Tun Mang [http://community.jboss.org/people/tunmang] created the discussion "in jbpm 4.3, timer's event listener throws exception on ExecuteEventListener.java:68." To view the discussion, visit: http://community.jboss.org/message/554894#554894 -------------------------------------------------------------- Hi there, Follow the example described in "jbpm-4.3/doc/devguide/html_single/index.html#timer", the following is what we have done:     (1) in the event listener, we call executeJob:   public void notify(EventListenerExecution execution)   {       String aId   = execution.getId();     String aName = execution.getName();        out("===============================");     out("timer handler: (timeout) event (" + aId + ").");     out("===============================");     ProcessInstance processInstance = (ProcessInstance) execution.getProcessInstance();        ManagementService managementService = EnvironmentImpl.getFromCurrent(ManagementService.class);        JobQuery jobQuery = managementService.createJobQuery();        JobQuery timerQuery = jobQuery.timers();        JobQuery ptQuery = timerQuery.processInstanceId( processInstance.getId() );         List<Job> jobList = ptQuery.list();        Job foundJob = null;          for(int ii=0 ; ii < jobList.size(); ii++)     {       Job jbpmJob = jobList.get(ii);                Execution jobExcu = jbpmJob.getExecution();           String bId   = jobExcu.getId();       String bName = jobExcu.getName();            if( ! bId.equals(aId) || ! bName.equals(aName) )         continue;                 foundJob = jbpmJob;       break;     }         if( foundJob == null )     {       err("cannot find a matched timer object in external db: (execId: " + aId + "), (name: " + aName + ").");       return;     }     out("found a matched timer object in external db: (execId: " + aId + "), (name: " + aName + "), (timerId: " + foundJob.getId() + ").");           managementService.executeJob( foundJob.getId() );     }   (2) in the process definition, we linked it with the timer:     <state g="222,123,147,40" name="generate-file">       <on event="timeout">         <timer duedate="10 seconds"/>       <event-listener class="basicfive.TestTimerHandler">           <field name="msg"><string value="entered the (generate-file) state node."/></field>         </event-listener>         </on>       <on event="start">         <event-listener class="basicfive.TestJobMakeRequestHandler">           <field name="msg"><string value="entered the (generate-file) state node."/></field>         </event-listener>         </on>       <transition g="-71,-15" name="timeout" to="remove-file">              </transition>              </state>   (3) When start the process instance, and after it reaches the handler, it always throws the following exeptions: 10-07-28/17:01:17 DEBUG [basicfive.TestTimerHandler]: (AP) =============================== 10-07-28/17:01:17 DEBUG [basicfive.TestTimerHandler]: (AP) timer handler: (timeout) event (test_Timer_1.680001.generate-file). 10-07-28/17:01:17 DEBUG [basicfive.TestTimerHandler]: (AP) =============================== 10-07-28/17:01:17 DEBUG [basicfive.TestTimerHandler]: (AP) found a matched timer object in external db: (execId: test_Timer_1.680001.generate-file), (name: generate-file), (timerId: 680004). 10-07-28/17:01:17 DEBUG [basicfive.TestTimerHandler]: (AP) leaving event fired for timer object in external db: (id: test_Timer_1.680001.generate-file), (name: generate-file). ### EXCEPTION ########################################### 17:01:17,161 SEV       | [ExecuteJobCmd] exception while executing 'timer[680004|2010-07-28 17:01:15,000|timeout]' java.lang.NullPointerException at org.jbpm.pvm.internal.model.op.ExecuteEventListener.perform(ExecuteEventListener.java:68) at org.jbpm.pvm.internal.model.ExecutionImpl.performAtomicOperationSync(ExecutionImpl.java:678) at org.jbpm.pvm.internal.model.ExecutionImpl.performAtomicOperation(ExecutionImpl.java:638) at org.jbpm.pvm.internal.model.ExecutionImpl.fire(ExecutionImpl.java:585) at org.jbpm.pvm.internal.model.ExecutionImpl.fire(ExecutionImpl.java:575) ...... How do we resolve this problem ? Thanks a lot for your help in advance. -------------------------------------------------------------- Reply to this message by going to Community [http://community.jboss.org/message/554894#554894] Start a new discussion in jBPM at Community [http://community.jboss.org/choose-container!input.jspa?contentType=1&...]