JBPM4.3结合规则器如何发布

在JBPM4.3中，如何将流程与规则器（drools）结合一起？如何部署。
<?xml version="1.0" encoding="UTF-8"?>
<process name="RulesDecision"> <start>
<transition to="isImportant" />
</start> <rules-decision name="isImportant">
<transition name="dunno" to="analyseManually" />
<transition name="important" to="processWithPriority" />
<transition name="irrelevant"
to="processWhenResourcesAvailable" />
</rules-decision> <state name="analyseManually" />
<state name="processWithPriority" />
<state name="processWhenResourcesAvailable" /></process>
程序为啥就在rules-decision节点，无法再继续了？其中执行到
/**
 * @author Tom Baeyens
 */
public class RulesDecisionActivity extends JpdlActivity {  private static final long serialVersionUID = 1L;  public void execute(ActivityExecution execution) throws Exception {
    String deploymentId = ((ExecutionImpl)execution).getProcessDefinition().getDeploymentId();
    KnowledgeBase knowledgeBase = RulesDeployer.getKnowledgeBase(deploymentId);    StatelessKnowledgeSession knowledgeSession = 
        knowledgeBase.newStatelessKnowledgeSession();
    
    ExecutionGlobals executionGlobals = new ExecutionGlobals(execution);
    knowledgeSession.getGlobals().setDelegate(executionGlobals);
    knowledgeSession.execute(execution);
    if (!executionGlobals.getOutcome().isDefined()) {
      execution.takeDefaultTransition();
    } else {
      execution.take(executionGlobals.getOutcome().get());
    }
  }
}这里时KnowledgeBase knowledgeBase = RulesDeployer.getKnowledgeBase(deploymentId);为空。有知道的朋友么？