Camunda如何发送邮件及委托代码讲解

💖专栏简介

✔️本专栏将从Camunda(卡蒙达) 7中的关键概念到实现中国式工作流相关功能。

✔️文章中只包含演示核心代码及测试数据，完整代码可查看作者的开源项目snail-camunda

✔️请给snail-camunda 点颗星吧😘

💖什么是委托代码

委托代码是在流程执行过程中发生某些事件时执行外部Java代码、脚本或求值表达式。在Camunda中分为如下4种：

Java Delegate 【Java委托】
Delegate Variable Mapping 【委托变量映射】
Execution Listener 【执行监听器】
Task Listener 【任务监听器】

💖Java Delegate

要实现一个可以在流程执行期间调用的类，该类需要实现org.camunda.bpm.engine.delegate.JavaDelegate 接口，并在execute方法中提供所需的逻辑。当流程执行到达这个特定步骤时，它将执行在该方法中定义的逻辑，并以默认的BPMN 2.0方式离开活动。

接下来通过Send Task发送邮件来演示：

<?xml version="1.0" encoding="UTF-8"?>
<bpmn:definitions xmlns:bpmn="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:dc="http://www.omg.org/spec/DD/20100524/DC" xmlns:camunda="http://camunda.org/schema/1.0/bpmn" xmlns:di="http://www.omg.org/spec/DD/20100524/DI" xmlns:modeler="http://camunda.org/schema/modeler/1.0" id="Definitions_19cqxxj" targetNamespace="http://bpmn.io/schema/bpmn" exporter="Camunda Modeler" exporterVersion="5.19.0" modeler:executionPlatform="Camunda Platform" modeler:executionPlatformVersion="7.15.0">
  <bpmn:process id="Process_0cu2yds" isExecutable="true">
    <bpmn:startEvent id="StartEvent_1">
      <bpmn:outgoing>Flow_0yf2ndo</bpmn:outgoing>
    </bpmn:startEvent>
    <bpmn:sequenceFlow id="Flow_0yf2ndo" sourceRef="StartEvent_1" targetRef="Activity_1jxjk7q" />
    <bpmn:userTask id="Activity_1jxjk7q" name="发起人" camunda:assignee="${initiator}">
      <bpmn:incoming>Flow_0yf2ndo</bpmn:incoming>
      <bpmn:outgoing>Flow_0ti4nj0</bpmn:outgoing>
    </bpmn:userTask>
    <bpmn:sequenceFlow id="Flow_0ti4nj0" sourceRef="Activity_1jxjk7q" targetRef="Activity_0g9hruk" />
    <bpmn:sendTask id="Activity_0g9hruk" name="戴宗报信" camunda:class="com.lonewalker.snail.delegate.SendEmailDelegate">
      <bpmn:incoming>Flow_0ti4nj0</bpmn:incoming>
      <bpmn:outgoing>Flow_0mub7f0</bpmn:outgoing>
    </bpmn:sendTask>
    <bpmn:sequenceFlow id="Flow_0mub7f0" sourceRef="Activity_0g9hruk" targetRef="Activity_111hike" />
    <bpmn:userTask id="Activity_111hike" name="宋江" camunda:assignee="${head}">
      <bpmn:incoming>Flow_0mub7f0</bpmn:incoming>
      <bpmn:outgoing>Flow_1kv7i02</bpmn:outgoing>
    </bpmn:userTask>
    <bpmn:endEvent id="Event_037pynp">
      <bpmn:incoming>Flow_1kv7i02</bpmn:incoming>
    </bpmn:endEvent>
    <bpmn:sequenceFlow id="Flow_1kv7i02" sourceRef="Activity_111hike" targetRef="Event_037pynp" />
  </bpmn:process>
  <bpmndi:BPMNDiagram id="BPMNDiagram_1">
    <bpmndi:BPMNPlane id="BPMNPlane_1" bpmnElement="Process_0cu2yds">
      <bpmndi:BPMNShape id="_BPMNShape_StartEvent_2" bpmnElement="StartEvent_1">
        <dc:Bounds x="179" y="99" width="36" height="36" />
      </bpmndi:BPMNShape>
      <bpmndi:BPMNShape id="Activity_0mqjfh8_di" bpmnElement="Activity_1jxjk7q">
        <dc:Bounds x="270" y="77" width="100" height="80" />
      </bpmndi:BPMNShape>
      <bpmndi:BPMNShape id="Activity_1tg1kpv_di" bpmnElement="Activity_0g9hruk">
        <dc:Bounds x="430" y="77" width="100" height="80" />
      </bpmndi:BPMNShape>
      <bpmndi:BPMNShape id="Activity_1mr4xv3_di" bpmnElement="Activity_111hike">
        <dc:Bounds x="590" y="77" width="100" height="80" />
      </bpmndi:BPMNShape>
      <bpmndi:BPMNShape id="Event_037pynp_di" bpmnElement="Event_037pynp">
        <dc:Bounds x="752" y="99" width="36" height="36" />
      </bpmndi:BPMNShape>
      <bpmndi:BPMNEdge id="Flow_0yf2ndo_di" bpmnElement="Flow_0yf2ndo">
        <di:waypoint x="215" y="117" />
        <di:waypoint x="270" y="117" />
      </bpmndi:BPMNEdge>
      <bpmndi:BPMNEdge id="Flow_0ti4nj0_di" bpmnElement="Flow_0ti4nj0">
        <di:waypoint x="370" y="117" />
        <di:waypoint x="430" y="117" />
      </bpmndi:BPMNEdge>
      <bpmndi:BPMNEdge id="Flow_0mub7f0_di" bpmnElement="Flow_0mub7f0">
        <di:waypoint x="530" y="117" />
        <di:waypoint x="590" y="117" />
      </bpmndi:BPMNEdge>
      <bpmndi:BPMNEdge id="Flow_1kv7i02_di" bpmnElement="Flow_1kv7i02">
        <di:waypoint x="690" y="117" />
        <di:waypoint x="752" y="117" />
      </bpmndi:BPMNEdge>
    </bpmndi:BPMNPlane>
  </bpmndi:BPMNDiagram>
</bpmn:definitions>

