写在前面

对于工作流，我们使用最多的是用户任务节点，用户任务节点就是给用户来生成任务的，需要人来手动的处理，而与之对应的还有服务任务节点，这种类型的节点不需要人手动的参与而是程序来执行，即执行某个类的某个方法，这个类一般是org.activiti.engine.delegate.JavaDelegate的子类。下面我们一起来看下如何使用。

1：测试

1.1：设计流程

• 效果图

其中服务节点执行的类设置如下：

类定义如下：

package com.jh.activiti;

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

public class MyServiceTaskDelegate implements JavaDelegate {
    @Override
    public void execute(DelegateExecution execution) throws Exception {
        System.out.println("服务节点对应的类自动执行了！！！");
    }
}

• xml

<?xml version="1.0" encoding="UTF-8"?>
<definitions xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:activiti="http://activiti.org/bpmn" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:omgdc="http://www.omg.org/spec/DD/20100524/DC" xmlns:omgdi="http://www.omg.org/spec/DD/20100524/DI" typeLanguage="http://www.w3.org/2001/XMLSchema" expressionLanguage="http://www.w3.org/1999/XPath" targetNamespace="http://www.activiti.org/test">
    <process id="csdnServiceTask" name="csdnServiceTask" isExecutable="true">
        <startEvent id="startevent1" name="Start"></startEvent>
        <serviceTask id="servicetask1" name="服务任务节点" activiti:class="com.jh.activiti.MyServiceTaskDelegate"></serviceTask>
        <endEvent id="endevent1" name="End"></endEvent>
        <sequenceFlow id="flow1" sourceRef="startevent1" targetRef="servicetask1"></sequenceFlow>
        <sequenceFlow id="flow2" sourceRef="servicetask1" targetRef="endevent1"></sequenceFlow>
    </process>
    <bpmndi:BPMNDiagram id="BPMNDiagram_csdnServiceTask">
        <bpmndi:BPMNPlane bpmnElement="csdnServiceTask" id="BPMNPlane_csdnServiceTask">
            <bpmndi:BPMNShape bpmnElement="startevent1" id="BPMNShape_startevent1">
                <omgdc:Bounds height="35.0" width="35.0" x="190.0" y="220.0"></omgdc:Bounds>
            </bpmndi:BPMNShape>
            <bpmndi:BPMNShape bpmnElement="servicetask1" id="BPMNShape_servicetask1">
                <omgdc:Bounds height="55.0" width="105.0" x="410.0" y="210.0"></omgdc:Bounds>
            </bpmndi:BPMNShape>
            <bpmndi:BPMNShape bpmnElement="endevent1" id="BPMNShape_endevent1">
                <omgdc:Bounds height="35.0" width="35.0" x="720.0" y="220.0"></omgdc:Bounds>
            </bpmndi:BPMNShape>
            <bpmndi:BPMNEdge bpmnElement="flow1" id="BPMNEdge_flow1">
                <omgdi:waypoint x="225.0" y="237.0"></omgdi:waypoint>
                <omgdi:waypoint x="410.0" y="237.0"></omgdi:waypoint>
            </bpmndi:BPMNEdge>
            <bpmndi:BPMNEdge bpmnElement="flow2" id="BPMNEdge_flow2">
                <omgdi:waypoint x="515.0" y="237.0"></omgdi:waypoint>
                <omgdi:waypoint x="720.0" y="237.0"></omgdi:waypoint>
            </bpmndi:BPMNEdge>
        </bpmndi:BPMNPlane>
    </bpmndi:BPMNDiagram>
</definitions>

1.2：部署流程

@Test
public void deploy() {
    Deployment deployment = repositoryService.createDeployment() // 创建部署
            .addClasspathResource("com/jh/activiti/csdnServiceTask.bpmn20.xml") // 加载流程资源文件
            .name("csdn服务节点测试111") // 流程名称
            .deploy(); // 部署
    System.out.println("流程部署ID:" + deployment.getId());
    System.out.println("流程部署Name:" + deployment.getName());
}

1.3：启动实例

@Test
public void startInstance() {
    runtimeService.startProcessInstanceByKey("csdnServiceTask");
}

因为是自动执行，所以，启动实例后就会执行了,输出如下：