activiti 5.12中新增的动态bpmn模型部署

activiti是不错的工作流,最近发现5.12中可以通过在运行期间动态生成一个BPMN的流程模型,因为一般来说,是通过如activiti designer这样的工具,去画好一个BPMN图的,现在可以通过代码的方法去生成了.acitivti 核心工作组的老外提供了一个完整的DEMO来演示,
详细代码在:https://github.com/frederikheremans/activiti-dynamic-process中,
下面小结下,代码其实很简单,如下:

[code="java"]

 @Test

 public void testDynamicDeploy() throws Exception {



 //创建bpmn模型

   BpmnModel model = new BpmnModel();

   Process process = new Process();

   model.addProcess(process);

   process.setId("my-process");



 //创建bpmn元素

   process.addFlowElement(createStartEvent());

   process.addFlowElement(createUserTask("task1", "First task", "fred"));

   process.addFlowElement(createUserTask("task2", "Second task", "john"));

   process.addFlowElement(createEndEvent());



   process.addFlowElement(createSequenceFlow("start", "task1"));

   process.addFlowElement(createSequenceFlow("task1", "task2"));

   process.addFlowElement(createSequenceFlow("task2", "end"));



   // 2.生成BPMN自动布局

   new BpmnAutoLayout(model).execute();



   // 3. 部署这个BPMN模型

   Deployment deployment = activitiRule.getRepositoryService().createDeployment()

     .addBpmnModel("dynamic-model.bpmn", model).name("Dynamic process deployment")

     .deploy();



   // 4. 启动流程实例

   ProcessInstance processInstance = activitiRule.getRuntimeService()

     .startProcessInstanceByKey("my-process");



   // 5 发起任务

   List tasks = activitiRule.getTaskService().createTaskQuery()

     .processInstanceId(processInstance.getId()).list();



   Assert.assertEquals(1, tasks.size());

   Assert.assertEquals("First task", tasks.get(0).getName());

   Assert.assertEquals("fred", tasks.get(0).getAssignee());



   // 6. 保存bpmn流程图 

   InputStream processDiagram = activitiRule.getRepositoryService()

     .getProcessDiagram(processInstance.getProcessDefinitionId());

   FileUtils.copyInputStreamToFile(processDiagram, new File("target/diagram.png"));



   // 7. 保存为bpmn.xml的xml类型文件

   InputStream processBpmn = activitiRule.getRepositoryService()

     .getResourceAsStream(deployment.getId(), "dynamic-model.bpmn");

   FileUtils.copyInputStreamToFile(processBpmn, 

     new File("target/process.bpmn20.xml"));

 }



 //创建task

 protected UserTask createUserTask(String id, String name, String assignee) {

   UserTask userTask = new UserTask();

   userTask.setName(name);

   userTask.setId(id);

   userTask.setAssignee(assignee);

   return userTask;

 }



 //创建箭头

 protected SequenceFlow createSequenceFlow(String from, String to) {

   SequenceFlow flow = new SequenceFlow();

   flow.setSourceRef(from);

   flow.setTargetRef(to);

   return flow;

 }



 protected StartEvent createStartEvent() {

   StartEvent startEvent = new StartEvent();

   startEvent.setId("start");

   return startEvent;

 }



 protected EndEvent createEndEvent() {

   EndEvent endEvent = new EndEvent();

   endEvent.setId("end");

   return endEvent;

 }



 [/code]

 
   其实上面的注解已经比较清楚了.首先是 BpmnModel model = new BpmnModel();
创建一个BPMN模型;然后Process process = new Process();这里创建一个process,
并把这个process加到bpmn模型中去,当然要设置其id了;
  然后用 process.addFlowElement去不断创建BPMN中的每一个元素;
可以看到包括start,end,task,sequence等元素都可以通过new的方法分别创建;
   并且用new BpmnAutoLayout(model).execute();对BPMN元素进行自动布局;
3,4,5部分则比较好理解了;6和7则都是生成BPMN的实际jpg图和生成实际的XML文件
   最后会生成的BPMN图为:
 [img]http://stacktrace.be/blog/wp-content/uploads/2013/03/diagram.png[/img]