HDFS的JAVA的部分API操作代码

package com.kami.wula01;

import org.apache.hadoop.conf.Configuration;
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 java.net.URI;

public class demo {
    //该类的对象封转了客户端或者服务器的配置
    static Configuration conf=new Configuration();

    public  static void  listStatus()  throws Exception  {
        //该类的对象是一个文件系统对象
        FileSystem hdfs=FileSystem.get(new URI("hdfs://192.168.100.201:8020"),conf);
        //获取某一目录下的所有文件
        FileStatus stats[]=hdfs.listStatus(new Path("/"));

        //遍历输出
        for(int i = 0; i < stats.length; ++i)
            System.out.println(stats[i].getPath().toString());
        hdfs.close();
    }

    public  static void  rename()  throws Exception  {
        FileSystem hdfs=FileSystem.get(new URI("hdfs://192.168.100.201:8020"),conf);
        Path frpaht=new Path("/aaa");
        Path topath=new Path("/aaaaaaa");
        boolean isRename=hdfs.rename(frpaht, topath);
        String result=isRename?"修改成功！":"修改失败！";
        System.out.println(result);
    }

    public  static void  GetTime()  throws Exception  {
        FileSystem hdfs=FileSystem.get(new URI("hdfs://192.168.100.201:8020"),conf);
        FileStatus fileStatus=hdfs.getFileStatus(new Path("/yarn-daemons.txt"));
        long modiTime=fileStatus.getModificationTime();
        System.out.println(modiTime);
    }
    public  static void  deletefile()  throws Exception  {
        FileSystem hdfs=FileSystem.get(new URI("hdfs://192.168.100.201:8020"),conf);
        boolean isDeleted=hdfs.delete(new Path("/user/new"),true);
        System.out.println("Delete?"+isDeleted);
    }
    public  static void  mkdir ()  throws Exception  {
        FileSystem hdfs=FileSystem.get(new URI("hdfs://192.168.100.201:8020"),conf);
        boolean bool2=hdfs.mkdirs(new Path("/user/new"));
        if (bool2)
        {
            System.out.println("创建成功！！");
        }
        else
        {
            System.out.println("创建失败！！");
        }
    }
    public  static void  AddFile()  throws Exception  {
        FileSystem hdfs=FileSystem.get(new URI("hdfs://192.168.100.201:8020"),conf);
        byte[] buff="hello hadoop world!\r\n hadoop ".getBytes();
        FSDataOutputStream outputStream=hdfs.create(new Path("/tmp/file.txt"));
        outputStream.write(buff,0,buff.length);
        outputStream.close();
    }
    public  static void  put()  throws Exception  {
        FileSystem hdfs=FileSystem.get(new URI("hdfs://192.168.100.201:8020"),conf);
        Path src =new Path("C:/123.py");
        Path dst =new Path("/");
        hdfs.copyFromLocalFile(src, dst);
    }
    public  static void  check()  throws Exception  {
        FileSystem hdfs=FileSystem.get(new URI("hdfs://192.168.100.201:8020"),conf);
        Path findf=new Path("/abc");
        boolean isExists=hdfs.exists(findf);
        System.out.println("Exist?"+isExists);
    }

    public static void main(String[] args) throws Exception {
        //获取指定路径所有文件
        listStatus();
        //重命名
        rename();
        //获取文件日期
        GetTime();
        //创建文件夹
        mkdir ();
        //删除文件
        deletefile();
        //创建数据
        AddFile();
        //上传数据
        put();
        //检查目录是否存在
        check();
    }

}