idea本地运行hdfs程序

上一篇文章已经搭建好了hadoop单机模式的服务，现在我们要在本地idea上操作hdfs。

首先创建一个maven工程

1.目录结构

  

2.pom.xml

  junit
  junit
  3.8.1
  test



  org.apache.hadoop
  hadoop-core
  2.6.0-mr1-cdh5.11.0



  org.apache.hadoop
  hadoop-common
  2.7.3



  org.apache.hadoop
  hadoop-hdfs
  2.7.3



  org.apache.hadoop
  hadoop-mapreduce-client-core
  2.7.3

3.HdfsTest类

public class HdfsTest {

    public static void main(String[] args) {
        FileSystem fileSystem = null;
        try {
            fileSystem = FileSystem.get(Tools.configuration);
            fileSystem.mkdirs(new Path("/hadoop"));
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                fileSystem.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

4.Tools工具类

public class Tools {

    public static final Configuration configuration = new Configuration();

    static {
        configuration.set("fs.defaultFS", "hdfs://192.168.178.130:9000");
        System.setProperty("HADOOP_USER_NAME", "root");
    }
}

我们现在开始运行一下main方法

java.net.ConnectException: Call From chenzhongwei/10.144.34.146 to myslave1:9000 failed on connection exception: java.net.ConnectException: Connection refused: no further information; For more details see:  http://wiki.apache.org/hadoop/ConnectionRefused    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)    at java.lang.reflect.Constructor.newInstance(Constructor.java:525)    at org.apache.hadoop.net.NetUtils.wrapWithMessage(NetUtils.java:792)    at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:732)    at org.apache.hadoop.ipc.Client.call(Client.java:1479)    at org.apache.hadoop.ipc.Client.call(Client.java:1412)    at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:229)    at $Proxy16.mkdirs(Unknown Source)    at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.mkdirs(ClientNamenodeProtocolTranslatorPB.java:558)    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)    at java.lang.reflect.Method.invoke(Method.java:601)    at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:191)    at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:102)    at $Proxy17.mkdirs(Unknown Source)    at org.apache.hadoop.hdfs.DFSClient.primitiveMkdir(DFSClient.java:3000)    at org.apache.hadoop.hdfs.DFSClient.mkdirs(DFSClient.java:2970)    at org.apache.hadoop.hdfs.DistributedFileSystem$21.doCall(DistributedFileSystem.java:1047)    at org.apache.hadoop.hdfs.DistributedFileSystem$21.doCall(DistributedFileSystem.java:1043)    at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81)    at org.apache.hadoop.hdfs.DistributedFileSystem.mkdirsInternal(DistributedFileSystem.java:1061)    at org.apache.hadoop.hdfs.DistributedFileSystem.mkdirs(DistributedFileSystem.java:1036)    at org.apache.hadoop.fs.FileSystem.mkdirs(FileSystem.java:1881)    at com.hadoop.hdfs.HdfsTest.main(HdfsTest.java:21)    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)    at java.lang.reflect.Method.invoke(Method.java:601)    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)Caused by: java.net.ConnectException: Connection refused: no further information    at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)    at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:692)    at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206)    at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:531)    at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:495)    at org.apache.hadoop.ipc.Client$Connection.setupConnection(Client.java:614)    at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:712)    at org.apache.hadoop.ipc.Client$Connection.access$2900(Client.java:375)    at org.apache.hadoop.ipc.Client.getConnection(Client.java:1528)    at org.apache.hadoop.ipc.Client.call(Client.java:1451)    ... 25 more

发生了报错。

解决的方式是：

把core-site.xml里的服务器名字改成ip

      

