[rules-users] Property Navigation
Michael B.
michael.bain at mckesson.com
Wed May 7 15:50:39 EDT 2008
Verified this, in my example if I change the line to Bar.setFoo(null) I get
the following error in my test case:
Exception executing predicate
org.drools.base.mvel.MVELPredicateExpression at 6bade9
org.drools.RuntimeDroolsException: Exception executing predicate
org.drools.base.mvel.MVELPredicateExpression at 6bade9
at
org.drools.rule.PredicateConstraint.isAllowed(PredicateConstraint.java:216)
at org.drools.reteoo.AlphaNode.assertObject(AlphaNode.java:132)
at
org.drools.reteoo.SingleObjectSinkAdapter.propagateAssertObject(SingleObjectSinkAdapter.java:22)
at org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:153)
at org.drools.reteoo.Rete.assertObject(Rete.java:175)
at org.drools.reteoo.ReteooRuleBase.assertObject(ReteooRuleBase.java:192)
at
org.drools.reteoo.ReteooWorkingMemory.doInsert(ReteooWorkingMemory.java:71)
at
org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:909)
at
org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:881)
at
org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:682)
at mmg.cm.drools.FooBarTest.testProperties(FooBarTest.java:51)
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:585)
at junit.framework.TestCase.runTest(TestCase.java:154)
at junit.framework.TestCase.runBare(TestCase.java:127)
at junit.framework.TestResult$1.protect(TestResult.java:106)
at junit.framework.TestResult.runProtected(TestResult.java:124)
at junit.framework.TestResult.run(TestResult.java:109)
at junit.framework.TestCase.run(TestCase.java:118)
at junit.framework.TestSuite.runTest(TestSuite.java:208)
at junit.framework.TestSuite.run(TestSuite.java:203)
at
org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestReference.run(JUnit3TestReference.java:128)
at
org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:460)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:673)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:386)
at
org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)
Caused by: org.mvel.CompileException: unable to resolve property: name
at
org.mvel.optimizers.impl.refl.ReflectiveAccessorOptimizer.compileGetChain(ReflectiveAccessorOptimizer.java:288)
at
org.mvel.optimizers.impl.refl.ReflectiveAccessorOptimizer.optimizeAccessor(ReflectiveAccessorOptimizer.java:109)
at
org.mvel.ast.VariableDeepPropertyNode.getReducedValueAccelerated(VariableDeepPropertyNode.java:29)
at
org.mvel.ast.PropertyASTNode.initializePropertyNode(PropertyASTNode.java:77)
at
org.mvel.ast.PropertyASTNode.getReducedValueAccelerated(PropertyASTNode.java:26)
at
org.mvel.ast.BinaryOperation.getReducedValueAccelerated(BinaryOperation.java:21)
at org.mvel.MVELRuntime.execute(MVELRuntime.java:88)
at org.mvel.CompiledExpression.getValue(CompiledExpression.java:111)
at org.mvel.MVEL.executeExpression(MVEL.java:235)
at
org.drools.base.mvel.MVELPredicateExpression.evaluate(MVELPredicateExpression.java:36)
at
org.drools.rule.PredicateConstraint.isAllowed(PredicateConstraint.java:210)
... 28 more
Caused by: org.mvel.PropertyAccessException: unable to resolve property:
name
at
org.mvel.optimizers.impl.refl.ReflectiveAccessorOptimizer.getBeanProperty(ReflectiveAccessorOptimizer.java:382)
at
org.mvel.optimizers.impl.refl.ReflectiveAccessorOptimizer.compileGetChain(ReflectiveAccessorOptimizer.java:257)
... 38 more
Edson Tirelli-3 wrote:
>
> Really? That is a surprise to me... we need to handle that...
>
> Maybe you can open a JIRA for us?
>
> Thanks,
> Edson
>
> 2008/5/6 Alessandro Lazarotti <alessandro at siq.com.br>:
>
>> Thanks Michael, I simulate.. your rule fire with successful.
>>
>> I discovered the problem. The object in property (like Foo in your
>> example), when null, it's not throws NullPointerException, but
>> "org.mvel.PropertyAccessException: unable to resolve property".
>> With that, I never imagined that the problem was nullPointer, but I
>> thought about any access visibility (duh!).
>>
>> []'s
>> Alessandro
>>
>>
>>
>> Michael B. escreveu:
>>
>> Okay, I wrote a test case around the following and it works fine so let
>> > me
>> > know if this isnt what you are working with...
>> >
>> > Foo Class
>> >
>> > public class Foo {
>> > private String m_name;
>> > public String getName()
>> > {
>> > return m_name; }
>> > public void setName(String nm)
>> > {
>> > m_name = nm;
>> > }
>> >
>> > }
>> >
>> >
>> > Bar Class
>> >
>> > public class Bar {
>> > private Foo m_foo;
>> > public Foo getFoo()
>> > {
>> > return m_foo;
>> > }
>> > public void setFoo(Foo f)
>> > {
>> > m_foo = f;
>> > }
>> > public String toString()
>> > {
>> > return "I have a foo with a name of " + m_foo.getName();
>> > }
>> >
>> > }
>> >
>> > DRL Rule
>> >
>> > rule "FooBar Rule"
>> >
>> > when
>> > $bar : Bar( foo.name != "Wrong" )
>> > then System.out.println("Test Successful - " +
>> > $bar.toString());
>> >
>> > end
>> >
>> >
>> > Junit Test Case
>> >
>> > public void testProperties() {
>> > try
>> > {
>> > final Reader source = new InputStreamReader(
>> > FooBarTest.class.getResourceAsStream( "FooBar.drl" ) );
>> > RuleBase ruleBase = RuleBaseFactory.newRuleBase();
>> > PackageBuilder builder = new PackageBuilder();
>> > builder.addPackageFromDrl(source);
>> > if ( builder.hasErrors() ) {
>> > System.out.println( builder.getErrors().toString() );
>> > throw new RuntimeException( "Unable to compile
>> > \"FooBar.drl\".");
>> > }
>> > //get the compiled package (which is
>> > serializable)
>> > final Package pkg = builder.getPackage();
>> >
>> > //add the package to a rulebase (deploy the rule package).
>> > ruleBase.addPackage( pkg );
>> > final StatefulSession session =
>> > ruleBase.newStatefulSession();
>> > Foo foo = new Foo();
>> > foo.setName("Test");
>> > Bar bar = new Bar();
>> > bar.setFoo(foo);
>> > session.insert(bar);
>> > session.fireAllRules();
>> > }
>> > catch (Exception e)
>> > {
>> > System.out.println(e.getMessage());
>> > e.printStackTrace();
>> > fail(e.getMessage());
>> > }
>> >
>> > }
>> >
>> >
>> >
>> >
>> >
>> >
>> _______________________________________________
>> rules-users mailing list
>> rules-users at lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/rules-users
>>
>
>
>
> --
> Edson Tirelli
> JBoss Drools Core Development
> Office: +55 11 3529-6000
> Mobile: +55 11 9287-5646
> JBoss, a division of Red Hat @ www.jboss.com
>
> _______________________________________________
> rules-users mailing list
> rules-users at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
>
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