast.BinaryOperation.getReducedValueAccelerated(BinaryOperation.java:102)

        at org.mvel2.MVELRuntime.execute(MVELRuntime.java:85)
        at
org.mvel2.compiler.CompiledExpression.getValue(CompiledExpression.java:107)
        at org.mvel2.MVEL.executeExpression(MVEL.java:978)
        at
org.drools.base.mvel.MVELPredicateExpression.evaluate(MVELPredicateExpression.java:75)

        at
org.drools.rule.PredicateConstraint.isAllowed(PredicateConstraint.java:272)
        ... 10 more
-------------------------------------------------------
moreover if i try to print the "first" value:
.
.
.
then
                System.out.println(numbersArray[0].first);
end
appear this new error and i cant compile:
"BuildError: Unable to build expression for 'consequence': Failed to
compile: 1 compilation error(s):
 - (1,12) unqualified type in strict mode for: numbersArray'
System.out.println(numbersArray[0].first);
'"

someone can kindly help me?
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/rules-users/attachments/20091214/74d64ddb/attachment.html