Camunda ScriptTask SendTask ReceiveTask操作

文章目录

开始
脚本任务(ScriptTask)
发送任务(SendTask)
接收任务(ReceiveTask)
流程图xml

开始

前面我们已经介绍了Camunda最基本的操作和常见的监听器，如果不熟悉Camunda，可以先看一下，方便搭建环境，亲手测试。

Camunda组件与服务与基本操作

Camunda中强大的监听服务

本篇将简单介绍Camunda的Script Task、Send Task、Receive Task。

熟悉这些Task，可以帮我们更好理解Camunda流程。

脚本任务(ScriptTask)

脚本任务

Format:JavaScript

Type:Inline script

execution.setVariable("pa", "javascript");

如果启动流程发现：Can’t find scripting engine for ‘javascript’: scriptEngine is null

可以加入下面的依赖:

<dependency>
    <groupId>org.graalvm.js</groupId>
    <artifactId>js</artifactId>
    <version>23.0.3</version>
</dependency>
<dependency>
    <groupId>org.graalvm.js</groupId>
    <artifactId>js-scriptengine</artifactId>
    <version>23.0.3</version>
</dependency>

除了JavaScript，还可以使用Python、Groovy、Ruby等，得添加相关的依赖。

尽量不要在脚本中实现复杂的逻辑，调试起来比较麻烦，排查问题也痛苦。

发送任务(SendTask)

发送任务

发送任务Send Task和我们之前介绍的Service Task差不多。

可以配置为Java Class然后实现JavaDelegate类。

在实现类中可以获取相关信息，例如：上一个脚本节点设置的参数。

import org.camunda.bpm.engine.delegate.DelegateExecution;
import org.camunda.bpm.engine.delegate.JavaDelegate;

public class SendTaskJavaDelegate implements JavaDelegate {

    @Override
    public void execute(DelegateExecution delegateExecution) {
        System.out.println(SendTaskJavaDelegate.class.getName() + "--start");

        System.out.println("获取参数:" + delegateExecution.getVariable("pa"));
        System.out.println("getId:" + delegateExecution.getId());
        System.out.println("getProcessInstanceId:" + delegateExecution.getProcessInstanceId());
        System.out.println("getActivityInstanceId:" + delegateExecution.getActivityInstanceId());
        System.out.println("getCurrentActivityId:" + delegateExecution.getCurrentActivityId());
        System.out.println("getCurrentActivityName:" + delegateExecution.getCurrentActivityName());
        System.out.println("getProcessBusinessKey:" + delegateExecution.getProcessBusinessKey());
        System.out.println("getProcessDefinitionId:" + delegateExecution.getProcessDefinitionId());
        System.out.println("getBusinessKey:" + delegateExecution.getBusinessKey());
        System.out.println("getEventName:" + delegateExecution.getEventName());
        System.out.println(SendTaskJavaDelegate.class.getName() + "--end");
    }
}

com.example.workflow.delegate.SendTaskJavaDelegate--start
获取参数:javascript
getId:1fbafcb1-c0ac-11ee-b7bf-00ffe7687986
getProcessInstanceId:1fbafcb1-c0ac-11ee-b7bf-00ffe7687986
getActivityInstanceId:Activity_0xcgnyl:2053ba46-c0ac-11ee-b7bf-00ffe7687986
getCurrentActivityId:Activity_0xcgnyl
getCurrentActivityName:发送任务
getProcessBusinessKey:task0002
getProcessDefinitionId:Process_0btcu4b:2:ca1b15a6-c0aa-11ee-8ced-00ffe7687986
getBusinessKey:task0002
getEventName:null
com.example.workflow.delegate.SendTaskJavaDelegate--end

接收任务(ReceiveTask)

接收任务节点可以用来阻塞节点往下执行，比如等一个外部任务完成。

有例如，一个节点必须依赖另一个节点完成，就可以在节点前添加一个接收任务节点，等其他节点完成之后，通过接收任务节点继续往下走。

接收任务

可以根据activityId来查询任务executionId

@Test
public void queryExecutionId() {
    String activityId = "Activity_1nu3d7a";
    Execution execution = runtimeService.createExecutionQuery()
            .activityId(activityId).singleResult();
    System.out.println(execution);
}

select * from act_hi_actinst where ACT_ID_ ='Activity_1nu3d7a';

