I added that but it was asking to define getkbase().So I manupulated the code.Kindly have a look and advice me that how can I correct it.

Also tell me how can I test this concept.Where to find out the database in which the details are stored.

For your reference the code is as below:

package sample;
import org.drools.KnowledgeBase;
import org.drools.KnowledgeBaseFactory;
import org.drools.builder.KnowledgeBuilder;
import org.drools.builder.KnowledgeBuilderFactory;
import org.drools.builder.ResourceType;
import org.drools.io.ResourceFactory;
import org.drools.persistence.jpa.JPAKnowledgeService;
import org.drools.runtime.StatefulKnowledgeSession;
import org.jbpm.process.audit.JPAWorkingMemoryDbLogger;
import org.jbpm.test.JBPMHelper;

public class historyLog  {

/**
  * @param args
  */
public static void main(String[] args)  throws Exception {
  // TODO Auto-generated method stub
  //JBPMHelper.startH2Server();
  //JBPMHelper.setupDataSource();
 
  //EntityManagerFactory emf =
  //    Persistence.createEntityManagerFactory( "org.jbpm.persistence.jpa" );

  org.drools.runtime.Environment env = KnowledgeBaseFactory.newEnvironment();
  KnowledgeBase kbase = readKnowledgeBase();
 
  //StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession();
  //JPAWorkingMemoryDbLogger logger = new JPAWorkingMemoryDbLogger(ksession);

  StatefulKnowledgeSession ksession = JPAKnowledgeService.newStatefulKnowledgeSession(kbase, null, env);
  JPAWorkingMemoryDbLogger jbpmLogger = new JPAWorkingMemoryDbLogger(ksession);
  ksession.startProcess("sample.bpmn.hh"); 
  jbpmLogger.dispose();

}

private static KnowledgeBase readKnowledgeBase() throws Exception {
  KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
  kbuilder.add(ResourceFactory.newClassPathResource("demo2.bpmn"), ResourceType.BPMN2);
  return kbuilder.newKnowledgeBase();
}

}

But can I use the inbuilt H2 database? And in the user guide that I had doesn't mention anything regarding the creatio of the database.Can you share the user guide or the link if possible.And also let me know whether my approach is correct or not.