The HDFS Java API uses the Read upload file

Package Com.ibeifeng.hadoop.senior.hdfs;

Import Java.io.File;

Import Java.io.FileInputStream;

Import java.io.IOException;

Import org.apache.hadoop.conf.Configuration;

Import Org.apache.hadoop.fs.FSDataInputStream;

Import Org.apache.hadoop.fs.FSDataOutputStream;

Import Org.apache.hadoop.fs.FileSystem;

Import Org.apache.hadoop.fs.Path;

Import Org.apache.hadoop.io.IOUtils;

/**

*

* @author Wangw

*

*/

public class Hdfsapp {

/**

*

* @return

* @throws Exception

* Get filesystem

*/

public static FileSystem Getfilesystem () throws Exception {

Core-site.xml

Configuration conf = new configuration ();

Get filesystem

FileSystem FileSystem = filesystem.get (conf);

System.out.println (FileSystem);

return fileSystem;

}

/**

* Read Data

* @param fileName

* @throws Exception

*/

public static void Read (String fileName) throws Exception {

Get filesystem

FileSystem FileSystem = Getfilesystem ();

String fileName = "/user/wangw/mapreduce/wordcount/wc.input";

Read path

Path Readpath = new Path (fileName);

Open File

Fsdatainputstream instream = Filesystem.open (Readpath);

//

try{

Read

Ioutils.copybytes (instream, System.out, 4096, false);

}catch (Exception e) {

E.printstacktrace ();

}finally{

Close Stream

Ioutils.closestream (instream);

}

}

public static void Main (string[] args) throws Exception {

String fileName = "/user/wangw/mapreduce/wordcount/wc.input";

Read (fileName);

Get filesystem

FileSystem FileSystem = Getfilesystem ();

Write path

String putfilename = "/user/wangw/put-wc.input";

Path Writepath = new Path (putfilename);

Output Stream

Fsdataoutputstream OutStream = filesystem.create (Writepath);

File Input Stream

FileInputStream instream = new FileInputStream (New File (

"/opt/modules/hadoop-2.5.0/wc.input"));

Stream Read/write

try{

Read

Ioutils.copybytes (instream, OutStream, 4096, false);

}catch (Exception e) {

E.printstacktrace ();

}finally{

Close Stream

Ioutils.closestream (instream);

Ioutils.closestream (OutStream);

}

}

}

The HDFS Java API uses the Read upload file