我是 Hadoop 新手，正在运行 wordCount2 示例。但是我遇到了以下错误
Exception in thread "main" org.apache.hadoop.fs.ParentNotDirectoryException: /tmp (is not a directory)
at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.checkIsDirectory(FSPermissionChecker.java:570)
at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.checkSimpleTraverse(FSPermissionChecker.java:562)
at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.checkTraverse(FSPermissionChecker.java:537)
at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkTraverse(FSDirectory.java:1702)
at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkTraverse(FSDirectory.java:1720)
at org.apache.hadoop.hdfs.server.namenode.FSDirectory.resolvePath(FSDirectory.java:641)
at org.apache.hadoop.hdfs.server.namenode.FSDirMkdirOp.mkdirs(FSDirMkdirOp.java:51)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.mkdirs(FSNamesystem.java:2990)
at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.mkdirs(NameNodeRpcServer.java:1096)
at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.mkdirs(ClientNamenodeProtocolServerSideTranslatorPB.java:652)
at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:503)
at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:989)
at org.apache.hadoop.ipc.Server$RpcCall.run(Server.java:871)
at org.apache.hadoop.ipc.Server$RpcCall.run(Server.java:817)
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:1893)
at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2606)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.apache.hadoop.ipc.RemoteException.instantiateException(RemoteException.java:121)
at org.apache.hadoop.ipc.RemoteException.unwrapRemoteException(RemoteException.java:88)
at org.apache.hadoop.hdfs.DFSClient.primitiveMkdir(DFSClient.java:2474)
at org.apache.hadoop.hdfs.DFSClient.mkdirs(DFSClient.java:2447)
at org.apache.hadoop.hdfs.DistributedFileSystem$27.doCall(DistributedFileSystem.java:1248)
at org.apache.hadoop.hdfs.DistributedFileSystem$27.doCall(DistributedFileSystem.java:1245)
at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81)
at org.apache.hadoop.hdfs.DistributedFileSystem.mkdirsInternal(DistributedFileSystem.java:1245)
at …