Activiti 5.6：子流程（subProcess）

Activiti 5.6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：

<?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：

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");
		((HashMap<String, Object>)delegateTask.getVariables().get("out")).put("reponse", "subprocess:CheckBankTask->CheckMerchantTask");
	}
}

package org.shirdrn.workflow.activiti.subprocess;

import java.util.HashMap;

public class CheckMerchantTask implements TaskListener {

	private final Logger log = Logger.getLogger(CheckMerchantTask.class.getName());
	
	@SuppressWarnings("unchecked")
	public void notify(DelegateTask delegateTask) {
		log.info("i am CheckMerchantTask.");
		System.out.println("in : " + delegateTask.getVariables());
		((HashMap<String, Object>)delegateTask.getVariables().get("in")).put("previous", "CheckMerchantTask");
	}
}

package org.shirdrn.workflow.activiti.subprocess;

import java.util.Map;

public class CollectMessageTask implements TaskListener {

	private final Logger log = Logger.getLogger(CollectMessageTask.class.getName());
	
	@SuppressWarnings("unchecked")
	public void notify(DelegateTask delegateTask) {
		log.info("i am CollectMessageTask.");
		System.out.println("out : " + (Map<String, Object>)delegateTask.getVariables().get("out"));
		System.out.println("all : " + delegateTask.getVariables());
	}
}

测试用例，代码如下所示：

package org.shirdrn.workflow.activiti.subprocess;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.activiti.engine.repository.Deployment;
import org.activiti.engine.runtime.ProcessInstance;
import org.activiti.engine.task.Task;
import org.shirdrn.workflow.activiti.AbstractTest;

public class MySubProcessTest extends AbstractTest {

	@Override
	protected void initialize() throws Exception {
		Deployment deployment = repositoryService
		.createDeployment()
		.addClasspathResource(
				"diagrams/SubProcessTest.MySubprocess.bpmn20.xml")
		.deploy();	
		deploymentId = deployment.getId();
	}

	@Override
	protected void destroy() throws Exception {
		repositoryService.deleteDeployment(deploymentId, true);	
	}
	
	public void testSubProcess() {
		// prepare data packet
		Map<String, Object> variables = new HashMap<String, Object>();
		Map<String, Object> subVariables = new HashMap<String, Object>();
		variables.put("maxTransCount", 1000000);
		variables.put("merchant", new Merchant("ICBC"));
		variables.put("protocol", "UM32");
		variables.put("repository", "10.10.38.99:/home/shirdrn/repository");
		variables.put("in", subVariables);
		variables.put("out", new HashMap<String, Object>());
		
		// start process instance
		ProcessInstance pi = runtimeService.startProcessInstanceByKey("MySubprocess", variables);
		
		// enter subprocess
		List<Task> tasks = taskService.createTaskQuery().processInstanceId(pi.getId()).orderByTaskName().asc().list();
		assertEquals(2, tasks.size());
		
		for(Task task : tasks) {
			taskService.complete(task.getId());
		}
		
		// leave subprocess
		Task collectTask = taskService.createTaskQuery().processInstanceId(pi.getId()).singleResult();
		assertEquals("Collect message", collectTask.getName());
		
		Map<String, Object> taskVariables = new HashMap<String, Object>();
		taskVariables.put("att", "anything you need");
		taskService.setVariable(collectTask.getId(), "oper", "shirdrn");
		taskService.complete(collectTask.getId(), taskVariables);
	}

}

运行结果信息，如下所示：

2011-3-24 17:36:36 org.shirdrn.workflow.activiti.subprocess.CheckBankTask notify
信息: i am CheckBankTask.
in : {protocol=UM32, repository=10.10.38.99:/home/shirdrn/repository, merchant=Merchant[ICBC], maxTransCount=1000000, in={}, out={}}
2011-3-24 17:36:36 org.shirdrn.workflow.activiti.subprocess.CheckMerchantTask notify
信息: i am CheckMerchantTask.
in : {protocol=UM32, repository=10.10.38.99:/home/shirdrn/repository, merchant=Merchant[ICBC], maxTransCount=1000000, in={next=CheckBankTask}, out={reponse=subprocess:CheckBankTask->CheckMerchantTask}}
2011-3-24 17:36:36 org.shirdrn.workflow.activiti.subprocess.CollectMessageTask notify
信息: i am CollectMessageTask.
out : {reponse=subprocess:CheckBankTask->CheckMerchantTask}
all : {protocol=UM32, repository=10.10.38.99:/home/shirdrn/repository, merchant=Merchant[ICBC], oper=shirdrn, att=anything you need, maxTransCount=1000000, in={previous=CheckMerchantTask, next=CheckBankTask}, out={reponse=subprocess:CheckBankTask->CheckMerchantTask}}