topic Re: How to do exception handling in Activiti v6.0.0 in Alfresco Forum

How to do exception handling in Activiti v6.0.0

nami — Mon, 23 Apr 2018 14:06:47 GMT

‌Hi I am new to Activiti Framework, Can someone please give information on how can we do exception handling in activiti v6.0.0 . Please attach a sample bpmn xml file with exception as a service task, and also the exception class(java code) if possible.I found this while searching for info on excepti

Re: How to do exception handling in Activiti v6.0.0

hari — Tue, 24 Apr 2018 06:11:48 GMT

Hi,

The way in which I do is, I define a condition on the outgoing transitions. One will have something like ${Path=="Success"} and other will have something like ${Path=="HandleException"}.

My service task will have code something as below.

try {
System.out.println("In Service Task");

// Do something
execution.setVariable("Path","Success")
} catch (Exception e) {
execution.setVariable("Path","HandleException")
}

Re: How to do exception handling in Activiti v6.0.0

salaboy — Tue, 24 Apr 2018 07:57:08 GMT

I would also suggest to really think about if you want to handle an exception in the process model or if it is a technical matter. If it is a technical matter and not an exceptional business path you should deal with it in Java behind the scenes.

Re: How to do exception handling in Activiti v6.0.0

nami — Tue, 24 Apr 2018 12:04:47 GMT

can u tell me are you using exclusive gateways to manage your conditions in the bpmn xml file ?

Re: How to do exception handling in Activiti v6.0.0

nami — Tue, 24 Apr 2018 12:05:55 GMT

i want to handle some business exceptions as well.

Re: How to do exception handling in Activiti v6.0.0

salaboy — Tue, 24 Apr 2018 12:29:27 GMT

Business Exceptions are fine.. just make sure that those are not Java Exceptions.

Re: How to do exception handling in Activiti v6.0.0

nami — Tue, 24 Apr 2018 12:44:32 GMT

but i need more clarity on how to do this in activiti 6.0.0. Can you please provide more details on this ?

Re: How to do exception handling in Activiti v6.0.0

nami — Wed, 25 Apr 2018 04:02:05 GMT

I am using this as exclusive gateway in my bpmn xml file.

<exclusiveGateway id="exceptionOccured" name="exceptionOccured"/>
<sequenceFlow id="exception" sourceRef="exceptionOccured"
targetRef="catchException">
<conditionExpression xsi:type="tFormalExpression"><![CDATA[${Path == "HandleException"}]]>
</conditionExpression>
</sequenceFlow>
<sequenceFlow id="no-exception" sourceRef="exceptionOccured"
targetRef="endevent1">
<conditionExpression xsi:type="tFormalExpression">${Path != "HandleException"}
</conditionExpression>
</sequenceFlow>

But it throws below exception :

org.activiti.engine.ActivitiException: Unknown property used in expression: ${Path == "HandleException"}
at org.activiti.engine.impl.el.JuelExpression.getValue(JuelExpression.java:52) ~[activiti-engine-6.0.0.jar:6.0.0]

I am setting the Path Variable in the catch block of my java task code

try{

//do something

}

catch (Exception e) {
      logger.error("rest call failed " + e.getMessage() +e.getMessage());
      new ThrowsExceptionBehavior() {
            private static final long serialVersionUID = 1L;
            @Override
            public void execute(DelegateExecution execution) {
            execution.setVariable("Path", "HandleException");
            }
      };
}

Re: How to do exception handling in Activiti v6.0.0

hari — Wed, 25 Apr 2018 04:51:21 GMT

Hi,

You should atleast keep the variable available in your process by the time it reaches your exclusive gateway. The problem above is that you are setting the variable Path a value only when the you come across an exception. This means that when there is no exception, variable Path is unknown. That was the reason for your exception.

If you look at how I did this, irrespective of whether I see an exception or not, I am setting the value for variable Path.

try {
System.out.println("In Service Task");

// Do something
execution.setVariable("Path","Success")
} catch (Exception e) {
execution.setVariable("Path","HandleException")
}