如何用Java中的参数构造TestFSMRef对象？

Question

我是Akka框架的新手,所以仍然试图解决问题.实际上,我正在使用TestFSMRef类编写一些测试来测试我的有限状态机actor,称为​​'UptimeMonitorActor'.以下是代码:

@Test
public void testUptimeMonitorActorInInitializingBothPendingState() {
  String systemSMCId = "systemSMC";
  String systemStateModeTopic = "sysStateMode";
  String dataStorageId = "dataStorage";
  String dataSetId = "1";

  Props props = Props.create(UptimeMonitorActor.class, systemSMCId, systemStateModeTopic, dataStorageId, dataSetId);
  TestFSMRef fsm = new TestFSMRef<UptimeMonitorState, UptimeMonitorContext, UptimeMonitorActor>(system, props, some_supervisor, "FSM", null);
  fsm.start();
  log.info(fsm.stateName().toString());
}

我得到了fsm.stateName().toString()的NullPointerException,因为我不知道我要传递给'ev'是什么,这是构造函数中的最后一个参数.参数的类型是:

private final Predef..less.colon.less<T, FSM<S, D>> ev;

我认为这是某种评价.在这种情况下,我应该创建什么来传递'ev'？

谢谢.