topic Re: sending specific signal to custom behavior task in Alfresco Archive

sending specific signal to custom behavior task

miran — Mon, 18 Apr 2016 21:48:35 GMT

Hi, I got following problem - I use custom behavior to do some async work and I need to notify the process instance with information how the async task ended - I am using following codeublic class MyAsyncTask implements SignallableActivityBehavior { // something that takes long time (sending J

Re: sending specific signal to custom behavior task

martin_grofcik — Tue, 19 Apr 2016 06:54:07 GMT

Hi,

You can follow your first approach with using


  /**
   * Sends an external trigger to an activity instance that is waiting inside
   * the given execution.
   *
   * @param executionId
   *          id of execution to signal, cannot be null.
   * @param processVariables
   *          a map of process variables
   * @throws ActivitiObjectNotFoundException
   *           when no execution is found for the given executionId.
   */
  void signal(String executionId, Map<String, Object> processVariables);

example:
org.activiti.engine.test.api.runtime.RuntimeServiceTest#testSignalWithProcessVariables
or you can create message start event to wait on runtimeService.signalEventReceived(eventName, pid, vars);example:org.activiti.engine.test.bpmn.event.signal.SignalEventTest#testSignalStartEventFromAPI
Regards
Martin

Re: sending specific signal to custom behavior task

rajivmoghe — Tue, 19 Apr 2016 14:51:19 GMT

Hello Martin,

For some reason, it does not seem to work for me. I took the SignalEventTest xml and tried to run that on my spring-boot-activiti installation, and signalled it using the ReST API (PUT /runtime/executions/{exId} ) , but it gave the following issues:

When using the signal method,
Payload:


{
  "action":"signal",
  "signalName":"waitsig"
}

It fails with :


java.lang.NullPointerException: null
 at org.activiti.engine.impl.persistence.entity.ExecutionEntity.signal(ExecutionEntity.java:404)
 at org.activiti.engine.impl.cmd.SignalCmd.execute(SignalCmd.java:43)
 at org.activiti.engine.impl.cmd.NeedsActiveExecutionCmd.execute(NeedsActiveExecutionCmd.java:55)
 at org.activiti.engine.impl.interceptor.CommandInvoker.execute(CommandInvoker.java:24)
 at org.activiti.engine.impl.interceptor.CommandContextInterceptor.execute(CommandContextInterceptor.java:57)
 at org.activiti.spring.SpringTransactionInterceptor$1.doInTransaction(SpringTransactionInterceptor.java:47)
 at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:133)
 at org.activiti.spring.SpringTransactionInterceptor.execute(SpringTransactionInterceptor.java:45)
 at org.activiti.engine.impl.interceptor.LogInterceptor.execute(LogInterceptor.java:31)
 at org.activiti.engine.impl.cfg.CommandExecutorImpl.execute(CommandExecutorImpl.java:40)
 at org.activiti.engine.impl.cfg.CommandExecutorImpl.execute(CommandExecutorImpl.java:35)
 at org.activiti.engine.impl.RuntimeServiceImpl.signal(RuntimeServiceImpl.java:231)
 at org.activiti.rest.service.api.runtime.process.ExecutionResource.performExecutionAction(ExecutionResource.java:49)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
 at java.lang.reflect.Method.invoke(Method.java:497)

While with the payload of:


{
  "action":"signalEventReceived",
  "signalName":"waitsig",
}

It responds with : "message": "Execution '17' has not subscribed to a signal event with name 'waitsig'.",
I've been trying to figure this one out for a while now too, but unable to make a headway.

Is there something really simple that we are missing here?

I've attached the bpmn xml file with this.

Re: sending specific signal to custom behavior task

miran — Tue, 19 Apr 2016 15:22:47 GMT

Martin, thanks a lot for your quick response. It worked for me. The trick was in using method

<code>void signal(String executionId, Map<String, Object> processVariables);</code>
instead of
<code>void signalEventReceived(String, String, Map<String, Object>);</code>

I must have missed it totally!

Re: sending specific signal to custom behavior task

rajivmoghe — Tue, 19 Apr 2016 15:53:55 GMT

@Miran,
Would you be able to share the (sanitised) caller code, from which you call the signal method?

@Martin: What could be the reason for the null pointer, when calling the signal through ReST API?

Re: sending specific signal to custom behavior task

martin_grofcik — Wed, 20 Apr 2016 06:22:44 GMT

Hi Rajiv,

Create jUnit test please
https://forums.activiti.org/content/sticky-how-write-unit-test

Regards
Martin

Re: sending specific signal to custom behavior task

ptica — Wed, 20 Apr 2016 13:38:48 GMT

Hi!
I'm curious about the <code>org.activiti.engine.test.bpmn.event.signal.SignalEventTest#testSignalStartEventFromAPI</code> example

it is not included in the release package, (I've looked into the lib/activiti-engine.jar) right? I've downloaded it from github, but I still struggle to visualize it, as bpmn di is not included there, I've used the Eclipse Designer to load it, but upon autolayout and import into Explorer only one task is shown, even though when I peak into the xml, there is lot more to it.

Is that the expected behaviour?
thank you!

Re: sending specific signal to custom behavior task

martin_grofcik — Thu, 21 Apr 2016 11:56:59 GMT

Hi Ptica,

it is not included in the release package, (I've looked into the lib/activiti-engine.jar) right?

release does not contain tests. Download project from source repository.

bpmn di is only presentation layer - not needed for the engine to execute the tests. Usually test processes are so simple that they can be easily understandable from bpmn xml.

Is that the expected behaviour?

May be designer could create better default diagram layout…., but I would not waste time to fix that. Just understand the process from the bpm.xml

Regards
Martin

Re: sending specific signal to custom behavior task

rajivmoghe — Thu, 21 Apr 2016 12:31:45 GMT

Hi Martin,

Thanks for the pointer… as I started to create the test, I realized where I was going wrong.
Turns out that I was using the wrong execution (processInstance != execution when a boundary event is encountered on an activity, see here and here) on the void signalEventReceived(String, String, Map<String, Object>); call.

I will create and post the test for the void signal(String executionId, Map<String, Object> processVariables); piece soon.