Basic BPMN question: Activiti with Spring boot

Question

So Yesterday I started learning Activiti with Spring Boot. There are many tutorials on the internet in which

• Create a function that saves users to DB.
• Create a BPMN file of the task.
• Create a controller to Start, monitor, and End Tasks.

Suppose there is only one task in my workflow i.e. to send email to a user.

So, The problem is, I am not able to understand that Where Do I need to write the code to Send Email

Basically, once I started a task, which code it will execute?

I've searched entire internet but no able to find any solution. I am completely a beginner in this.

Any help will be appreciated.

Answer 1

1. Use below content for your bpmn.xml file as per requirement,
<?xml version="1.0" encoding="UTF-8"?>
<definitions
        xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
        xmlns:activiti="http://activiti.org/bpmn"
        targetNamespace="Examples">

    <process id="oneTaskProcess" name="The Email task">
        <startEvent id="theStart" />
        <sequenceFlow id="flow1" sourceRef="theStart" targetRef="emailTask" />
        <serviceTask id="emailTask"
                     name="Email task service invocation"
                     activiti:class="com.mycompany.SendEmail">
        </serviceTask>
        <sequenceFlow id="flow2" sourceRef="emailTask" targetRef="theEnd" />
        <endEvent id="theEnd" />
    </process>

</definitions>

2.Create a service task using java as below,

package com.mycompany.SendEmail;
public class SendEmail implements ActivityBehavior {
    @Override
    public void execute(ActivityExecution execution) throws Exception {
        PvmTransition transition = null;
        // do your business logic.
        try{
            transition = execution.getActivity().findOutgoingTransition("theEnd");
        }catch (Exception e){
            //do nothing
        }
        execution.take(transition);
    }
}