MapReduce源码中无法找到TaskAttemptFinished类

org.apache.hadoop.mapreduce.jobhistory.TaskAttemptFinishedEvent.java中有如下语句
private TaskAttemptFinished datum = new TaskAttemptFinished()。。。
但是编译出现错误，说找不到TaskAttemptFished，我找遍代码也找不到这个类啊。。。
莫非这个类是编译的时候动态生成的吗？
有人知道这个类吗吗？

在TaskAttemptFinishedEvent.java文件中，位于mapreduce/jobhistory目录下：
[ol]

/**

* Event to record successful task completion

*

*/

@InterfaceAudience.Private

@InterfaceStability.Unstable

public class TaskAttemptFinishedEvent  implements HistoryEvent {

  private TaskAttemptFinished datum = new TaskAttemptFinished();

  /**

   * Create an event to record successful finishes for setup and cleanup

   * attempts

   * @param id Attempt ID

   * @param taskType Type of task

   * @param taskStatus Status of task

   * @param finishTime Finish time of attempt

   * @param hostname Host where the attempt executed

   * @param state State string

   * @param counters Counters for the attempt

   */

  public TaskAttemptFinishedEvent(TaskAttemptID id,

      TaskType taskType, String taskStatus,

      long finishTime,

      String hostname, String state, Counters counters) {

    datum.taskid = new Utf8(id.getTaskID().toString());

    datum.attemptId = new Utf8(id.toString());

    datum.taskType = new Utf8(taskType.name());

    datum.taskStatus = new Utf8(taskStatus);

    datum.finishTime = finishTime;

    datum.hostname = new Utf8(hostname);

    datum.state = new Utf8(state);

    datum.counters = EventWriter.toAvro(counters);

  }

  TaskAttemptFinishedEvent() {}

  public Object getDatum() { return datum; }

  public void setDatum(Object datum) {

    this.datum = (TaskAttemptFinished)datum;

  }

  /** Get the task ID */

  public TaskID getTaskId() { return TaskID.forName(datum.taskid.toString()); }

  /** Get the task attempt id */

  public TaskAttemptID getAttemptId() {

    return TaskAttemptID.forName(datum.attemptId.toString());

  }

  /** Get the task type */

  public TaskType getTaskType() {

    return TaskType.valueOf(datum.taskType.toString());

  }

  /** Get the task status */

  public String getTaskStatus() { return datum.taskStatus.toString(); }

  /** Get the attempt finish time */

  public long getFinishTime() { return datum.finishTime; }

  /** Get the host where the attempt executed */

  public String getHostname() { return datum.hostname.toString(); }

  /** Get the state string */

  public String getState() { return datum.state.toString(); }

  /** Get the counters for the attempt */

  Counters getCounters() { return EventReader.fromAvro(datum.counters); }

  /** Get the event type */

  public EventType getEventType() {

    // Note that the task type can be setup/map/reduce/cleanup but the

    // attempt-type can only be map/reduce.

    return getTaskId().getTaskType() == TaskType.MAP

           ? EventType.MAP_ATTEMPT_FINISHED

           : EventType.REDUCE_ATTEMPT_FINISHED;

  }

}[/ol]复制代码

TaskAttemptFinishedEvent这个类，我当然找到了啊，我找不到的类是TaskAttemptFinished，
最后在build目录找到了，可见这个类是编译过程中产生的，svn中并没有这个类