在这篇文章中，第15.）中提到权限相关的异常，如下：

15/01/30 10:08:17 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable15/01/30 10:08:17 ERROR security.UserGroupInformation: PriviledgedActionException as:zhangchao3 cause:java.io.IOException: Failed to set permissions of path: \tmp\hadoop-zhangchao3\mapred\staging\zhangchao3502228304\.staging to 0700Exception in thread "main" java.io.IOException: Failed to set permissions of path: \tmp\hadoop-zhangchao3\mapred\staging\zhangchao3502228304\.staging to 0700    at     at org.apache.hadoop.fs.FileUtil.setPermission(FileUtil.java:662)    at org.apache.hadoop.fs.RawLocalFileSystem.setPermission(RawLocalFileSystem.java:509)    at org.apache.hadoop.fs.RawLocalFileSystem.mkdirs(RawLocalFileSystem.java:344)    at org.apache.hadoop.fs.FilterFileSystem.mkdirs(FilterFileSystem.java:189)    at org.apache.hadoop.mapreduce.JobSubmissionFiles.getStagingDir(JobSubmissionFiles.java:116)    at org.apache.hadoop.mapred.JobClient$2.run(JobClient.java:856)    at org.apache.hadoop.mapred.JobClient$2.run(JobClient.java:850)    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:1121)    at org.apache.hadoop.mapred.JobClient.submitJobInternal(JobClient.java:850)    at org.apache.hadoop.mapreduce.Job.submit(Job.java:500)    at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:530)    at org.apache.hadoop.examples.WordCount.main(WordCount.java:68)

    根据提示信息，可以看到，这个异常是org.apache.hadoop.fs.FileUtil.checkReturnValue(FileUtil.java:689)行抛出来的，把这个位置的源代码贴出来，研究一下：

private static void checkReturnValue(boolean rv, File p,                                        FsPermission permission                                       ) throws IOException {    if (!rv) {      throw new IOException("Failed to set permissions of path: " + p +                             " to " +                             String.format("%04o", permission.toShort()));    }  }

在上面的异常信息中，FileUtil.java:689行是 throw new IOException(“Failed to ….., 我直接将这个函数的if语句去掉，如下：

private static void checkReturnValue(boolean rv, File p, FsPermission permission)    throws IOException  {}

    这样，chekReturnValue成为一个空函数，这样就不会对权限进行检查，在/home/hadoop/hadoop-1.0.3/中执行， ant jar进行编译，编译中可能遇到的问题见： ，编译好了后，生成如下的文件：

    将编译好生成的hadoop-core-1.0.4-SNAPSHOT.jar文件拷贝到windows上，使用Java Decoder可以看到checkReturnValue已经被修改：

将hadoop-core-1.0.4-SNAPSHOT.jar，修改为hadoop-core-1.0.3.jar文件，覆盖eclipse工程中的hadoop-core-1.0.3.jar文件：

       ------》   

重新执行Run on hadoop，就可以成功的运行了。（如何执行Run on hadoop见： 11节）

修改后的jar包下载地址：