工作流activiti 6 学习笔记十 服务任务

服务任务调用java程序有三类方法：activiti:class , activiti:delegateExpression,activiti:expression

第一种实现：activiti:class

需要指定的类需要实现 JavaDelegate 或者ActivityBehavior，这个属性已经使用过很多次了，这种方法的一个弊端就是类固化到了代码里面，不够灵活。

bpmn 文件

<process id="myProcess" name="My process" isExecutable="true">
    <startEvent id="startevent1" name="Start"></startEvent>
    <endEvent id="endevent1" name="End"></endEvent>
    <userTask id="usertask1" name="User Task"></userTask>
    <serviceTask id="servicetask1" name="Service Task" activiti:class="org.scf.act.api.task.serviceTask.ActivitiClassDelegate"></serviceTask>
    <sequenceFlow id="flow1" sourceRef="startevent1" targetRef="servicetask1"></sequenceFlow>
    <sequenceFlow id="flow2" sourceRef="servicetask1" targetRef="usertask1"></sequenceFlow>
    <sequenceFlow id="flow3" sourceRef="usertask1" targetRef="endevent1"></sequenceFlow>
  </process>

Delegate 类

package org.scf.act.api.task.serviceTask;

import org.activiti.engine.delegate.DelegateExecution;
import org.activiti.engine.delegate.JavaDelegate;

public class ActivitiClassDelegate implements JavaDelegate{

	@Override
	public void execute(DelegateExecution execution) {
		System.out.println("这是一个service task应用的java类"+execution.getId());
	}

}

测试类：

// 部署流程
		Deployment deploye = rs.createDeployment().addClasspathResource("serviceTask_class.bpmn").deploy();
		
		ProcessDefinition  pdf = rs.createProcessDefinitionQuery().deploymentId(deploye.getId()).singleResult();
		
		
		ProcessInstance  pi = runS.startProcessInstanceById(pdf.getId());
		System.out.println(pi.getId());

运行结果：

这是一个service task应用的java类275006
275005

第二种实现：activiti:delegateExpression

此方法相对动态，能在启动流程时根据业务需要设置不同的业务处理类

bpmn文件

<process id="myProcess" name="My process" isExecutable="true">
    <startEvent id="startevent1" name="Start"></startEvent>
    <endEvent id="endevent1" name="End"></endEvent>
    <userTask id="usertask1" name="User Task"></userTask>
    <serviceTask id="servicetask1" name="Service Task" activiti:delegateExpression="${myDelegate}"></serviceTask>
    <sequenceFlow id="flow1" sourceRef="startevent1" targetRef="servicetask1"></sequenceFlow>
    <sequenceFlow id="flow2" sourceRef="servicetask1" targetRef="usertask1"></sequenceFlow>
    <sequenceFlow id="flow3" sourceRef="usertask1" targetRef="endevent1"></sequenceFlow>
  </process>

delegate类

package org.scf.act.api.task.serviceTask;

import java.io.Serializable;

import org.activiti.engine.delegate.DelegateExecution;
import org.activiti.engine.delegate.JavaDelegate;

public class MyDelegate implements JavaDelegate,Serializable {

	@Override
	public void execute(DelegateExecution execution) {
		System.out.println("这是一个service task应用的delegate expression java类"+execution.getId());
		
	}

}

测试类

// 部署流程
		Deployment deploye = rs.createDeployment().addClasspathResource("serviceTask_delegateExpression.bpmn").deploy();
		
		ProcessDefinition  pdf = rs.createProcessDefinitionQuery().deploymentId(deploye.getId()).singleResult();
		Map<String ,Object> map = new HashMap<String,Object>();
		map.put("myDelegate", new MyDelegate());
		
		ProcessInstance  pi = runS.startProcessInstanceById(pdf.getId(),map);
		System.out.println(pi.getId());

运行结果；

这是一个service task应用的delegate expression java类277509
277505

第三类：activiti:expression 

这个配置就非常强大了，可以直接引入java bean，赋值，取值，业务处理都可以实现。不需要实现delegate接口。

bpmn文件

<process id="myProcess" name="My process" isExecutable="true">
    <startEvent id="startevent1" name="Start"></startEvent>
    <endEvent id="endevent1" name="End"></endEvent>
    <userTask id="usertask1" name="User Task"></userTask>
    <serviceTask id="servicetask1" name="Service Task" activiti:expression="${myBean.print(execution)}"></serviceTask>
    <sequenceFlow id="flow1" sourceRef="startevent1" targetRef="servicetask1"></sequenceFlow>
    <sequenceFlow id="flow3" sourceRef="usertask1" targetRef="endevent1"></sequenceFlow>
    <serviceTask id="servicetask2" name="Service Task" activiti:expression="${execution.setVariable('myName',myBean.myName)}"></serviceTask>
    <sequenceFlow id="flow4" sourceRef="servicetask1" targetRef="servicetask2"></sequenceFlow>
    <sequenceFlow id="flow5" sourceRef="servicetask2" targetRef="usertask1"></sequenceFlow>
  </process>

java bean

package org.scf.act.api.task.serviceTask;

import java.io.Serializable;

import org.activiti.engine.runtime.Execution;

public class MyBean implements Serializable {
	private String myName="scf";
	
	public String getMyName() {
		return myName;
	}
	
	public void print(Execution exe) {
		System.out.println("调用print方法，流程id为"+exe.getId());
	}
}

测试代码：

// 部署流程
	Deployment deploye = rs.createDeployment().addClasspathResource("serviceTask_expression.bpmn").deploy();
	
	ProcessDefinition  pdf = rs.createProcessDefinitionQuery().deploymentId(deploye.getId()).singleResult();
	Map<String ,Object> map = new HashMap<String,Object>();
	map.put("myBean", new MyBean());
	
	ProcessInstance  pi = runS.startProcessInstanceById(pdf.getId(),map);
	System.out.println(pi.getId());
	// 打印设置的变量
	System.out.println(runS.getVariable(pi.getId(), "myName"));

运行结果：

调用print方法，流程id为282509
282505
scf

代码解释：

第一个个taskservice 设置的时打印方法，打印执行流的id

第二个taskservice 设置全局变量给myName，设置的值是 javabean 里面的myName 变量。