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;@Overridepublic 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：