1、在HDFS文件系统中新增目录

新增代码

查看结果

2、删除目录

删除代码

查看结果

3、查看目录

代码

执行结果

代码

package com.lizh.hadoop.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.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IOUtils;
public class HdfsApp {

    public static FileSystem getFileSystem() throws IOException{
        Configuration conf = new Configuration();
        FileSystem fs = FileSystem.get(conf);
        return fs;
    }
    
    /**
     * 利用HDSF的api读取文件内容
     * @param path1
     */
    public static void readFile(String path1) {
        try {
            FileSystem fs = getFileSystem();
            Path path = new Path(path1);
            FSDataInputStream in = fs.open(path);
            IOUtils.copyBytes(in, System.out, 4000, false);
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }
        
    }
    
    /**
     * 利用HDFS的api上传文件
     */
    public static void putFile(){
        //把/opt/modules/hadoop-2.5.0/wc.input 内容写入到 /user/beifeng/put-wc.input
        //write file
        FileInputStream fisin =null;
        FSDataOutputStream fsoutstream =null;
        try {
            String filename="/user/beifeng/put-wc.input";//文件系统目录
            Path inputpath = new Path(filename);   
            FileSystem fs = getFileSystem();//获取文件系统
            fsoutstream = fs.create(inputpath);
        
            fisin = new FileInputStream(new File("/opt/modules/hadoop-2.5.0/wc.input"));//本地系统目录文件
            IOUtils.copyBytes(fisin, fsoutstream, 4000, false);
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }finally{
            IOUtils.closeStream(fsoutstream);
            IOUtils.closeStream(fisin);
        }
    }
    
    /**
     * 利用HDFS的api创建目录
     */
    public static void createDir(String filepath){
        try {
            FileSystem fs = getFileSystem();//获取文件系统
            fs.mkdirs(new Path(filepath));
            fs.close();
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }
        
    }
    /**
     * 删除目录
     * @param filepath
     */
    public static void deleteDir(String filepath){
        try {
            FileSystem fs = getFileSystem();//获取文件系统
            fs.deleteOnExit(new Path(filepath));
            fs.close();
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }
    }
    
    public static void listDir(){
        try {
            FileSystem fs = getFileSystem();//获取文件系统
            FileStatus[] fslarray = fs.listStatus(new Path("/user/beifeng"));
            for(FileStatus files:fslarray){
                System.out.println(files.getPath());
                
            }
            fs.close();
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }finally{
            
        }
    }
    
    public static void main(String[] args) throws Exception{
        listDir();
    }
    
}