java基础

工作流框架引擎之消息事件流详解

2021-04-18  本文已影响0人  攻城狮Chova

自定义扩展

事件

事件定义

定时器事件定义

<timerEventDefinition>
    <timeDate>2011-03-11T12:13:14</timeDate>
</timerEventDefinition>

<timerEventDefinition>
    <!--等待10天-->
    <timeDuration>P10D</timeDuration>
</timerEventDefinition>

<timerEventDefinition>
    <!--重复3次，每次间隔10小时-->
    <timeCycle>R3/PT10H</timeCycle>
</timerEventDefinition>

0 0/5 * * * ?

  <boundaryEvent id="escalationTimer" cancelActivity="true" attachedToRef="firstLineSupport">
     <timerEventDefinition>
        <timeDuration>${duration}</timeDuration>
     </timerEventDefinition>
  </boundaryEvent>

只有启用job执行器之后,定时器才会被触发.activiti.cfg.xml中的jobExecutorActivate需要设置为true, 默认job执行器是关闭的

错误事件定义

<endEvent id="myErrorEndEvent">
    <!--引用一个错误声明-->
  <errorEventDefinition errorRef="myError" />
</endEvent>

信号事件定义

<!--流程实例,其中会抛出一个信号,并被中间事件捕获-->
<definitions... >
        <!-- declaration of the signal -->
        <signal id="alertSignal" name="alert" />

        <process id="catchSignal">
                <intermediateThrowEvent id="throwSignalEvent" name="Alert">
                        <!-- signal event definition -->
                        <signalEventDefinition signalRef="alertSignal" />
                </intermediateThrowEvent>
                ...
                <intermediateCatchEvent id="catchSignalEvent" name="On Alert">
                        <!-- signal event definition -->
                        <signalEventDefinition signalRef="alertSignal" />
                </intermediateCatchEvent>
                ...
        </process>
</definitions>
触发信号事件
RuntimeService.signalEventReceived(String signalName);
RuntimeService.signalEventReceived(String signalName, String executionId);
捕获信号事件
查询信号事件的订阅
 List<Execution> executions = runtimeService.createExecutionQuery()
      .signalEventSubscriptionName("alert")
      .list();
信号事件范围
<signal id="alertSignal" name="alert" activiti:scope"processInstance"/>

默认情况下,scope的属性为global

信号事件实例

消息事件定义

<!--使用两个消息事件的流程例子,开始事件和中间捕获事件分别声明和引用了两个消息事件-->
<definitions id="definitions"
  xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
  xmlns:activiti="http://activiti.org/bpmn"
  targetNamespace="Examples"
  xmlns:tns="Examples">

  <message id="newInvoice" name="newInvoiceMessage" />
  <message id="payment" name="paymentMessage" />

  <process id="invoiceProcess">

    <startEvent id="messageStart" >
        <messageEventDefinition messageRef="newInvoice" />
    </startEvent>
    ...
    <intermediateCatchEvent id="paymentEvt" >
        <messageEventDefinition messageRef="payment" />
    </intermediateCatchEvent>
    ...
  </process>

</definitions>
触发消息事件
ProcessInstance startProcessInstanceByMessage(String messageName);
ProcessInstance startProcessInstanceByMessage(String messageName, Map<String, Object> processVariables);
ProcessInstance startProcessInstanceByMessage(String messageName, String businessKey, Map<String, Object> processVariables);

这些方法允许使用对应的消息系统流程实例

void messageEventReceived(String messageName, String executionId);
void messageEventReceived(String messageName, String executionId, HashMap<String, Object> processVariables);
查询消息事件订阅
ProcessDefinition processDefinition = repositoryService.createProcessDefinitionQuery()
      .messageEventSubscription("newCallCenterBooking")
      .singleResult();

因为同时只能有一个流程定义关联到消息的订阅点,查询总是返回0或一个结果.如果流程定义更新了,那么只有最新版本的流程定义会订阅到消息事件上

Execution execution = runtimeService.createExecutionQuery()
      .messageEventSubscriptionName("paymentReceived")
      .variableValueEquals("orderId", message.getOrderId())
      .singleResult();

这个查询可以调用对应的查询,通常是流程相关的信息 :最多只能有一个流程实例对应着orderId

消息事件实例
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