[jboss-jira] [JBoss JIRA] Updated: (JBRULES-1982) NullPointerException when executing rule sample

Thu Feb 26 11:22:45 EST 2009

     [ https://jira.jboss.org/jira/browse/JBRULES-1982?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Hrvoje Habjanic updated JBRULES-1982:
-------------------------------------

    Description: 
Hi!

I have somewhat non-standard running environment - springsource sever. Because spring requires everything to be provided as bundle, i created drools bundle. I  unpacked (extract) all drools jar-s except drools-clips, drools-jsr94 and drools-process-enterprise into single directory, and then created one big jar. Then i converted this jar using bnd utility to bundle. Because springsource uses older antlr, i did copy antlr-runtime-3.1.1 into bundle, to classes inside use this version.

In eclipse i created new project, and created helloworld sample. I did manage successfully to execute RuleFlowTest! But, DroolsTest fails with:

[2009-02-26 17:18:35.245] server-dm-8                                                                    System.err E org.drools.runtime.rule.ConsequenceException: java.lang.NullPointerException
[2009-02-26 17:18:35.245] server-dm-8                                                                    System.err E 	at org.drools.runtime.rule.impl.DefaultConsequenceExceptionHandler.handleException(DefaultConsequenceExceptionHandler.java:23)
[2009-02-26 17:18:35.245] server-dm-8                                                                    System.err E 	at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:935)
[2009-02-26 17:18:35.245] server-dm-8                                                                    System.err E 	at org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:882)
[2009-02-26 17:18:35.246] server-dm-8                                                                    System.err E 	at org.drools.common.DefaultAgenda.fireAllRules(DefaultAgenda.java:1072)
[2009-02-26 17:18:35.246] server-dm-8                                                                    System.err E 	at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:616)
[2009-02-26 17:18:35.246] server-dm-8                                                                    System.err E 	at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:583)
[2009-02-26 17:18:35.246] server-dm-8                                                                    System.err E 	at org.drools.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:151)
[2009-02-26 17:18:35.246] server-dm-8                                                                    System.err E 	at com.sample.DroolsTest.main(DroolsTest.java:33)
[2009-02-26 17:18:35.246] server-dm-8                                                                    System.err E 	at com.sample.Runner.init(Runner.java:16)
[2009-02-26 17:18:35.247] server-dm-8                                                                    System.err E 	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[2009-02-26 17:18:35.247] server-dm-8                                                                    System.err E 	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
[2009-02-26 17:18:35.247] server-dm-8                                                                    System.err E 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
[2009-02-26 17:18:35.247] server-dm-8                                                                    System.err E 	at java.lang.reflect.Method.invoke(Method.java:597)
[2009-02-26 17:18:35.248] server-dm-8                                                                    System.err E 	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeCustomInitMethod(AbstractAutowireCapableBeanFactory.java:1414)
[2009-02-26 17:18:35.248] server-dm-8                                                                    System.err E 	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1375)
[2009-02-26 17:18:35.248] server-dm-8                                                                    System.err E 	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1335)
[2009-02-26 17:18:35.248] server-dm-8                                                                    System.err E 	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:473)
[2009-02-26 17:18:35.248] server-dm-8                                                                    System.err E 	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$1.run(AbstractAutowireCapableBeanFactory.java:409)
[2009-02-26 17:18:35.248] server-dm-8                                                                    System.err E 	at java.security.AccessController.doPrivileged(Native Method)
[2009-02-26 17:18:35.249] server-dm-8                                                                    System.err E 	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:380)
[2009-02-26 17:18:35.249] server-dm-8                                                                    System.err E 	at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:264)
[2009-02-26 17:18:35.249] server-dm-8                                                                    System.err E 	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
[2009-02-26 17:18:35.249] server-dm-8                                                                    System.err E 	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:261)
[2009-02-26 17:18:35.250] server-dm-8                                                                    System.err E 	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:185)
[2009-02-26 17:18:35.250] server-dm-8                                                                    System.err E 	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:164)
[2009-02-26 17:18:35.250] server-dm-8                                                                    System.err E 	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:429)
[2009-02-26 17:18:35.250] server-dm-8                                                                    System.err E 	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:728)
[2009-02-26 17:18:35.251] server-dm-8                                                                    System.err E 	at org.springframework.osgi.context.support.AbstractDelegatedExecutionApplicationContext.completeRefresh(AbstractDelegatedExecutionApplicationContext.java:288)
[2009-02-26 17:18:35.251] server-dm-8                                                                    System.err E 	at org.springframework.osgi.extender.internal.dependencies.startup.DependencyWaiterApplicationContextExecutor$CompleteRefreshTask.run(DependencyWaiterApplicationContextExecutor.java:145)
[2009-02-26 17:18:35.252] server-dm-8                                                                    System.err E 	at com.springsource.server.kernel.dm.ContextPropagatingTaskExecutor$2.run(ContextPropagatingTaskExecutor.java:82)
[2009-02-26 17:18:35.252] server-dm-8                                                                    System.err E 	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
[2009-02-26 17:18:35.252] server-dm-8                                                                    System.err E 	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
[2009-02-26 17:18:35.253] server-dm-8                                                                    System.err E 	at java.lang.Thread.run(Thread.java:619)
[2009-02-26 17:18:35.253] server-dm-8                                                                    System.err E Caused by: java.lang.NullPointerException
[2009-02-26 17:18:35.254] server-dm-8                                                                    System.err E 	at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:926)
[2009-02-26 17:18:35.254] server-dm-8                                                                    System.err E 	... 31 more