然后通过executionId来通知接收消息的节点，不用等了，可以到下一个节点了。

@Test
public void signal() {
    String executionId = "2054cbb7-c0ac-11ee-b7bf-00ffe7687986";
    runtimeService.signal(executionId);
}

除了signal，还可以correlateMessage来通知Receive Task完成：

@Test
public void correlateMessage() {
    String messageName = "Message_0ud6hg1";
    runtimeService.correlateMessage(messageName);
}

消息也可以是中文：

@Test
public void correlate() {
    String messageName = "消息2";
    MessageCorrelationBuilder messageCorrelation =
            runtimeService.createMessageCorrelation(messageName);
    messageCorrelation.correlate();
}

完整的测试用例：

import jakarta.annotation.Resource;
import org.camunda.bpm.engine.RuntimeService;
import org.camunda.bpm.engine.runtime.Execution;
import org.camunda.bpm.engine.runtime.MessageCorrelationBuilder;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;


@SpringBootTest
class ApplicationTest {

    @Resource
    private RuntimeService runtimeService;

    @Test
    public void queryExecutionId() {
        String activityId = "Activity_1nu3d7a";
        Execution execution = runtimeService.createExecutionQuery()
                .activityId(activityId).singleResult();
        System.out.println(execution);
    }

    @Test
    public void signal() {
        String executionId = "2054cbb7-c0ac-11ee-b7bf-00ffe7687986";
        runtimeService.signal(executionId);
    }

    @Test
    public void correlateMessage() {
        String messageName = "Message_0ud6hg1";
        runtimeService.correlateMessage(messageName);
    }

    @Test
    public void correlate() {
        String messageName = "消息2";
        MessageCorrelationBuilder messageCorrelation =
                runtimeService.createMessageCorrelation(messageName);
        messageCorrelation.correlate();
    }
}

记得添加依赖，不要加错了，不然执行不了。

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-test</artifactId>
</dependency>