还是一样的将类路径替换为自己的。

此外，通过field injection【字段注入】设置目标邮箱，字段注入的Name建议使用驼峰命名，因为我们在代码中需要使用。

关于邮箱的设置可查看此篇【Springboot发送邮件】

在配置文件中新增邮件相关配置

###邮件相关配置
#邮箱服务器地址
spring.mail.host=smtp.163.com
#邮箱用户名
spring.mail.username=xxx@163.com
#邮箱密码（注意：qq邮箱应该使用独立密码，去qq邮箱设置里面获取 163邮箱使用设置的授权码）
#这里把授权码改为自己的
spring.mail.password=QJBFXYUNMQYRCGSU
##编码格式
spring.mail.default-encoding=UTF-8
##端口号   465或者994
spring.mail.port=465
spring.mail.protocol=smtps
##发送邮件地址
spring.mail.from=xxx@163.com

新增发送邮件的委托代码

@RequiredArgsConstructor
@Slf4j
@Component
public class SendEmailDelegate implements JavaDelegate {

    private final JavaMailSender mailSender;

    @Value("${spring.mail.from}")
    private String addresser;

    private Expression sendingTarget;

    @Override
    public void execute(DelegateExecution execution) throws Exception {
        String initiator = (String) execution.getVariable("initiator");
        String processInstanceId = execution.getProcessInstanceId();
        String content = initiator+"--发起的审批流程抄送给您["+processInstanceId+"]";

        //获取收件人，也可以在表单设计时存入数据库
        String recipient = String.valueOf(sendingTarget.getValue(execution));
        //改成自己的邮箱账号调试
        SimpleMailMessage mailMessage = new SimpleMailMessage();
        //设置发件人
        mailMessage.setFrom(addresser);
        //设置收件人
        mailMessage.setTo(recipient);
        //设置主题
        mailMessage.setSubject("审批抄送");
        //设置内容
        mailMessage.setText(content);
        //发送邮件
        mailSender.send(mailMessage);
    }
}

测试结果：