[jboss-user] [jBPM] - NullPointerException problem when console tried to start new sub process, triggered by signal sent from async task

Bruce Cui [http://community.jboss.org/people/brucecui] created the discussion "NullPointerException problem when console tried to start new sub process, triggered by signal sent from async task" To view the discussion, visit: http://community.jboss.org/message/613255#613255 -------------------------------------------------------------- I know the subject is not quite clear. But problem itself does look that complex to me. Here is a background brief: I tried to use jBPM to drive some backend batch processes, which basically requires multi-threading. After struggling with various problems, asking around in the forum, changing and rebuilding source codes, I finally came to this stage: the console can now pass ksession(actually kruntime) to my self-defined work item handlers, and I can trigger the event by calling ksession's signal method with return value to the processInstance. This was suppose to be a maybe not perfect, but at least a working solution. But problems just come after another. Now I found that once the process contains sub process, it would throw out NullPointerException at the point when trying to add the sub process to persistance: "org.jbpm.persistence.processinstance.JPAProcessInstanceManager.addProcessInstance(JPAProcessInstanceManager.java:37)". Another question is, I found that when I called the signalEvent method of the ksession, it actually took over the process and run the rest in this thread. So, say if I have a infinite loop, and an async task runs every round, and an signal event starts after it waiting for return event. If the task calls the signalEvent method every time, once a new thread takes over the process, will the old thread end? Or it will keep accumulating? Below is the log output of the first problem: 2011-07-04 19:13:01,092 INFO  [STDOUT] (Thread-107) kruntime: org.drools.impl.StatefulKnowledgeSessionImpl@7b2b39 2011-07-04 19:13:01,092 INFO  [STDOUT] (Thread-107) process: WorkflowProcessInstance8 [processId=com.xxxx.CustomerLoader,state=1] 2011-07-04 19:13:01,092 INFO  [STDOUT] (Thread-107) process instance id: 8 2011-07-04 19:13:01,092 INFO  [STDOUT] (Thread-107) File collector done. Signal out 2011-07-04 19:13:01,107 INFO  [STDOUT] (Thread-107) Collector Event Received 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107) Exception in thread "Thread-107" 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107) org.drools.RuntimeDroolsException: Unexpected exception executing action org.jbpm.process.instance.event.DefaultSignalManager$SignalProcessInstanceAction@c5ab84 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.drools.common.AbstractWorkingMemory.executeQueuedActions(AbstractWorkingMemory.java:996) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.drools.impl.StatefulKnowledgeSessionImpl.executeQueuedActions(StatefulKnowledgeSessionImpl.java:845) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.process.instance.event.DefaultSignalManager.signalEvent(DefaultSignalManager.java:89) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.process.instance.ProcessRuntimeImpl.signalEvent(ProcessRuntimeImpl.java:359) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.drools.impl.StatefulKnowledgeSessionImpl.signalEvent(StatefulKnowledgeSessionImpl.java:327) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at com.sample.FileCollector.run(FileCollector.java:74) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107) Caused by: java.lang.NullPointerException 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.persistence.processinstance.JPAProcessInstanceManager.addProcessInstance(JPAProcessInstanceManager.java:37) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.process.instance.AbstractProcessInstanceFactory.createProcessInstance(AbstractProcessInstanceFactory.java:36) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.process.instance.ProcessRuntimeImpl.startProcess(ProcessRuntimeImpl.java:168) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.process.instance.ProcessRuntimeImpl.createProcessInstance(ProcessRuntimeImpl.java:140) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.process.instance.ProcessRuntimeImpl.startProcess(ProcessRuntimeImpl.java:121) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.drools.common.AbstractWorkingMemory.startProcess(AbstractWorkingMemory.java:1095) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.drools.impl.StatefulKnowledgeSessionImpl.startProcess(StatefulKnowledgeSessionImpl.java:306) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.node.SubProcessNodeInstance.internalTrigger(SubProcessNodeInstance.java:121) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.impl.NodeInstanceImpl.trigger(NodeInstanceImpl.java:122) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.impl.NodeInstanceImpl.triggerConnection(NodeInstanceImpl.java:185) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.node.SplitInstance.internalTrigger(SplitInstance.java:129) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.impl.NodeInstanceImpl.trigger(NodeInstanceImpl.java:122) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.impl.NodeInstanceImpl.triggerConnection(NodeInstanceImpl.java:185) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.impl.NodeInstanceImpl.triggerCompleted(NodeInstanceImpl.java:150) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.node.JoinInstance.triggerCompleted(JoinInstance.java:152) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.node.JoinInstance.internalTrigger(JoinInstance.java:52) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.impl.NodeInstanceImpl.trigger(NodeInstanceImpl.java:122) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.impl.NodeInstanceImpl.triggerConnection(NodeInstanceImpl.java:185) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.node.SplitInstance.internalTrigger(SplitInstance.java:129) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.impl.NodeInstanceImpl.trigger(NodeInstanceImpl.java:122) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.impl.NodeInstanceImpl.triggerConnection(NodeInstanceImpl.java:185) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.impl.NodeInstanceImpl.triggerCompleted(NodeInstanceImpl.java:150) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.node.JoinInstance.triggerCompleted(JoinInstance.java:152) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.node.JoinInstance.internalTrigger(JoinInstance.java:52) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.impl.NodeInstanceImpl.trigger(NodeInstanceImpl.java:122) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.impl.NodeInstanceImpl.triggerConnection(NodeInstanceImpl.java:185) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.impl.NodeInstanceImpl.triggerCompleted(NodeInstanceImpl.java:150) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.node.ActionNodeInstance.triggerCompleted(ActionNodeInstance.java:55) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.node.ActionNodeInstance.internalTrigger(ActionNodeInstance.java:51) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.impl.NodeInstanceImpl.trigger(NodeInstanceImpl.java:122) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.impl.NodeInstanceImpl.triggerConnection(NodeInstanceImpl.java:185) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.impl.NodeInstanceImpl.triggerCompleted(NodeInstanceImpl.java:150) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.node.ActionNodeInstance.triggerCompleted(ActionNodeInstance.java:55) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.node.ActionNodeInstance.internalTrigger(ActionNodeInstance.java:51) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.impl.NodeInstanceImpl.trigger(NodeInstanceImpl.java:122) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.impl.NodeInstanceImpl.triggerConnection(NodeInstanceImpl.java:185) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.impl.NodeInstanceImpl.triggerCompleted(NodeInstanceImpl.java:150) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.node.EventNodeInstance.triggerCompleted(EventNodeInstance.java:66) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.node.EventNodeInstance.signalEvent(EventNodeInstance.java:50) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.workflow.instance.impl.WorkflowProcessInstanceImpl.signalEvent(WorkflowProcessInstanceImpl.java:353) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.jbpm.process.instance.event.DefaultSignalManager$SignalProcessInstanceAction.execute(DefaultSignalManager.java:117) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           at org.drools.common.AbstractWorkingMemory.executeQueuedActions(AbstractWorkingMemory.java:994) 2011-07-04 19:13:01,138 ERROR [STDERR] (Thread-107)           ... 5 more -------------------------------------------------------------- Reply to this message by going to Community [http://community.jboss.org/message/613255#613255] Start a new discussion in jBPM at Community [http://community.jboss.org/choose-container!input.jspa?contentType=1&...]