工作流activiti 6 学习笔记八 补偿事件

补偿事件分为：补偿边界事件（捕获事件）和补偿中间事件（抛出事件）。

本示例以银行转账流程进行模拟，从工行转账到农行，工行先扣款，农行加款，抛出补偿中间事件，补偿边界事件捕获，进行补偿操作，农行扣款，工行加款。

bpm文件

<process id="myProcess" name="My process" isExecutable="true">
    <startEvent id="startevent1" name="Start"></startEvent>
    <endEvent id="endevent1" name="End"></endEvent>
    <serviceTask id="servicetask1" name="工商银行扣款" activiti:class="org.scf.act.api.event.compensation.IcbcReduceDelegate"></serviceTask>
    <serviceTask id="servicetask2" name="农业银行加款" activiti:class="org.scf.act.api.event.compensation.ABCAddDelegate"></serviceTask>
    <intermediateThrowEvent id="compensationintermediatethrowevent1" name="CompensationThrowingEvent">
      <compensateEventDefinition></compensateEventDefinition>
    </intermediateThrowEvent>
    <boundaryEvent id="boundarycompensation1" name="Compensate" attachedToRef="servicetask1" cancelActivity="true">
      <compensateEventDefinition></compensateEventDefinition>
    </boundaryEvent>
    <boundaryEvent id="boundarycompensation2" name="Compensate" attachedToRef="servicetask2" cancelActivity="true">
      <compensateEventDefinition></compensateEventDefinition>
    </boundaryEvent>
    <serviceTask id="servicetask3" name="工商银行补偿加款" activiti:class="org.scf.act.api.event.compensation.IcbcAddDelegate" isForCompensation="true"></serviceTask>
    <serviceTask id="servicetask4" name="农业银行补偿扣款" activiti:class="org.scf.act.api.event.compensation.ABCReduceDelegate" isForCompensation="true"></serviceTask>
    <sequenceFlow id="flow1" sourceRef="startevent1" targetRef="servicetask1"></sequenceFlow>
    <sequenceFlow id="flow2" sourceRef="servicetask1" targetRef="servicetask2"></sequenceFlow>
    <sequenceFlow id="flow3" sourceRef="servicetask2" targetRef="compensationintermediatethrowevent1"></sequenceFlow>
    <sequenceFlow id="flow4" sourceRef="compensationintermediatethrowevent1" targetRef="endevent1"></sequenceFlow>
    <association id="association1" sourceRef="boundarycompensation2" targetRef="servicetask4"></association>
    <association id="association2" sourceRef="boundarycompensation1" targetRef="servicetask3"></association>
  </process>

java 代码，四个service task 代码

public class IcbcAddDelegate implements JavaDelegate {

	@Override
	public void execute(DelegateExecution execution) {
		System.out.println("工商银行加款");
	}

}

public class IcbcReduceDelegate implements JavaDelegate {

	@Override
	public void execute(DelegateExecution execution) {
		System.out.println("工商银行扣款");
	}

}
public class ABCAddDelegate implements JavaDelegate {

	@Override
	public void execute(DelegateExecution execution) {
		System.out.println("农业银行加款");
	}
	
}
public class ABCReduceDelegate implements JavaDelegate {

	@Override
	public void execute(DelegateExecution execution) {
		System.out.println("农业银行扣款");
	}

}

测试代码

// 部署流程
			Deployment deploye = rs.createDeployment().addClasspathResource("compensation.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

工商银行扣款
农业银行加款
农业银行扣款
工商银行加款
227505

代码解析：

需要注意的点：补偿事件的触发顺序是，后执行节点先触发。农行加款后执行，因此农行补偿扣款先执行。

补偿参数设置，如果在工行扣款处设置本地变量在工行补偿加款时能获得本地变量

补偿次数执行，如果一个节点执行三次，触发补偿后，补偿也会执行三次