Hadoop Api 基本操作

 hadoop环境配置好后，直接可以在window上进行调试。话不多说，直接上源码。

package cn.terry;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.net.URI;

import java.net.URISyntaxException;

import org.apache.hadoop.conf.Configuration;

import org.apache.hadoop.fs.FileSystem;

import org.apache.hadoop.fs.Path;

import org.apache.hadoop.io.IOUtils;

import org.junit.Before;

import org.junit.Test;

public class hdfsdemo {

  FileSystem fs=null;

  

  @Before

  public void init() throws IOException, InterruptedException, URISyntaxException

  {

fs = FileSystem.get(new URI("hdfs://master:9000"), new Configuration(), "root");

  }

  //upload

  @Test

  public void upload() throws IllegalArgumentException, IOException

  {

  InputStream in= new FileInputStream("c:/ab.txt");

  OutputStream out= fs.create(new Path("/ab.txt"));

  IOUtils.copyBytes(in, out, 4096,true);

  }

  

  @Test

  public void makeDirectory() throws IllegalArgumentException, IOException

  {

boolean ret=  fs.mkdirs(new Path("/code/a"));

  System.out.print(ret);

  }

  

  @Test

  public void testDelete() throws IOException

  {

@SuppressWarnings("deprecation")

boolean ret=  fs.delete(new Path("/code/a"),true);

System.out.print(ret);

  }

/**

* @param args

* @throws URISyntaxException 

* @throws IOException 

*/

public static void main(String[] args) throws IOException, URISyntaxException {

// TODO Auto-generated method stub

//download

  FileSystem fs=FileSystem.get(new URI("hdfs://master:9000"),new Configuration());

  InputStream in= fs.open(new Path("/input/a.txt"));

  OutputStream out =new FileOutputStream("c:/ab.txt");

  IOUtils.copyBytes(in, out, 4096,true);

  

  

}

}