我使用Hadoop cdh4运行wordcount程序，我收到错误，无法理解问题 它说＆＃34;文件已存在＆＃34; ，我删除了输出目录，并替换它，但仍然出现相同的错误！
请帮忙！
14/12/11 02:25:25 WARN mapred.JobClient: Use GenericOptionsParser for parsing the arguments. Applications should implement Tool for the same.
14/12/11 02:25:26 INFO mapred.JobClient: Cleaning up the staging area hdfs://localhost:8020/var/lib/hadoop-hdfs/cache/mapred/mapred/staging/training/.staging/job_201412110028_0010
14/12/11 02:25:26 ERROR security.UserGroupInformation: PriviledgedActionException as:training (auth:SIMPLE) cause:org.apache.hadoop.mapred.FileAlreadyExistsException: Output directory hdfs://localhost:8020/user/training/wordcountout already exists
Exception in thread "main" org.apache.hadoop.mapred.FileAlreadyExistsException: Output directory hdfs://localhost:8020/user/training/wordcountout already exists
at org.apache.hadoop.mapred.FileOutputFormat.checkOutputSpecs(FileOutputFormat.java:117)
at org.apache.hadoop.mapred.JobClient$2.run(JobClient.java:986)
at org.apache.hadoop.mapred.JobClient$2.run(JobClient.java:945)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1408)
at org.apache.hadoop.mapred.JobClient.submitJobInternal(JobClient.java:945)
at org.apache.hadoop.mapred.JobClient.submitJob(JobClient.java:919)
at org.apache.hadoop.mapred.JobClient.runJob(JobClient.java:1368)
at wordcount1.WordCount.run(WordCount.java:45)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:84)
at wordcount1.WordCount.main(WordCount.java:51)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.hadoop.util.RunJar.main(RunJar.java:208)
由于