Activiti 流程启动的几种方式

比眉伴天荒 2023-01-07 11:23 715阅读 0赞

**[SpringBoot集成的Activiti6.0代码（绘制工具界面代码 + 审批代码）][SpringBoot_Activiti6.0_ _]**

最近在断断续续的学习activiti工作流引擎，为了增强自己对activiti的理解，特此将学习内容整理在博文上，方便自己回忆。

Activiti 的流程启动总结来说有四种启动方式，分别是根据key启动、根据processDefinitionId启动、根据message启动，通过ProcessInstanceBuilder启动。

**1、processDefinitionKey启动**

根据processDefinitionKey启动也就是根据流程定义文件的key启动，是activiti最常用的启动方式（流程定义文件，key为my-process），代码如下：

processDefinitionKey启动，代码如下：

@Test
    @org.activiti.engine.test.Deployment(resources = "my-process.bpmn20.xml")
    public void testStartProcessInstanceByKey() {
    
        RuntimeService runtimeService = activitiRule.getRuntimeService();
    
        Map<String, Object> map = Maps.newHashMap();
        map.put("name", "zhangxingr");
        map.put("sex", "man");
        map.put("age", "21");
    
        ProcessInstance processInstance = runtimeService.startProcessInstanceByKey("my-process", map);
        logger.info("processInstance = {}", processInstance);
    }

**2、processDefinitionId启动**

@Test
    @org.activiti.engine.test.Deployment(resources = "my-process.bpmn20.xml")
    public void testStartProcessInstanceById() {
    
        RuntimeService runtimeService = activitiRule.getRuntimeService();
    
        Map<String, Object> map = Maps.newHashMap();
        map.put("name", "zhangxingr");
        map.put("sex", "man");
        map.put("age", "21");
    
        ProcessDefinition processDefinition = activitiRule.getRepositoryService()
            .createProcessDefinitionQuery().singleResult();
    
        ProcessInstance processInstance = runtimeService
            .startProcessInstanceById(processDefinition.getId(), map);
        logger.info("processInstance = {}, process'key = {}, process'name = {}",
        processInstance, processInstance.getProcessDefinitionKey(),
        processInstance.getName());
    }

**3、message启动**

根据message启动就要复杂一些，需要改动一下流程定义文件的startEvent，增加messageEventDefinition，流程定义文件如下：

message启动，代码如下：

@Test
    @org.activiti.engine.test.Deployment(resources = "my-process-message.bpmn20.xml")
    public void testMessageStart() {
    
        RuntimeService runtimeService = activitiRule.getRuntimeService();
    
        ProcessInstance processInstance = runtimeService
            .startProcessInstanceByMessage("my-message");
    
        logger.info("processInstance = {}", processInstance);
    }

根据message启动底层源码实现最终其实还是会走到用processDefinitionId来启动来，所以建议直接使用processDefinitionId方式启动，底层代码如下：

public ProcessInstance execute(CommandContext commandContext) {
    
        if (messageName == null) {
          throw new ActivitiIllegalArgumentException("Cannot start process instance by message: message name is null");
        }
    
        MessageEventSubscriptionEntity messageEventSubscription = commandContext.getEventSubscriptionEntityManager().findMessageStartEventSubscriptionByName(messageName, tenantId);
    
        if (messageEventSubscription == null) {
          throw new ActivitiObjectNotFoundException("Cannot start process instance by message: no subscription to message with name '" + messageName + "' found.", MessageEventSubscriptionEntity.class);
        }
    
        String processDefinitionId = messageEventSubscription.getConfiguration();
        if (processDefinitionId == null) {
          throw new ActivitiException("Cannot start process instance by message: subscription to message with name '" + messageName + "' is not a message start event.");
        }
    
        DeploymentManager deploymentCache = commandContext.getProcessEngineConfiguration().getDeploymentManager();
    
        ProcessDefinition processDefinition = deploymentCache.findDeployedProcessDefinitionById(processDefinitionId);
        if (processDefinition == null) {
          throw new ActivitiObjectNotFoundException("No process definition found for id '" + processDefinitionId + "'", ProcessDefinition.class);
        }
    
        ProcessInstanceHelper processInstanceHelper = commandContext.getProcessEngineConfiguration().getProcessInstanceHelper();
        ProcessInstance processInstance = processInstanceHelper.createAndStartProcessInstanceByMessage(processDefinition, messageName, processVariables, transientVariables);
    
        return processInstance;
    }

从上面可以看到，最终还是生成了一个processDefinitionId然后调createAndStartProcessInstanceByMessage来启动，具体可以去跟下源码。

**4、processInstanceBuilder启动**

@Test
    @org.activiti.engine.test.Deployment(resources = "my-process.bpmn20.xml")
    public void testProcessInstanceBuilder() {
    
        RuntimeService runtimeService = activitiRule.getRuntimeService();
    
        Map<String, Object> map = Maps.newHashMap();
        map.put("name", "zhangxingr");
        map.put("sex", "man");
        map.put("age", "21");
    
        ProcessInstanceBuilder builder = runtimeService.createProcessInstanceBuilder();
        ProcessInstance processInstance = builder.processDefinitionKey("my-process")
            .businessKey("businessKey001")
            .name("我的流程实例")
            .start();
    
        logger.info("processInstance = {}", processInstance);
    }

到此Activiti 流程启动的几种方式介绍完成。

[SpringBoot_Activiti6.0_ _]: https://download.csdn.net/download/qq_19734597/16788016