尝试使用Java操作Hadoop，代码如下：
/*** 使用Java API操作HDFS文件系统*/public class HDFSAPP {public static void main(String[] args) throws IOException, URISyntaxException {Configuration configuration = new Configuration();FileSystem fileSystem = FileSystem.get(new URI("hdfs://swarm-worker1:9000"),configuration);Path path = new Path("/hdfsapi/test");boolean mkdirs = fileSystem.mkdirs(path);System.out.println(mkdirs);}}
提示报错信息如下：
Exception in thread "main" org.apache.hadoop.security.AccessControlException: Permission denied: user=vincent, access=WRITE, inode="/":iie4bu:supergroup:drwxr-xr-xat org.apache.hadoop.hdfs.server.namenode.DefaultAuthorizationProvider.checkFsPermission(DefaultAuthorizationProvider.java:279)at org.apache.hadoop.hdfs.server.namenode.DefaultAuthorizationProvider.check(DefaultAuthorizationProvider.java:260)at org.apache.hadoop.hdfs.server.namenode.DefaultAuthorizationProvider.check(DefaultAuthorizationProvider.java:240)at org.apache.hadoop.hdfs.server.namenode.DefaultAuthorizationProvider.checkPermission(DefaultAuthorizationProvider.java:162)at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.checkPermission(FSPermissionChecker.java:152)at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkPermission(FSDirectory.java:3885)at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkPermission(FSDirectory.java:3868)at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkAncestorAccess(FSDirectory.java:3850)at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkAncestorAccess(FSNamesystem.java:6820)at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.mkdirsInternal(FSNamesystem.java:4562)at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.mkdirsInt(FSNamesystem.java:4532)at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.mkdirs(FSNamesystem.java:4505)at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.mkdirs(NameNodeRpcServer.java:884)at org.apache.hadoop.hdfs.server.namenode.AuthorizationProviderProxyClientProtocol.mkdirs(AuthorizationProviderProxyClientProtocol.java:328)at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.mkdirs(ClientNamenodeProtocolServerSideTranslatorPB.java:641)at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:617)at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:1073)at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2281)at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2277)at java.security.AccessController.doPrivileged(Native Method)at javax.security.auth.Subject.doAs(Subject.java:422)at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1924)at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2275)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:106)at org.apache.hadoop.ipc.RemoteException.unwrapRemoteException(RemoteException.java:73)at org.apache.hadoop.hdfs.DFSClient.primitiveMkdir(DFSClient.java:3157)at org.apache.hadoop.hdfs.DFSClient.mkdirs(DFSClient.java:3122)at org.apache.hadoop.hdfs.DistributedFileSystem$19.doCall(DistributedFileSystem.java:1005)at org.apache.hadoop.hdfs.DistributedFileSystem$19.doCall(DistributedFileSystem.java:1001)at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81)at org.apache.hadoop.hdfs.DistributedFileSystem.mkdirsInternal(DistributedFileSystem.java:1001)at org.apache.hadoop.hdfs.DistributedFileSystem.mkdirs(DistributedFileSystem.java:993)at org.apache.hadoop.fs.FileSystem.mkdirs(FileSystem.java:1970)at hadoop.hdfs.HDFSAPP.main(HDFSAPP.java:20)Caused by: org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.security.AccessControlException): Permission denied: user=vincent, access=WRITE, inode="/":iie4bu:supergroup:drwxr-xr-xat org.apache.hadoop.hdfs.server.namenode.DefaultAuthorizationProvider.checkFsPermission(DefaultAuthorizationProvider.java:279)at org.apache.hadoop.hdfs.server.namenode.DefaultAuthorizationProvider.check(DefaultAuthorizationProvider.java:260)at org.apache.hadoop.hdfs.server.namenode.DefaultAuthorizationProvider.check(DefaultAuthorizationProvider.java:240)at org.apache.hadoop.hdfs.server.namenode.DefaultAuthorizationProvider.checkPermission(DefaultAuthorizationProvider.java:162)at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.checkPermission(FSPermissionChecker.java:152)at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkPermission(FSDirectory.java:3885)at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkPermission(FSDirectory.java:3868)at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkAncestorAccess(FSDirectory.java:3850)at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkAncestorAccess(FSNamesystem.java:6820)at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.mkdirsInternal(FSNamesystem.java:4562)at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.mkdirsInt(FSNamesystem.java:4532)at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.mkdirs(FSNamesystem.java:4505)at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.mkdirs(NameNodeRpcServer.java:884)at org.apache.hadoop.hdfs.server.namenode.AuthorizationProviderProxyClientProtocol.mkdirs(AuthorizationProviderProxyClientProtocol.java:328)at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.mkdirs(ClientNamenodeProtocolServerSideTranslatorPB.java:641)at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:617)at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:1073)at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2281)at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2277)at java.security.AccessController.doPrivileged(Native Method)at javax.security.auth.Subject.doAs(Subject.java:422)at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1924)at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2275)at org.apache.hadoop.ipc.Client.call(Client.java:1504)at org.apache.hadoop.ipc.Client.call(Client.java:1441)at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:230)at com.sun.proxy.$Proxy10.mkdirs(Unknown Source)at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.mkdirs(ClientNamenodeProtocolTranslatorPB.java:575)at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)at java.lang.reflect.Method.invoke(Method.java:498)at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:258)at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:104)at com.sun.proxy.$Proxy11.mkdirs(Unknown Source)at org.apache.hadoop.hdfs.DFSClient.primitiveMkdir(DFSClient.java:3155)... 8 more
因为我们的hadoop文件系统的权限如下：
用户是iie4bu，用户组是supergroup，而我们当前用户是vincent，因此没有权限执行。
因此需要指定用户：
FileSystem fileSystem = FileSystem.get(new URI("hdfs://swarm-worker1:9000"),configuration, "iie4bu");
这样就可以成功执行了。
