Activiti 5.3：子流程（subProcess）

Activiti 5.3提供了子流程的实现，包括两种基于子流程的实现：
一种是内嵌子流程：子流程元素<subProcess>内嵌在主流程元素<process>之内，只能在该流程中使用该子流程，外部是无法访问到的。这种子流程一般作为局部通用逻辑处理，或者因为特定业务需要，使得比较复杂的单个主流程设计清晰直观；
另一种是调用子流程：首先实现一个流程，在另一个流程中可以调用该流程，通常可以定义一些通用的流程作为这种调用子流程，供其他多个流程定义复用。这种子流程使用<callActivity>元素来进行调用，间接地嵌入到主流程中，用起来比较方便。

内嵌子流程
实现的基于内嵌子流程的流程，示例如图所示：

对应的流程定义文件SubProcessTest.MySubprocess.bpmn20.xml，内容如下所示：
[java]
<?xml version="1.0" encoding="UTF-8"?>
<definitions id="definitions"
    xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:activiti="http://activiti.org/bpmn"
    targetNamespace="Examples">
    <process id="MySubprocess" name="My Subprocess">
        <startEvent id="theStart" />
        <sequenceFlow id="flow1" sourceRef="theStart" targetRef="subProcess" />

        <subProcess id="subProcess">
            <startEvent id="subProcessStart" />
            <sequenceFlow id="flow2" sourceRef="subProcessStart" targetRef="subProcessFork" />
            <parallelGateway id="subProcessFork" />
            <sequenceFlow id="flow3" sourceRef="subProcessFork" targetRef="task1" />
            <sequenceFlow id="flow4" sourceRef="subProcessFork" targetRef="task2" />
            <userTask id="task1" name="Check bank" activiti:candidateGroups="engineering">
                <extensionElements>
                    <activiti:taskListener event="complete"
                        class="org.shirdrn.workflow.activiti.subprocess.CheckBankTask" />
                </extensionElements>
            </userTask>
            <sequenceFlow id="flow5" sourceRef="task1" targetRef="subProcessJoin" />
            <userTask id="task2" name="Investigate software" activiti:candidateGroups="engineering" >
                <extensionElements>
                    <activiti:taskListener event="complete"
                        class="org.shirdrn.workflow.activiti.subprocess.CheckMerchantTask" />
                </extensionElements>
            </userTask>
            <sequenceFlow id="flow6" sourceRef="task2" targetRef="subProcessJoin" />
            <parallelGateway id="subProcessJoin" />
            <sequenceFlow id="flow7" sourceRef="subProcessJoin" targetRef="subProcessEnd" />
            <endEvent id="subProcessEnd" />
        </subProcess>

        <sequenceFlow id="flow10" sourceRef="subProcess" targetRef="taskAfterSubProcess" />
        <userTask id="taskAfterSubProcess" name="Collect message" activiti:candidateGroups="engineering" >
            <extensionElements>
                    <activiti:taskListener event="complete"
                        class="org.shirdrn.workflow.activiti.subprocess.CollectMessageTask" />
            </extensionElements>
        </userTask>
        <sequenceFlow id="flow11" sourceRef="taskAfterSubProcess" targetRef="theEnd" />
        <endEvent id="theEnd" />
    </process>

</definitions>
流程定义中，实现了3个TaskListener，对应的代码分别如下所示：
[java]
package org.shirdrn.workflow.activiti.subprocess;

import java.util.HashMap;
import java.util.logging.Logger;

import org.activiti.engine.delegate.DelegateTask;
import org.activiti.engine.impl.pvm.delegate.TaskListener;

public class CheckBankTask implements TaskListener {

    private final Logger log = Logger.getLogger(CheckBankTask.class.getName());

    @SuppressWarnings("unchecked")
    public void notify(DelegateTask delegateTask) {
        log.info("i am CheckBankTask.");
        System.out.println("in : " + delegateTask.getVariables());
        ((HashMap<String, Object>)delegateTask.getVariables().get("in")).put("next", "CheckBankTask");

补充：软件开发 , Java ,