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