[rules-users] Null pointer exception after adding When condtion in Guvunor

[JimK]

Using the latest JBPM installer demo setup, I have a simple program. It has
an object called person with a name and a salary.  In guvonor there is a
simple rule that I scaled back from the original to try to see what is
happening.  If I have a condition (salary >= 5000) it gives a null
exception, if I remove the condition it works fine. The new fact is inserted
and I can see it from my program.  Just starting experimenting with guvonor
and have been following the threads on changeset but don't have a complete
grasp on it yet.

Thanks in advance,
Jim K.

rule "PersonWIthHighIncome" 
     no-loop true 
     dialect "mvel" 
     when 
         Person( salary >= 5000 ) 
     then 
         Person fact0 = new Person(); 
         fact0.setName( "Joe" ); 
         fact0.setSalary( 34465 ); 
         insert(fact0 ); 
 end 
 
This results in the following exception:
java.lang.NullPointerException
	at
org.drools.impl.KnowledgeBaseImpl.addKnowledgePackages(KnowledgeBaseImpl.java:148)
	at
org.drools.agent.impl.KnowledgeAgentImpl.addResourcesToKnowledgeBase(KnowledgeAgentImpl.java:1016)
	at
org.drools.agent.impl.KnowledgeAgentImpl.rebuildResources(KnowledgeAgentImpl.java:785)
	at
org.drools.agent.impl.KnowledgeAgentImpl.buildKnowledgeBase(KnowledgeAgentImpl.java:657)
	at
org.drools.agent.impl.KnowledgeAgentImpl.applyChangeSet(KnowledgeAgentImpl.java:190)
	at
org.drools.agent.impl.KnowledgeAgentImpl.applyChangeSet(KnowledgeAgentImpl.java:169)
	at simpleBank.SimpleBank.createKnowledgeBase(SimpleBank.java:64)
	at simpleBank.SimpleBank.main(SimpleBank.java:27)

Code calling the package

package simpleBank;

import java.util.ArrayList;
import java.util.Iterator;

import org.drools.KnowledgeBase;
import org.drools.KnowledgeBaseFactory;
import org.drools.agent.KnowledgeAgent;
import org.drools.agent.KnowledgeAgentConfiguration;
import org.drools.agent.KnowledgeAgentFactory;
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;

public class SimpleBank {
		
		public static void main(String[] args) {
	        try {
	            // load up the knowledge base
	            //KnowledgeBase kbase = readKnowledgeBase();
	            KnowledgeBase kbase = createKnowledgeBase();
	            StatefulKnowledgeSession ksession =
kbase.newStatefulKnowledgeSession();
	            //KnowledgeRuntimeLogger logger =
KnowledgeRuntimeLoggerFactory.newFileLogger(ksession, "test");
	            KnowledgeRuntimeLogger logger =
KnowledgeRuntimeLoggerFactory.newThreadedFileLogger(ksession, "Test2", 1);
	            
	            
	            // go ! insert one person
				Person person = new Person();
				person.setSalary((long) 6000);
				person.setName("Jim");
				System.out.println(person.getName());
				ksession.insert(person);

				assertTrue(ksession.getFactCount() == 1);
				ksession.fireAllRules();
				// rules should have added another fact
				assertTrue(ksession.getFactCount() != 1);
				ArrayList<Person> listoffacts = new ArrayList(ksession.getObjects());
				System.out.println(listoffacts.size());
				Iterator<Person> itr = listoffacts.iterator();
			    while (itr.hasNext()){
			    	Person element = itr.next();
			    	System.out.println(element.getName() + ":" +
element.getSalary().toString());
			    }
	            logger.close();
	        } catch (Throwable t) {
	            t.printStackTrace();
	        }
		}
		

	    
		private static KnowledgeBase createKnowledgeBase() throws Exception{
			 KnowledgeAgentConfiguration kaconf =
KnowledgeAgentFactory.newKnowledgeAgentConfiguration();
			 kaconf.setProperty( "drools.agent.scanDirectories", "false" );
			 KnowledgeAgent kagent = KnowledgeAgentFactory.newKnowledgeAgent( "test
agent", kaconf );
			 
			 kagent.applyChangeSet(ResourceFactory.newUrlResource(
"http://localhost:8080/drools-guvnor/org.drools.guvnor.Guvnor/package/SalesModel/LATEST/ChangeSet.xml"
));
//			 kagent.applyChangeSet(
ResourceFactory.newClassPathResource("ChangeSet.xml"));
			 return kagent.getKnowledgeBase();
		}

	    private static void assertTrue(boolean b) {
			if (b)
			{
				System.out.println("Good number of facts");
			}
			else
			{
				System.out.println("Bad number of facts");
			}
			}

		
	}


 


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