[jboss-jira] [JBoss JIRA] Commented: (JBRULES-1982) NullPointerException when executing rule sample
Hrvoje Habjanic (JIRA)
jira-events at lists.jboss.org
Thu Mar 12 05:48:23 EDT 2009
[ https://jira.jboss.org/jira/browse/JBRULES-1982?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12456857#action_12456857 ]
Hrvoje Habjanic commented on JBRULES-1982:
------------------------------------------
Hi!
Thanks on comment, but should not be there more understoodable error or message? NPE is not nice to see ... And should not there be some check if compiling fails ...
I did manage to sort some stuff out. First, it is a _mess_ to split packages to different jars. This should not be done, it is a bad progamer practice.
Next, not all bundles are needed. It will work with only drools-api, drools-core and drools-compiler packed together. It also reguires antlr newer version than existing in springsource, so anltr jar must be packed in bundle.
And finally, "java" dialect does not work, but "mvel" dialect is working without problems (of course, mvel jar must be also bundle-ized and put into ss repository).
In case of complex use between bundles, on initialization of knowledge base, builder and resource, classpath loader _must_ be supplied. I hope this will help others wishing to use drools 5 in sprinsource server.
All this is done on M5. I will try RC1 and repost if there is any changes.
H.
> NullPointerException when executing rule sample
> -----------------------------------------------
>
> Key: JBRULES-1982
> URL: https://jira.jboss.org/jira/browse/JBRULES-1982
> Project: JBoss Drools
> Issue Type: Bug
> Security Level: Public(Everyone can see)
> Affects Versions: 5.0.0.M5
> Environment: Springsource DM Server v.1.0.1, all jar-s bundled together in single jar file, then converted to bundle using bnd utility
> Reporter: Hrvoje Habjanic
> Assignee: Mark Proctor
> Priority: Minor
>
> 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.
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