新手刚学hadoop,啥也不懂,跟着视频上的老师敲,因为懒,在代码中少加了一个目录,
重点是最后一句,输出路径不能是已经存在的,最后一个目录地址必须是还没有被创建的,解决把以前建的目录删掉或者在代码中加一个还不存在的目录地址

2021-11-06 16:38:56,759 WARN [org.apache.hadoop.metrics2.impl.MetricsConfig] - Cannot locate configuration: tried hadoop-metrics2-jobtracker.properties,hadoop-metrics2.properties
2021-11-06 16:38:56,798 INFO [org.apache.hadoop.metrics2.impl.MetricsSystemImpl] - Scheduled Metric snapshot period at 10 second(s).
2021-11-06 16:38:56,798 INFO [org.apache.hadoop.metrics2.impl.MetricsSystemImpl] - JobTracker metrics system started
Exception in thread "main" org.apache.hadoop.mapred.FileAlreadyExistsException: Output directory file:/D:/output already exists