Drools file which is executed is:

package com.sample

import com.sample.DroolsTest.Message;

rule "Hello World"
	when
		m : Message( status == Message.HELLO, message : message )
	then
		System.out.println( "Ssssss" ); 
		m.setMessage( "Goodbye cruel world" );
		m.setStatus( Message.GOODBYE );
		update( m );
end

rule "GoodBye"
	when
		Message( status == Message.GOODBYE, message : message )
	then
		System.out.println( message );
end

And DroolsTest java is also unmodified:

package com.sample;

import org.drools.KnowledgeBase;
import org.drools.KnowledgeBaseFactory;
import org.drools.builder.KnowledgeBuilder;
import org.drools.builder.KnowledgeBuilderError;
import org.drools.builder.KnowledgeBuilderErrors;
import org.drools.builder.KnowledgeBuilderFactory;
import org.drools.builder.ResourceType;
import org.drools.io.ResourceFactory;
import org.drools.logger.KnowledgeRuntimeLogger;
import org.drools.logger.KnowledgeRuntimeLoggerFactory;
import org.drools.runtime.StatefulKnowledgeSession;

/**
 * This is a sample class to launch a rule.
 */
public class DroolsTest {

	public static final void main(String[] args) {
		try {
			// load up the knowledge base
			KnowledgeBase kbase = readKnowledgeBase();
			StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession();
			KnowledgeRuntimeLogger logger = KnowledgeRuntimeLoggerFactory.newFileLogger(ksession, "test");
			// go !
			Message message = new Message();
			message.setMessage("Hello World");
			message.setStatus(Message.HELLO);
			ksession.insert(message);
			ksession.fireAllRules();
			logger.close();
		} catch (Throwable t) {
			t.printStackTrace();
		}
	}

	private static KnowledgeBase readKnowledgeBase() throws Exception {
		KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
		kbuilder.add(ResourceFactory.newClassPathResource("Sample.drl"), ResourceType.DRL);
		KnowledgeBuilderErrors errors = kbuilder.getErrors();
		if (errors.size() > 0) {
			for (KnowledgeBuilderError error: errors) {
				System.err.println(error);
			}
			throw new IllegalArgumentException("Could not parse knowledge.");
		}
		KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase();
		kbase.addKnowledgePackages(kbuilder.getKnowledgePackages());
		return kbase;
	}

	public static class Message {

		public static final int HELLO = 0;
		public static final int GOODBYE = 1;

		private String message;

		private int status;

		public String getMessage() {
			return this.message;
		}

		public void setMessage(String message) {
			this.message = message;
		}

		public int getStatus() {
			return this.status;
		}

		public void setStatus(int status) {
			this.status = status;
		}

	}

}

I did try to browse trough source and try to find out what the problem could be, but at no avail.

  was:
Hi!