本地mapReduce项目报错：java.lang.NullPointerException at java.lang.ProcessBuilder.start...

    问题：

java.lang.NullPointerException
at java.lang.ProcessBuilder.start(ProcessBuilder.java:1012)
at org.apache.hadoop.util.Shell.runCommand(Shell.java:482)
at org.apache.hadoop.util.Shell.run(Shell.java:455)
at org.apache.hadoop.util.Shell$ShellCommandExecutor.execute(Shell.java:702)
at org.apache.hadoop.util.Shell.execCommand(Shell.java:791)
at org.apache.hadoop.util.Shell.execCommand(Shell.java:774)
at org.apache.hadoop.fs.RawLocalFileSystem.setPermission(RawLocalFileSystem.java:646)
at org.apache.hadoop.fs.RawLocalFileSystem.mkdirs(RawLocalFileSystem.java:434)
at org.apache.hadoop.fs.FilterFileSystem.mkdirs(FilterFileSystem.java:281)
at org.apache.hadoop.mapreduce.JobSubmissionFiles.getStagingDir(JobSubmissionFiles.java:125)
at org.apache.hadoop.mapreduce.JobSubmitter.submitJobInternal(JobSubmitter.java:348)
at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1285)
at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1282)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:422)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1614)
at org.apache.hadoop.mapreduce.Job.submit(Job.java:1282)
at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:1303)
at com.laoxiao.mr.RunTest.main(RunTest.java:51)

    出现原因：缺少hadoop.dll或winutils.exe
    解决办法：缺少哪个，就在本地的...\hadoop-2.5.1_x64\hadoop-2.5.1\bin\下加上哪个。