Task Listener throws null error

[amruta_w]

Hello All,

I have written task listener to get the users from candidate group I'm trying to call the following method 

List<User> users = userService.findUsersForGroup(Long.parseLong(groupId), "", 0, 1000);

System.out.println("users=" + users.get(0).getEmail());

It is throwing error as null, even though I have users in group.

Can anyone please tell me please why i'm getting null.

Thanks & Regards

Amruta Wandakar

[jljwoznica]

Can you take a look at this? https://docs.alfresco.com/process-services1.6/topics/user_info_bean_userinfobean.html

[abbask01]

Can you help us with exception stack trace?

[amruta_w]

---

@abbask01 wrote:

Can you help us with exception stack trace?

---

I have got following error - unable to post complete error trace

ERROR org.activiti.engine.impl.interceptor.CommandContext  - Error while closing command context
org.activiti.engine.ActivitiException: Exception while invoking TaskListener: Exception while invoking TaskListener: null
        at org.activiti.engine.impl.persistence.entity.TaskEntity.fireEvent(TaskEntity.java:742)
        at org.activiti.engine.impl.bpmn.behavior.UserTaskActivityBehavior.execute(UserTaskActivityBehavior.java:212)
        at org.activiti.engine.impl.pvm.runtime.AtomicOperationActivityExecute.execute(AtomicOperationActivityExecute.java:60)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:671)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:666)
        at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerStart.eventNotificationsCompleted(AtomicOperationTransitionNotifyListenerStart.java:52)
        at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:58)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:671)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:666)
        at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:51)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:671)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:666)
        at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionCreateScope.execute(AtomicOperationTransitionCreateScope.java:49)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:671)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:666)
        at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerTake.execute(AtomicOperationTransitionNotifyListenerTake.java:80)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:671)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:666)
        at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionDestroyScope.execute(AtomicOperationTransitionDestroyScope.java:116)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:671)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:666)
        at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerEnd.eventNotificationsCompleted(AtomicOperationTransitionNotifyListenerEnd.java:35)
        at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:58)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:671)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:666)
        at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:51)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:671)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:666)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.take(ExecutionEntity.java:483)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.take(ExecutionEntity.java:461)
        at org.activiti.engine.impl.bpmn.behavior.ExclusiveGatewayActivityBehavior.leave(ExclusiveGatewayActivityBehavior.java:83)
        at org.activiti.engine.impl.bpmn.behavior.FlowNodeActivityBehavior.execute(FlowNodeActivityBehavior.java:36)
        at org.activiti.engine.impl.pvm.runtime.AtomicOperationActivityExecute.execute(AtomicOperationActivityExecute.java:60)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:671)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:666)
        at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerStart.eventNotificationsCompleted(AtomicOperationTransitionNotifyListenerStart.java:52)
        at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:58)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:671)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:666)
        at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:51)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:671)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:666)
        at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionCreateScope.execute(AtomicOperationTransitionCreateScope.java:49)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:671)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:666)
        at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerTake.execute(AtomicOperationTransitionNotifyListenerTake.java:80)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:671)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:666)
        at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionDestroyScope.execute(AtomicOperationTransitionDestroyScope.java:116)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:671)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:666)
        at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerEnd.eventNotificationsCompleted(AtomicOperationTransitionNotifyListenerEnd.java:35)
        at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:58)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:671)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:666)
        at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:51)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:671)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:666)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.take(ExecutionEntity.java:483)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.take(ExecutionEntity.java:461)
        at org.activiti.engine.impl.bpmn.behavior.BpmnActivityBehavior.performOutgoingBehavior(BpmnActivityBehavior.java:140)
        at org.activiti.engine.impl.bpmn.behavior.BpmnActivityBehavior.performDefaultOutgoingBehavior(BpmnActivityBehavior.java:66)
        at org.activiti.engine.impl.bpmn.behavior.FlowNodeActivityBehavior.leave(FlowNodeActivityBehavior.java:44)
 

[gkorman125]

Were you able to get to the source of this issue?  I'm hitting a very simular issue when a task is requeued.

[abbask01]

the stacktrace you provided does not mention your code any where. have you checked the tasklistener config is proper? can you provide the whole trace?

[amruta_w]

The whole stack trace unable to provide here and i didn't got the root cause, if you have resolved please let me know. thanks in advance.

[gkorman125]

I was able to resolve this issue.  The "assignment" event fires on requeue.  This caused a the script code that was attempting to set a process variable for the assignee first+last name and email to fail with the null error.