PropagateError in triggerable service task with expression

Flowable Engine
1

Hi,

I have a triggerable service task which uses an expression to start an asynchronous background job, e.g.

<serviceTask id="init-job" name="init my async Job" activiti:async="true" activiti:expression="${bean.requestAsyncJob()}" activiti:resultVariableName="jobId" activiti:triggerable="true">
  <extensionElements>
    <activiti:executionListener event="end" delegateExpression="${evaluateCallback}" />
    <activiti:mapException errorCode="CODE-001">java.lang.RuntimeException</activiti:mapException>
  </extensionElements>
</serviceTask>

I want to catch an error (e.g. RuntimeException) by an Error Boundary Event attached to my init-job Service Task. This works, when the requestAsyncJob() Method throws some RuntimException.

But since it’s asynchronous, it’s also possible, that the external sytems sends us after the method completion a failure (we trigger() then the execution with a variable status=error), and we would also like to enter the Error Boundary Event. Currently we have some ‘Callback’ ExecutionListeners for examing the status variable and throwing exceptions when status=error so that the execution stops.

But throwing the RuntimeException in the ExecutionListener does not propagate the error, also calling ErrorPropagation.propagateError(“some-error”, execution) inside there does not work.

Any ideas how to come around this issue by using expressions (not delegateExpressions)?

Regards, Björn

2

ok, no reply, not sure, whether my question was unclear or too complicated !?

So, I found following working solution:

I extend org.flowable.engine.impl.bpmn.behavior.ServiceTaskExpressionActivityBehavior and overwrite trigger() by implementing the Error-propagation inside there.

Next problem: How to create a DeadLetter Job, when the callback is reportet as error (this does not happen)?

I tried following code, which is executed without exception but the DB table ACT_RU_DEADLETTER_JOB is empty:

public void trigger(DelegateExecution execution, String signalName, Object signalData) {
    .....
    JobService jobService = CommandContextUtil.getJobService();
    DeadLetterJobEntity job = jobService.createDeadLetterJob();
    job.setExecutionId(execution.getId());
    job.setProcessInstanceId(execution.getProcessInstanceId());
    job.setProcessDefinitionId(execution.getProcessDefinitionId());
    job.setElementId(execution.getCurrentFlowElement().getId());
    job.setElementName(execution.getCurrentFlowElement().getName());
    // Inherit tenant id (if applicable)
    if(execution.getTenantId() != null) {
        job.setTenantId(execution.getTenantId());
    }
    jobService.insertDeadLetterJob(job);

Any idea, why the DB-Table is not populated? Transaction not committed?

Hoping for an answer this time,
Björn

3

I agree. If the error propagation isn’t done there, it should be added. I’ll check if I can add this to the code.

No, that code looks correct.

Can you enable debug logging and check whether either the deadletter job gets inserted (doubtful) or there is a transaction rollback? In the second case, the deadletter job should then be created in a post-rollback listener that you can attach to the currect TransactionContext (which you can retrieve via the Context class).

4

the problem was an exception thrown by me, so I guess it was caused by an rollback. I removed the throws part and it works now

would be great