流程图xml

<?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_18zyppt" targetNamespace="http://bpmn.io/schema/bpmn" exporter="Camunda Modeler" exporterVersion="5.19.0" modeler:executionPlatform="Camunda Platform" modeler:executionPlatformVersion="7.20.0">
  <bpmn:process id="Process_0btcu4b" name="任务测试" isExecutable="true" camunda:historyTimeToLive="180">
    <bpmn:startEvent id="StartEvent_1">
      <bpmn:outgoing>Flow_0x6f2m3</bpmn:outgoing>
    </bpmn:startEvent>
    <bpmn:sequenceFlow id="Flow_0x6f2m3" sourceRef="StartEvent_1" targetRef="Activity_08nl9jt" />
    <bpmn:scriptTask id="Activity_08nl9jt" name="脚本任务" scriptFormat="JavaScript">
      <bpmn:incoming>Flow_0x6f2m3</bpmn:incoming>
      <bpmn:outgoing>Flow_1kkp455</bpmn:outgoing>
      <bpmn:script>execution.setVariable("pa", "javascript");</bpmn:script>
    </bpmn:scriptTask>
    <bpmn:sequenceFlow id="Flow_1kkp455" sourceRef="Activity_08nl9jt" targetRef="Activity_0xcgnyl" />
    <bpmn:sendTask id="Activity_0xcgnyl" name="发送任务" camunda:class="com.example.workflow.delegate.SendTaskJavaDelegate">
      <bpmn:incoming>Flow_1kkp455</bpmn:incoming>
      <bpmn:outgoing>Flow_0gw8gq5</bpmn:outgoing>
    </bpmn:sendTask>
    <bpmn:sequenceFlow id="Flow_0gw8gq5" sourceRef="Activity_0xcgnyl" targetRef="Activity_1nu3d7a" />
    <bpmn:receiveTask id="Activity_1nu3d7a" name="接收任务" messageRef="Message_13j3si4">
      <bpmn:incoming>Flow_0gw8gq5</bpmn:incoming>
      <bpmn:outgoing>Flow_09l62nk</bpmn:outgoing>
    </bpmn:receiveTask>
    <bpmn:sequenceFlow id="Flow_09l62nk" sourceRef="Activity_1nu3d7a" targetRef="Activity_1oedt3n" />
    <bpmn:userTask id="Activity_1oedt3n" name="用户任务">
      <bpmn:incoming>Flow_09l62nk</bpmn:incoming>
      <bpmn:outgoing>Flow_1yorrvs</bpmn:outgoing>
    </bpmn:userTask>
    <bpmn:endEvent id="Event_1o1zu4l">
      <bpmn:incoming>Flow_1yorrvs</bpmn:incoming>
    </bpmn:endEvent>
    <bpmn:sequenceFlow id="Flow_1yorrvs" sourceRef="Activity_1oedt3n" targetRef="Event_1o1zu4l" />
  </bpmn:process>
  <bpmn:message id="Message_3n3k1s8" name="消息1" />
  <bpmn:message id="Message_13j3si4" name="消息2" />
  <bpmn:message id="Message_0ud6hg1" name="Message_0ud6hg1" />
  <bpmndi:BPMNDiagram id="BPMNDiagram_1">
    <bpmndi:BPMNPlane id="BPMNPlane_1" bpmnElement="Process_0btcu4b">
      <bpmndi:BPMNShape id="_BPMNShape_StartEvent_2" bpmnElement="StartEvent_1">
        <dc:Bounds x="149" y="99" width="36" height="36" />
      </bpmndi:BPMNShape>
      <bpmndi:BPMNShape id="Activity_0slvat5_di" bpmnElement="Activity_08nl9jt">
        <dc:Bounds x="220" y="77" width="100" height="80" />
        <bpmndi:BPMNLabel />
      </bpmndi:BPMNShape>
      <bpmndi:BPMNShape id="Activity_1obj6uy_di" bpmnElement="Activity_0xcgnyl">
        <dc:Bounds x="360" y="77" width="100" height="80" />
        <bpmndi:BPMNLabel />
      </bpmndi:BPMNShape>
      <bpmndi:BPMNShape id="Activity_1gz5v9p_di" bpmnElement="Activity_1nu3d7a">
        <dc:Bounds x="250" y="210" width="100" height="80" />
        <bpmndi:BPMNLabel />
      </bpmndi:BPMNShape>
      <bpmndi:BPMNShape id="Activity_0k177dl_di" bpmnElement="Activity_1oedt3n">
        <dc:Bounds x="410" y="210" width="100" height="80" />
        <bpmndi:BPMNLabel />
      </bpmndi:BPMNShape>
      <bpmndi:BPMNShape id="Event_1o1zu4l_di" bpmnElement="Event_1o1zu4l">
        <dc:Bounds x="572" y="232" width="36" height="36" />
      </bpmndi:BPMNShape>
      <bpmndi:BPMNEdge id="Flow_0x6f2m3_di" bpmnElement="Flow_0x6f2m3">
        <di:waypoint x="185" y="117" />
        <di:waypoint x="220" y="117" />
      </bpmndi:BPMNEdge>
      <bpmndi:BPMNEdge id="Flow_1kkp455_di" bpmnElement="Flow_1kkp455">
        <di:waypoint x="320" y="117" />
        <di:waypoint x="360" y="117" />
      </bpmndi:BPMNEdge>
      <bpmndi:BPMNEdge id="Flow_0gw8gq5_di" bpmnElement="Flow_0gw8gq5">
        <di:waypoint x="410" y="157" />
        <di:waypoint x="410" y="184" />
        <di:waypoint x="300" y="184" />
        <di:waypoint x="300" y="210" />
      </bpmndi:BPMNEdge>
      <bpmndi:BPMNEdge id="Flow_09l62nk_di" bpmnElement="Flow_09l62nk">
        <di:waypoint x="350" y="250" />
        <di:waypoint x="410" y="250" />
      </bpmndi:BPMNEdge>
      <bpmndi:BPMNEdge id="Flow_1yorrvs_di" bpmnElement="Flow_1yorrvs">
        <di:waypoint x="510" y="250" />
        <di:waypoint x="572" y="250" />
      </bpmndi:BPMNEdge>
    </bpmndi:BPMNPlane>
  </bpmndi:BPMNDiagram>
</bpmn:definitions>