import org.apache.hadoop.mapreduce.jobhistory.JobHistoryEventHandler; //导入依赖的package包/类
@Override
protected EventHandler<JobHistoryEvent> createJobHistoryHandler(
    AppContext context) {
  JobHistoryEventHandler eventHandler = new JobHistoryEventHandler(context, 
      getStartCount());
  return eventHandler;
}
 

import org.apache.hadoop.mapreduce.jobhistory.JobHistoryEventHandler; //导入依赖的package包/类
@Override
protected EventHandler<JobHistoryEvent> createJobHistoryHandler(
    AppContext context) {
  return new JobHistoryEventHandler(context, getStartCount()) {
    @Override
    public void serviceStop() throws Exception {
      numStops++;
      JobHistoryEventHandlerStopped = numStops;
      super.serviceStop();
    }
  };
}
 

import org.apache.hadoop.mapreduce.jobhistory.JobHistoryEventHandler; //导入依赖的package包/类
@Override
protected EventHandler<JobHistoryEvent> createJobHistoryHandler(
    AppContext context) {
  spyHistoryService =
      Mockito.spy((JobHistoryEventHandler) super
          .createJobHistoryHandler(context));
  spyHistoryService.setForcejobCompletion(this.isLastAMRetry);
  return spyHistoryService;
}
 

import org.apache.hadoop.mapreduce.jobhistory.JobHistoryEventHandler; //导入依赖的package包/类
@Override
protected EventHandler<JobHistoryEvent> createJobHistoryHandler(
    AppContext context) {
  return new JobHistoryEventHandler(context, getStartCount()) {
    @Override
    protected void serviceStart() {
      // Don't start any event draining thread.
      super.eventHandlingThread = new Thread();
      super.eventHandlingThread.start();
    }
  };
}