hadoop - hadoop2.6 伪分布式 - Java API 操作 HDFS

1.环境

   hadoop 2.6 

   hdfs 地址 ： hdfs://localhost:9000

  开发环境 ： eclipse 

 新建Map/Reduce 工程

2.代码示例

package cn.labelnet.demo;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;

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;

public class UrlTest {

  private static final String HDFS_URL="hdfs://localhost:9000";
  
  private static final String DIR_URL="/zhuo";
  
  private static final String FILE_URL="/zhuo/yuan";
  
  private static final String FILE1_URL="/ming";
  
  public static void main(String[] args) throws Exception {
    FileSystem fs = FileSystem.get(new URI(HDFS_URL),new Configuration());
    
//    createDir(fs);
//    upfile(fs);
    
//       downFile(fs);
    
//    deleteFIle(fs);
    
    deleteDir(fs);
  }



  private static void deleteDir(FileSystem fs) throws IOException {
    //删除文件夹
     boolean g = fs.delete(new Path(DIR_URL),true);
     System.out.println(g);
  }



  private static void deleteFIle(FileSystem fs) throws IOException {
    //删除文件
    boolean b = fs.delete(new Path(FILE1_URL), true);
    System.out.println(b);
  }



  private static void downFile(FileSystem fs) throws IOException {
    //下载文件
      FSDataInputStream fis = fs.open(new Path(FILE_URL));
      IOUtils.copyBytes(fis, System.out,1024,true);
  }



  private static void createDir(FileSystem fs) throws IOException {
    //创建文件夹
    fs.mkdirs(new Path(DIR_URL));
  }
  
  

  private static void upfile(FileSystem fs) throws FileNotFoundException, IOException {
    FileInputStream in=new FileInputStream("yuan.txt");
    //上传文件
    FSDataOutputStream fos = fs.create(new Path(FILE_URL),true);
    IOUtils.copyBytes(in, fos, 1024,true);
  }
  
  
  
  
}

3.Demo 免积分下载