[rules-users] Regression with Drools 5.3.0-CR1

[Swindells, Thomas]

I've just tried upgrading from Drools 5.3.0-CR1 from the beta and I've hit a regression.

JBoss seems to have been down for most of today so I haven't been able to raise a Jira for it.

In our model we have Facts which contain fields of java.lang.class, we then have a rule which checks that they aren't null.
Eg
Fact { Class<Object> classField}

Rule "xyz"
When
                Fact(classField != null)
Then
...
End

This is giving the following exception

Caused by: java.lang.ClassCastException: org.drools.base.field.ObjectFieldImpl cannot be cast to org.drools.base.field.ClassFieldImpl
                at org.drools.base.evaluators.EqualityEvaluatorsDefinition$ClassEqualEvaluator.evaluate(EqualityEvaluatorsDefinition.java:1772)
                at org.drools.rule.LiteralRestriction.isAllowed(LiteralRestriction.java:87)
                at org.drools.rule.LiteralConstraint.isAllowed(LiteralConstraint.java:109)
                at org.drools.reteoo.AlphaNode.assertObject(AlphaNode.java:130)
                at org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateAssertObject(CompositeObjectSinkAdapter.java:451)
                at org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:369)
                at org.drools.reteoo.AlphaNode.assertObject(AlphaNode.java:134)
                at org.drools.reteoo.CompositeObjectSinkAdapter.doPropagateAssertObject(CompositeObjectSinkAdapter.java:451)
                at org.drools.reteoo.CompositeObjectSinkAdapter.propagateAssertObject(CompositeObjectSinkAdapter.java:379)
                at org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:204)
                at org.drools.reteoo.EntryPointNode.assertObject(EntryPointNode.java:244)
                at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:330)
                at org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:291)
                at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:882)
                at org.drools.base.DefaultKnowledgeHelper.insert(DefaultKnowledgeHelper.java:180)
                ... 149 more

Wrapping the classField != null within an eval appears to be a work around.

This is in the suspect method:
        public boolean evaluate(InternalWorkingMemory workingMemory,
                                final InternalReadAccessor extractor,
                                final Object object1, final FieldValue object2) {
            Object value1 = extractor.getValue( workingMemory, object1 );
            Object value2 = object2.getValue();
            if ( value2 == null ) {
                ClassFieldImpl classField = (ClassFieldImpl) object2;
                value2 = classField.resolve( workingMemory );
            }
            return comparator.equals( value1, value2 );
        }

I think the if statement just needs an instanceof check as well or some other way to track the fact that null may be a valid value to be comparing with!


Thomas

________________________________

**************************************************************************************
This message is confidential and intended only for the addressee. If you have received this message in error, please immediately notify the postmaster at nds.com and delete it from your system as well as any copies. The content of e-mails as well as traffic data may be monitored by NDS for employment and security purposes. To protect the environment please do not print this e-mail unless necessary.

NDS Limited. Registered Office: One London Road, Staines, Middlesex, TW18 4EX, United Kingdom. A company registered in England and Wales. Registered no. 3080780. VAT no. GB 603 8808 40-00
**************************************************************************************
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/rules-users/attachments/20110926/360bfee6/attachment.html