我是Hadoop新手，正在运行wordCount2示例。但是我遇到了以下错误Exceptioninthread"main"org.apache.hadoop.fs.ParentNotDirectoryException:/tmp(isnotadirectory)atorg.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.checkIsDirectory(FSPermissionChecker.java:570)atorg.apache.hadoop.hdfs.server.namenode.FSPermissionCheck