Operation of the HDFs file system

Package com.bank.utils;

Import Java.io.BufferedInputStream;
Import Java.io.BufferedOutputStream;
Import Java.io.File;
Import Java.io.FileInputStream;
Import java.io.FileNotFoundException;
Import Java.io.FileOutputStream;
Import java.io.IOException;
Import Java.net.URI;
Import Java.text.SimpleDateFormat;
Import Java.util.Date;

Import org.apache.hadoop.conf.Configuration;
Import Org.apache.hadoop.fs.FSDataInputStream;
Import Org.apache.hadoop.fs.FSDataOutputStream;
Import Org.apache.hadoop.fs.FileStatus;
Import Org.apache.hadoop.fs.FileSystem;
Import Org.apache.hadoop.fs.Path;
Import Org.apache.hadoop.io.IOUtils;

/**
* HDFS General operation
* @author Mengyao
*
*/
public class Hdfsutils {

Private final static String Dfs_path = "hdfs://ns1";
Private final static String USER = "root";

public static void Main (string[] args) throws Exception {
Configuration conf = new configuration ();
Conf.set ("Fs.defaultfs", Dfs_path);
Conf.set ("Dfs.nameservices", "ns1");
Conf.set ("dfs.ha.namenodes.ns1", "nn1,nn2");
Conf.set ("Dfs.namenode.rpc-address.ns1.nn1", "h1:9000");
Conf.set ("Dfs.namenode.rpc-address.ns1.nn2", "h2:9000");
Conf.set ("Dfs.client.failover.proxy.provider.ns1", " Org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider ");

FileSystem fs = Filesystem.get (New URI ("Hdfs://ns1"), conf, USER);

Create a folder on HDFs
Createdir (FS, "/hkd/hongkong");

Delete the folder or file on HDFs, the folder is True
Deletefileordir (FS, "/HKD");

Upload local file to HDFs, overwrite if file exists
Upload (FS, "D:/data", "/data.dat");

Download files from HDFs to local
Download (FS, "/cny/data/data", "D:/data");

Delete files on HDFs, if present
DeleteFile (FS, "/data.dat");

Read all file and folder information in the specified directory on HDFs
Readdfspath (FS, "/CNY");
}

public static Boolean Createdir (FileSystem FS, String Dfsnewdir) {
Boolean status = FALSE;
try {
if (Fs.exists (new Path (Dfsnewdir))) {
System.err.println ("This dir exist!");
return status;
}
Status = Fs.mkdirs (new Path (Dfsnewdir));
} catch (IllegalArgumentException e) {
E.printstacktrace ();
} catch (IOException e) {
E.printstacktrace ();
} finally {
try {
Fs.close ();
} catch (IOException e) {
E.printstacktrace ();
}
}

return status;
}

public static Boolean Deletefileordir (FileSystem FS, String Dfspath) {
Boolean status = FALSE;
try {
Status = Fs.delete (new Path (Dfspath), true);
} catch (IllegalArgumentException e) {
E.printstacktrace ();
} catch (IOException e) {
E.printstacktrace ();
} finally {
try {
Fs.close ();
} catch (IOException e) {
E.printstacktrace ();
}
}

return status;
}

public static Boolean upload (FileSystem FS, String LocalPath, String dfspath) {
Boolean status = FALSE;
try {
Fsdataoutputstream out = fs.create (new Path (Dfspath), true);
Bufferedinputstream in = new Bufferedinputstream (new FileInputStream (New File (LocalPath));
Ioutils.copybytes (in, out, 4096, true);
} catch (IllegalArgumentException e) {
E.printstacktrace ();
} catch (IOException e) {
E.printstacktrace ();
} finally {
try {
Fs.close ();
} catch (IOException e) {
E.printstacktrace ();
}
}

return status;
}

public static Boolean Download (FileSystem FS, String Dfspath, String localPath) {
Boolean status = FALSE;
try {
Fsdatainputstream in = Fs.open (new Path (Dfspath));
Bufferedoutputstream out = new Bufferedoutputstream (new FileOutputStream (New File (LocalPath)));
Ioutils.copybytes (in, out, 4096, true);
Status = TRUE;
} catch (IllegalArgumentException e) {
E.printstacktrace ();
} catch (IOException e) {
E.printstacktrace ();
} finally {
try {
Fs.close ();
} catch (IOException e) {
E.printstacktrace ();
}
}

return status;
}

public static Boolean DeleteFile (FileSystem FS, String Dfspath) {
Boolean status = FALSE;
try {
if (Fs.exists (new Path (Dfspath))) {
Status = Fs.delete (new Path (Dfspath), true);
}
} catch (IllegalArgumentException e) {
E.printstacktrace ();
} catch (IOException e) {
E.printstacktrace ();
} finally {
try {
Fs.close ();
} catch (IOException e) {
E.printstacktrace ();
}
}

return status;
}


public static void Readdfspath (FileSystem FS, String Dfspath) {
try {
filestatus[] Liststatus = fs.liststatus (new Path (Dfspath));
for (Filestatus fsstat:liststatus) {
String isdir = Fsstat.isdirectory ()? " Folder ":" File ";
Final String Permission = Fsstat.getpermission (). toString ();
Final short replication = Fsstat.getreplication ();
Final Long len = Fsstat.getlen ();
Final String datestr = new SimpleDateFormat ("Yyyy-mm-dd hh:MM:ss"). Format (New Date (Fsstat.getaccesstime ()));
Final String Path = Fsstat.getpath (). toString ();
System.out.println (isdir+ "\ t" +permission+ "\ T" +replication+ "\ T" +len+ "\ T" +datestr+ "\ T" +path);
}
} catch (FileNotFoundException e) {
E.printstacktrace ();
} catch (IllegalArgumentException e) {
E.printstacktrace ();
} catch (IOException e) {
E.printstacktrace ();
}
}
}

Operation of the HDFs file system