I'm pretty sure that this is a bug. When compiling a DRL from a Chenge Set, the resulting package in the Knowledge Base does not contain declare'd types that do not contain fields; it only contains declares with at least one field. This results in a ClassObjectTypeConf with a typeDecl == null, and the damage is done. I'd say that this is a show stopper for any combination of ChangeSet / Pojo as Event. -W On 12 July 2011 19:32, John <jfullard(a)progeny.net&gt; wrote: > Hello, > > I've been messing with this for days now and can't get to the bottom of > this. I'm using drools 5.2.0 Final and setting up my KnowledgeBase with a > KnowledgeAgent which is pulling a package from guvnor (also 5.2.0 Final). > I > do NOT get this error if I use a KnowledgeBuilder and add the exact same > drl > file as a resource. > > If the DRL in guvnor has a rule that uses a sliding window, i get an NPE > when trying to insert an object and the following stack trace: > > java.lang.NullPointerException > at > > org.drools.reteoo.ReteooFactHandleFactory.newFactHandle(ReteooFactHandleFactory.java:56) > at > > org.drools.common.AbstractFactHandleFactory.newFactHandle(AbstractFactHandleFactory.java:80) > at > > org.drools.common.AbstractFactHandleFactory.newFactHandle(AbstractFactHandleFactory.java:65) > at > org.drools.common.NamedEntryPoint.createHandle(NamedEntryPoint.java:705) > at > org.drools.common.NamedEntryPoint.insert(NamedEntryPoint.java:282) > at > > org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:905) > at > > org.drools.common.AbstractWorkingMemory.insert(AbstractWorkingMemory.java:864) > at > > org.drools.impl.StatefulKnowledgeSessionImpl.insert(StatefulKnowledgeSessionImpl.java:255) > at john.DroolsError.runRules(DroolsError.java:48) > at john.DroolsError.main(DroolsError.java:40) > > Here is the DRL: > > 1. | package drools > 2. | import simple.SimpleType > 3. | > 4. | > 5. | > 6. | > 7. | > 8. | > 9. | import simple.SimpleType; > 10. | > 11. | declare SimpleType > 12. | @role(event) > 13. | end > 14. | > 15. | rule "timer" > 16. | timer (cron:5/5 * * * * ?) > 17. | when > 18. | $newest : Number() > 19. | from accumulate( SimpleType ($num : number) over > window:time(5s), > 20. | max($num) ) > 21. | $st : SimpleType( number == $newest.intValue ) > 22. | then > 23. | System.out.println("SimpleType: " + $st.number); > 24. | end > (note: the first import of simple.SimpleType comes from the package > configuration in guvnor, the second is in the drl file itself. the file > will > not validate without the import explicitly listed there, saying the type > is > not declared as an event...) > > Here is the Java code: > > ResourceChangeScannerConfiguration sconf = ResourceFactory > .getResourceChangeScannerService() > .newResourceChangeScannerConfiguration(); > sconf.setProperty("drools.resource.scanner.interval", > "20"); > > ResourceFactory.getResourceChangeScannerService().configure(sconf); > > KnowledgeBaseConfiguration config = KnowledgeBaseFactory > .newKnowledgeBaseConfiguration(); > config.setOption(EventProcessingOption.STREAM); > > KnowledgeAgentConfiguration aconf = KnowledgeAgentFactory > .newKnowledgeAgentConfiguration(); > aconf.setProperty("drools.agent.scanDirectories", "true"); > aconf.setProperty("drools.agent.scanResources", "true"); > aconf.setProperty("drools.agent.newInstance", "false"); > KnowledgeBase kbase = > KnowledgeBaseFactory.newKnowledgeBase(config); > KnowledgeAgent kagent = > KnowledgeAgentFactory.newKnowledgeAgent( > "drools agent", kbase, aconf); > > String urlString = > " > http://localhost:8080/drools-guvnor/org.drools.guvnor.Guvnor/package/droo... > "; > try { > URL url = new URL(urlString); > UrlResource urlResource = (UrlResource) > ResourceFactory > .newUrlResource(url); > urlResource.setBasicAuthentication("enabled"); > urlResource.setUsername("John"); > urlResource.setPassword(""); > kagent.applyChangeSet(urlResource); > } catch (Exception e) { > System.out.println("Caught exception: " + > e.getMessage()); > e.printStackTrace(); > } > > ResourceFactory.getResourceChangeNotifierService().start(); > ResourceFactory.getResourceChangeScannerService().start(); > > StatefulKnowledgeSession ksession = > kbase.newStatefulKnowledgeSession(); > System.out.println("Initialize drools complete"); > > SimpleType simp = new SimpleType(); > simp.setNumber(5); > > ksession.insert(simp); > > Thanks, > John > > -- > View this message in context: > http://drools.46999.n3.nabble.com/NPE-on-fact-insertion-if-rule-has-slidi... > Sent from the Drools: User forum mailing list archive at Nabble.com. > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users >

Interesting... I have no idea why the KnowledgeBuilder would compile the DRL differently than the KnowledgeAgent, but I don't think I had this problem in 5.1.1.

I'm up and running now with the type fully declared in DRL and I can live with that. Thanks for looking into this. -- View this message in context: http://drools.46999.n3.nabble.com/NPE-on-fact-insertion-if-rule-has-slidi... Sent from the Drools: User forum mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

There's a bug in the incremental build as done by the KnowledgeAgent. If the KA configuration property drools.agent.newInstance is set to false, some type information is not put into the new KBase.

This is fixed in master. Will be in 3.1 final release. Edson 2011/10/7 mike9322 <michael.melton.ctr(a)navy.mil&gt; > > laune wrote: > > > > There's a bug in the incremental build as done by the KnowledgeAgent. If > > the > > KA configuration property drools.agent.newInstance is set to false, some > > type information is not put into the new KBase. > > > > I added the following comment to the JIRA related to this issue > (https://issues.jboss.org/browse/JBRULES-3145). Cross-posting here in > case > anyone else is having the issue and arrives here via Google like I did. > > "I am seeing the same behavior with my KA newInstance = true. I was able > to > workaround it by ensuring that my event POJOs are defined in the same > package as my rules. > > In other words, this DOES NOT work: > Rule package: com.example.rules > POJO package: com.example.rules.model (import statements included in DRL) > > This DOES work: > Rule package: com.example.rules > POJO package: com.example.rules (no import statements required) > > I did not have to move my event declaration to my DRL; they are still > POJOs. > I would prefer to have my POJOs in their own package but I can live with > this workaround for now." > > Mike > > > -- > View this message in context: > http://drools.46999.n3.nabble.com/NPE-on-fact-insertion-if-rule-has-slidi... > Sent from the Drools: User forum mailing list archive at Nabble.com. > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > -- Edson Tirelli JBoss Drools Core Development JBoss by Red Hat @ www.jboss.com _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users