Hi, I am a beginner to drools and am trying to integrate drools rules to java . Am doing this using changeset. Here's my piece of code: package edu.arizona; import org.drools.KnowledgeBase; import org.drools.agent.KnowledgeAgent; import org.drools.agent.KnowledgeAgentFactory; import org.drools.definition.type.FactType; import org.drools.io.Resource; import org.drools.io.ResourceFactory; import org.drools.runtime.StatefulKnowledgeSession; public class TestRest { public static void main(String[] args) throws InstantiationException,IllegalAccessException { StatefulKnowledgeSession ksession = null; KnowledgeBase kbase = readKnowledgeBase(); FactType factType = kbase.getFactType("edu.arizona", "result"); System.out.println (factType); Object obj = factType.newInstance(); factType.set(obj,"rawConcentration",150); ksession = kbase.newStatefulKnowledgeSession(); ksession.insert(obj); ksession.fireAllRules(); System.out.println(factType.get(obj,"rescode")); } private static KnowledgeBase readKnowledgeBase() { KnowledgeAgent kagent = KnowledgeAgentFactory.newKnowledgeAgent("LabAgent"); Resource changeset = ResourceFactory.newClassPathResource( "edu.arizona/lab-changeset.xml"); kagent.applyChangeSet(changeset); KnowledgeBase kbase = kagent.getKnowledgeBase(); kagent.dispose(); return kbase; } } When i run the application the System.out.println (factType) is printing as null. and getting Exception in thread "main" java.lang.NullPointerException at edu.arizona.TestRest.main(TestRest.java:20) What am i missing? Please help. Thanks, Kavitha. -- View this message in context: http://drools.46999.n3.nabble.com/Get-fact-type-returning-null-tp3667266p... 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