通过REST API调用执行Flowable工作流程并获取结果

Question

我正在使用REST API调用开始并完成可流动过程。 那么，如何等待并获得最终的“ ServicEtask”结果将其发送回呼叫者呢？

basic-process.bpmn20.xml：

<process id="basicprocess" name="Basic Process" isExecutable="true">

    <startEvent id="startEvent"/>
    <sequenceFlow sourceRef="startEvent" targetRef="getInput"/>

    <userTask id="getInput" name="Get input from user" />
    <sequenceFlow sourceRef="getInput" targetRef="decision"/>

    <exclusiveGateway id="decision"/>
    <sequenceFlow sourceRef="decision" targetRef="firstServiceTask">
      <conditionExpression xsi:type="tFormalExpression">
        <![CDATA[
          ${number>100}
        ]]>
      </conditionExpression>
    </sequenceFlow>
    <sequenceFlow  sourceRef="decision" targetRef="secondServiceTask">
      <conditionExpression xsi:type="tFormalExpression">
        <![CDATA[
          ${number<=100}
        ]]>
      </conditionExpression>
    </sequenceFlow>

    <serviceTask id="firstServiceTask" name="Number is greater than predefined target"
        flowable:class="demo.service.tasks.FirstServiceTask"/>
    <sequenceFlow sourceRef="firstServiceTask" targetRef="greaterEnd"/>

    <serviceTask id="secondServiceTask" name="Number is less than predefined target"
        flowable:class="demo.service.tasks.SecondServiceTask"/>
    <sequenceFlow sourceRef="secondServiceTask" targetRef="lesserEnd"/>

    <endEvent id="greaterEnd"/>

    <endEvent id="lesserEnd"/>

  </process>

REST API呼叫：

@RestController
@SuppressWarnings("rawtypes")
public class DefinitionsController {

    @Autowired
    private RepositoryService mRepositoryService;

    @Autowired
    private RuntimeService mRuntimeService;

    @Autowired
    private TaskService mTaskService;

    @PostMapping("/start-service")
    public String startService(@RequestBody String input) {
        Integer request = Integer.parseInt(input);
        Map<String, Object> variables = new HashMap<String, Object>();
        variables.put("number", request);

        ProcessInstance instance = mRuntimeService.startProcessInstanceByKey("basicprocess", variables);

        Task userTask = mTaskService.createTaskQuery().processInstanceId(instance.getId()).taskDefinitionKey("getInput").singleResult();
        mTaskService.complete(userTask.getId());

        // How can I invoke the result of FirstServiceTask to return as a response value     
        // result = "FirstServiceTask has been executed";
        return "FirstServiceTask has been executed"
    }

}

ServicEtask：

public class FirstServiceTask implements JavaDelegate{

    @Override
    public void execute(DelegateExecution execution) {
        System.err.println("Came in first service task");

        // Need to invoke this result vale from REST API call for passing to caller as result
        String result = "FirstServiceTask has been executed";
    }

}

Answer 1

一旦完成第一个任务，就没有等待阶段。因此，所有序列流和服务任务都在同一事务中执行。
在您的java委托中，您可以通过设置结果

execution.setVariable("varName", result);

，然后在您的休息服务中，一旦您的任务完成，您可以从runtimeService中检索流程变量。