I am trying to sequentially perform two rules executions using two different classloaders in the same VM. I create completely new state for each execution, yet I still fail on the second execution. I believe this has to do with some internal static cached state that JBossRules is maintaining. A snippet of the code and exeception are shown in this email. public void demo() throws Exception { // Save original classloader ClassLoader original = Thread.currentThread().getContextClassLoader(); // Create Classloader 1 with parent of original FooClassLoader loader1 = new FooClassLoader(original); Thread.currentThread().setContextClassLoader(loader1); testRules(); // Success so far... // Create Classloader 2 with parent of original FooClassLoader loader2 = new FooClassLoader(original); Thread.currentThread().setContextClassLoader(loader2); testRules(); // Never make it to here. // Restore Thread.currentThread().setContextClassLoader(original); } private void testRules() throws Exception { PackageBuilder builder = new PackageBuilder(); Package pkg = buildPackage(new String[] { "Foo.drl" }, builder); RuleBase base = RuleBaseFactory.newRuleBase(); base.addPackage(pkg); StatelessSession session = base.newStatelessSession(); final ClassLoader loader = Thread.currentThread().getContextClassLoader(); Object inst = loader.loadClass("com.foo.Foo").newInstance(); session.execute(new Object[] { inst }); } Exception in thread "main" java.lang.ClassCastException: adixon.prototype.rules.classloader.demo.copy.FooShadowProxy at org.drools.base.adixon.prototype.rules.classloader.demo.copy.Foo$getName.getValue(Unknown Source) at org.drools.base.ClassFieldExtractor.getValue(ClassFieldExtractor.java:94) at org.drools.base.evaluators.StringFactory$StringEqualEvaluator.evaluate(StringFactory.java:85) at org.drools.rule.LiteralRestriction.isAllowed(LiteralRestriction.java:61) at org.drools.rule.LiteralConstraint.isAllowed(LiteralConstraint.java:82) at org.drools.reteoo.AlphaNode.assertObject(AlphaNode.java:121) at org.drools.reteoo.SingleObjectSinkAdapter.propagateAssertObject(SingleObjectSinkAdapter.java:20) at org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:159) at org.drools.reteoo.Rete.assertObject(Rete.java:175) 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:772) at org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:584) at org.drools.reteoo.ReteooStatelessSession.execute(ReteooStatelessSession.java:63) at adixon.prototype.rules.classloader.demo.copy.Driver.testRules(Driver.java:47) at adixon.prototype.rules.classloader.demo.copy.Driver.go(Driver.java:33) at adixon.prototype.rules.classloader.demo.copy.Driver.main(Driver.java:17) _______________________________________________ rules-dev mailing list rules-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-dev