Predicate Null Pointer exception when using Java 5 Enum ------------------------------------------------------- Key: JBRULES-1045 URL: http://jira.jboss.com/jira/browse/JBRULES-1045 Project: JBoss Rules Issue Type: Bug Security Level: Public (Everyone can see) Affects Versions: 4.0.0.GA Environment: Windows XP sp2, Jboss Rules 4.0.0 GA, Sun Java 1.5.0_11 VM, Eclipse 3.3 with JBOss Rules IDE 4.0 Reporter: christopher barham Assigned To: Mark Proctor Java 5 enums as column constraint do not work as expected. Cqauses Null pointer exception in mvel.MVELPredicateExpression.evaluate. Using modified Eclipse generated Sample project to demonstrate: DroolsTest now has an Enum for it's Message: package com.sample; import java.io.InputStreamReader; import java.io.Reader; import org.drools.RuleBase; import org.drools.RuleBaseFactory; import org.drools.WorkingMemory; import org.drools.compiler.PackageBuilder; import org.drools.rule.Package; /** * This is a sample file to launch a rule package from a rule source file. */ public class DroolsTest { public static final void main(String[] args) { try { RuleBase ruleBase = readRule(); WorkingMemory workingMemory = ruleBase.newStatefulSession(); workingMemory.insert(Message.HELLO); workingMemory.fireAllRules(); } catch (Throwable t) { t.printStackTrace(); } } private static RuleBase readRule() throws Exception { // read in the source Reader source = new InputStreamReader(DroolsTest.class.getResourceAsStream("/Sample.drl")); PackageBuilder builder = new PackageBuilder(); builder.addPackageFromDrl(source); Package pkg = builder.getPackage(); RuleBase ruleBase = RuleBaseFactory.newRuleBase(); ruleBase.addPackage(pkg); return ruleBase; } public enum Message { GOODBYE, HELLO; } } The Sample.drl rule is modified to: package com.sample import com.sample.DroolsTest.Message; rule "Hello World" when m : Message( Message.HELLO ) then System.out.println( m ); end Stack trace given is: org.drools.RuntimeDroolsException: Exception executing predicate org.drools.base.mvel.MVELPredicateExpression@10382a9 at org.drools.rule.PredicateConstraint.isAllowed(PredicateConstraint.java:197) at org.drools.reteoo.AlphaNode.assertObject(AlphaNode.java:122) at org.drools.reteoo.SingleObjectSinkAdapter.propagateAssertObject(SingleObjectSinkAdapter.java:20) at org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:168) at org.drools.reteoo.Rete.assertObject(Rete.java:168) at org.drools.reteoo.ReteooRuleBase.assertObject(ReteooRuleBase.java:190) at org.drools.reteoo.ReteooWorkingMemory.doInsert(ReteooWorkingMemory.java:70) at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:848) at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:822) at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:623) at com.sample.DroolsTest.main(DroolsTest.java:21) Caused by: java.lang.NullPointerException at org.drools.base.mvel.MVELPredicateExpression.evaluate(MVELPredicateExpression.java:39) at org.drools.rule.PredicateConstraint.isAllowed(PredicateConstraint.java:191) ... 10 more -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://jira.jboss.com/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira