Java操作HDFS

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IOUtils;
import org.junit.Before;

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.URI;
import org.apache.hadoop.fs.FileSystem;
import org.junit.Test;

/**
 * @ClassName:Java_HDFS
 * @Description:TODO
 * @author:Li Wei Ning
 * @Date:2022/4/16 8:40
 */
public class Java_HDFS {
    /**
     * 定义文件系统,类变量
     */
    FileSystem fs = null;

    /**
     * 预处理,@Test之前
     */
    @Before
    public void init(){
        try {

            fs = FileSystem.get(new URI("hdfs://192.168.47.128:9000"),new Configuration(),"root");

        }catch (Exception e){
            e.printStackTrace();
        }finally {
            System.out.println("成功!!!");
        }
    }

    /**
     * 打印文件系统
     */
    @Test
    public void printFs(){
        System.out.println(fs);
    }

    /**
     * 创建文件
     */
    @Test
    public void mkdir(){
        try {
            boolean ret = fs.mkdirs(new Path("/abc"));
            System.out.println(ret);
        }catch (Exception e){
            e.printStackTrace();
        }
    }
    /**
     * 上传文件
     */
    public void put(){
        try {
            fs.copyFromLocalFile(new Path("D:/1.txt"),new Path("/1.txt"));
        }catch (Exception e){
            e.printStackTrace();
        }
    }
    /**
     * 重命名
     */
    @Test
    public void rename(){
        try {
            if(fs.exists(new Path("/s1.txt"))){
                System.out.println(fs.rename(new Path("s1.txt"),new Path("/s2.txt")));
            }
        }catch (Exception e){
            e.printStackTrace();
        }
    }

    /**
     * 下载
     */
    public void downLoad(){
        try {
            InputStream in = fs.open(new Path("/123.txt"));
            FileOutputStream out = new FileOutputStream(new File("D:/123.txt"));
            IOUtils.copyBytes(in,out,2048,true);
        }catch (Exception e){
            e.printStackTrace();
        }
    }
}
W