     fs.defaultFS       

     hdfs://ip:9000

重启之后继续执行，又报错了。

org.apache.hadoop.security.AccessControlException: Permission denied: user=chenzhongwei, access=WRITE, inode="/hadoop":root:supergroup:drwxr-xr-x    at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.check(FSPermissionChecker.java:319)    at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.check(FSPermissionChecker.java:292)    at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.checkPermission(FSPermissionChecker.java:213)    at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.checkPermission(FSPermissionChecker.java:190)    at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkPermission(FSDirectory.java:1728)    at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkPermission(FSDirectory.java:1712)    at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkAncestorAccess(FSDirectory.java:1695)    at org.apache.hadoop.hdfs.server.namenode.FSDirMkdirOp.mkdirs(FSDirMkdirOp.java:71)    at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.mkdirs(FSNamesystem.java:3896)    at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.mkdirs(NameNodeRpcServer.java:984)    at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.mkdirs(ClientNamenodeProtocolServerSideTranslatorPB.java:622)    at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)    at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:616)    at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:982)    at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2049)    at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2045)    at java.security.AccessController.doPrivileged(Native Method)    at javax.security.auth.Subject.doAs(Subject.java:415)    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1698)    at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2043)    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)    at java.lang.reflect.Constructor.newInstance(Constructor.java:525)    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:3002)    at org.apache.hadoop.hdfs.DFSClient.mkdirs(DFSClient.java:2970)    at org.apache.hadoop.hdfs.DistributedFileSystem$21.doCall(DistributedFileSystem.java:1047)    at org.apache.hadoop.hdfs.DistributedFileSystem$21.doCall(DistributedFileSystem.java:1043)    at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81)    at org.apache.hadoop.hdfs.DistributedFileSystem.mkdirsInternal(DistributedFileSystem.java:1061)    at org.apache.hadoop.hdfs.DistributedFileSystem.mkdirs(DistributedFileSystem.java:1036)    at org.apache.hadoop.fs.FileSystem.mkdirs(FileSystem.java:1881)    at com.hadoop.hdfs.HdfsTest.main(HdfsTest.java:21)    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)    at java.lang.reflect.Method.invoke(Method.java:601)    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)Caused by: org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.security.AccessControlException): Permission denied: user=chenzhongwei, access=WRITE, inode="/hadoop":root:supergroup:drwxr-xr-x    at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.check(FSPermissionChecker.java:319)    at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.check(FSPermissionChecker.java:292)    at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.checkPermission(FSPermissionChecker.java:213)    at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.checkPermission(FSPermissionChecker.java:190)    at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkPermission(FSDirectory.java:1728)    at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkPermission(FSDirectory.java:1712)    at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkAncestorAccess(FSDirectory.java:1695)    at org.apache.hadoop.hdfs.server.namenode.FSDirMkdirOp.mkdirs(FSDirMkdirOp.java:71)    at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.mkdirs(FSNamesystem.java:3896)    at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.mkdirs(NameNodeRpcServer.java:984)    at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.mkdirs(ClientNamenodeProtocolServerSideTranslatorPB.java:622)    at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)    at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:616)    at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:982)    at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2049)    at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2045)    at java.security.AccessController.doPrivileged(Native Method)    at javax.security.auth.Subject.doAs(Subject.java:415)    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1698)    at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2043)    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 $Proxy16.mkdirs(Unknown Source)    at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.mkdirs(ClientNamenodeProtocolTranslatorPB.java:558)    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)    at java.lang.reflect.Method.invoke(Method.java:601)    at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:191)    at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:102)    at $Proxy17.mkdirs(Unknown Source)    at org.apache.hadoop.hdfs.DFSClient.primitiveMkdir(DFSClient.java:3000)    ... 13 more解决方式有两个：

1.在hdfs.site.xml里添加

     

    dfs.permissions      

    false 

2.从代码入手

生成filesystem的时候调用了get方法

fileSystem = FileSystem.get(Tools.configuration);

一直跟着代码进行debug，终于找到了获取用户的最终方法。

UserGroupInformation这个类就是获取当前用户的。

代码如下：

@Public
@Evolving
public static synchronized void loginUserFromSubject(Subject subject) throws IOException {
    ensureInitialized();

    try {
        if(subject == null) {
            subject = new Subject();
        }

        LoginContext le = newLoginContext(authenticationMethod.getLoginAppName(), subject, new UserGroupInformation.HadoopConfiguration(null));
        le.login();
        UserGroupInformation realUser = new UserGroupInformation(subject);
        realUser.setLogin(le);
        realUser.setAuthenticationMethod(authenticationMethod);
        realUser = new UserGroupInformation(le.getSubject());
        String proxyUser = System.getenv("HADOOP_PROXY_USER");
        if(proxyUser == null) {
            proxyUser = System.getProperty("HADOOP_PROXY_USER");
        }

        loginUser = proxyUser == null?realUser:createProxyUser(proxyUser, realUser);
        String fileLocation = System.getenv("HADOOP_TOKEN_FILE_LOCATION");
        if(fileLocation != null) {
            Credentials cred = Credentials.readTokenStorageFile(new File(fileLocation), conf);
            loginUser.addCredentials(cred);
        }

        loginUser.spawnAutoRenewalThreadForUserCreds();
    } catch (LoginException var6) {
        LOG.debug("failure to login", var6);
        throw new IOException("failure to login", var6);
    }

    if(LOG.isDebugEnabled()) {
        LOG.debug("UGI loginUser:" + loginUser);
    }

}

通过以上代码，我们可以简单的在Tools类里的静态块里加上以下代码：

System.setProperty("HADOOP_USER_NAME","root");

以上两种方式都可以解决掉权限问题。

这回再执行一次，成功了。