今天使用JDBC来操作Hive时，首先启动了hive远程服务模式：hiveserver2 &(表示后台运行)，然后到eclipse中运行程序时出现错误：

java.sql.SQLException: Could not open client transport with JDBC Uri: jdbc:hive2://192.168.182.11:10000/default: Failed to open new session: java.lang.RuntimeException: org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.security.authorize.AuthorizationException): User: root is not allowed to impersonate anonymous
    at org.apache.hive.jdbc.HiveConnection.<init>(HiveConnection.java:224)
    at org.apache.hive.jdbc.HiveDriver.connect(HiveDriver.java:107)
    at java.sql/java.sql.DriverManager.getConnection(DriverManager.java:678)
    at java.sql/java.sql.DriverManager.getConnection(DriverManager.java:252)
    at demo.jdbc.JDBCUtils.getConnection(JDBCUtils.java:31)
    at demo.jdbc.DemoTest.main(DemoTest.java:16)
Caused by: org.apache.hive.service.cli.HiveSQLException: Failed to open new session: java.lang.RuntimeException: org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.security.authorize.AuthorizationException): User: root is not allowed to impersonate anonymous
    at org.apache.hive.jdbc.Utils.verifySuccess(Utils.java:267)
    at org.apache.hive.jdbc.Utils.verifySuccess(Utils.java:258)
    at org.apache.hive.jdbc.HiveConnection.openSession(HiveConnection.java:683)
    at org.apache.hive.jdbc.HiveConnection.<init>(HiveConnection.java:200)
    ... 5 more
Caused by: org.apache.hive.service.cli.HiveSQLException: Failed to open new session: java.lang.RuntimeException: org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.security.authorize.AuthorizationException): User: root is not allowed to impersonate anonymous
    at org.apache.hive.service.cli.session.SessionManager.createSession(SessionManager.java:419)
    at org.apache.hive.service.cli.session.SessionManager.openSession(SessionManager.java:362)
    at org.apache.hive.service.cli.CLIService.openSessionWithImpersonation(CLIService.java:193)
    at org.apache.hive.service.cli.thrift.ThriftCLIService.getSessionHandle(ThriftCLIService.java:440)
    at org.apache.hive.service.cli.thrift.ThriftCLIService.OpenSession(ThriftCLIService.java:322)
    at org.apache.hive.service.rpc.thrift.TCLIService$Processor$OpenSession.getResult(TCLIService.java:1377)
    at org.apache.hive.service.rpc.thrift.TCLIService$Processor$OpenSession.getResult(TCLIService.java:1362)
    at org.apache.thrift.ProcessFunction.process(ProcessFunction.java:39)
    at org.apache.thrift.TBaseProcessor.process(TBaseProcessor.java:39)
    at org.apache.hive.service.auth.TSetIpAddressProcessor.process(TSetIpAddressProcessor.java:56)
    at org.apache.thrift.server.TThreadPoolServer$WorkerProcess.run(TThreadPoolServer.java:286)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.RuntimeException: java.lang.RuntimeException: org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.security.authorize.AuthorizationException): User: root is not allowed to impersonate anonymous
    at org.apache.hive.service.cli.session.HiveSessionProxy.invoke(HiveSessionProxy.java:89)
    at org.apache.hive.service.cli.session.HiveSessionProxy.access$000(HiveSessionProxy.java:36)
    at org.apache.hive.service.cli.session.HiveSessionProxy$1.run(HiveSessionProxy.java:63)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.security.auth.Subject.doAs(Subject.java:422)
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1698)
    at org.apache.hive.service.cli.session.HiveSessionProxy.invoke(HiveSessionProxy.java:59)
    at com.sun.proxy.$Proxy37.open(Unknown Source)
    at org.apache.hive.service.cli.session.SessionManager.createSession(SessionManager.java:410)
    ... 13 more
Caused by: java.lang.RuntimeException: org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.security.authorize.AuthorizationException): User: root is not allowed to impersonate anonymous
    at org.apache.hadoop.hive.ql.session.SessionState.start(SessionState.java:606)
    at org.apache.hadoop.hive.ql.session.SessionState.start(SessionState.java:544)
    at org.apache.hive.service.cli.session.HiveSessionImpl.open(HiveSessionImpl.java:164)
    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.hive.service.cli.session.HiveSessionProxy.invoke(HiveSessionProxy.java:78)
    ... 21 more
Caused by: java.lang.RuntimeException: org.apache.hadoop.ipc.RemoteException:User: root is not allowed to impersonate anonymous
    at org.apache.hadoop.ipc.Client.call(Client.java:1475)
    at org.apache.hadoop.ipc.Client.call(Client.java:1412)
    at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:229)
    at com.sun.proxy.$Proxy30.getFileInfo(Unknown Source)
    at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.getFileInfo(ClientNamenodeProtocolTranslatorPB.java:771)
    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:191)
    at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:102)
    at com.sun.proxy.$Proxy31.getFileInfo(Unknown Source)
    at org.apache.hadoop.hdfs.DFSClient.getFileInfo(DFSClient.java:2108)
    at org.apache.hadoop.hdfs.DistributedFileSystem$22.doCall(DistributedFileSystem.java:1305)
    at org.apache.hadoop.hdfs.DistributedFileSystem$22.doCall(DistributedFileSystem.java:1301)
    at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81)
    at org.apache.hadoop.hdfs.DistributedFileSystem.getFileStatus(DistributedFileSystem.java:1301)
    at org.apache.hadoop.fs.FileSystem.exists(FileSystem.java:1426)
    at org.apache.hadoop.hive.ql.session.SessionState.createRootHDFSDir(SessionState.java:704)
    at org.apache.hadoop.hive.ql.session.SessionState.createSessionDirs(SessionState.java:650)
    at org.apache.hadoop.hive.ql.session.SessionState.start(SessionState.java:582)
    ... 28 more
java.lang.NullPointerException
    at demo.jdbc.DemoTest.main(DemoTest.java:19)

主要报错内容是：java.lang.RuntimeException: org.apache.hadoop.ipc.RemoteException:User: root is not allowed to impersonate anonymous

解决办法：通过httpfs协议访问rest接口，以root用户包装自己用户的方式操作HDFS

首先需要开启rest接口，在hdfs-site.xml文件中加入：

<property>  
<name>dfs.webhdfs.enabled</name>  
<value>true</value>  
</property>  
<property>   

然后在core-site.xml文件中加入：

<property>
<name>hadoop.proxyuser.root.hosts</name>
<value>*</value>
</property>
<property>
<name>hadoop.proxyuser.root.groups</name>
<value>*</value>
</property>