Hadoop之HDFS的API操作

        
            org.apache.hadoop
            hadoop-client
            3.1.3
        
        
            junit
            junit
            4.12
        
        
            org.slf4j
            slf4j-log4j12
            1.7.30
        
    

log4j.rootLogger=INFO, stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d %p [%c] - %m%n
log4j.appender.logfile=org.apache.log4j.FileAppender
log4j.appender.logfile.File=target/spring.log
log4j.appender.logfile.layout=org.apache.log4j.PatternLayout
log4j.appender.logfile.layout.ConversionPattern=%d %p [%c] - %m%n

package com.song.hdfs;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.*;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.Arrays;

public class HdfsClient {

    private FileSystem fs;

    @Before
    public void init() throws URISyntaxException, IOException, InterruptedException {
        // hdfs://hadoop102:8020 是nameNode的通信地址
        URI uri = new URI("hdfs://hadoop102:8020");
        //  获取文件系统
        Configuration configuration = new Configuration();
        // 定义具有操作权限的用户
        String user = "song";
        //  获取客户端对象
        fs = FileSystem.get(uri, configuration, user);
    }

    @After
    public void close() throws IOException {
        // 关闭资源
        fs.close();
    }

    //测试创建目录
    @Test
    public void testMkdirs() throws IOException, URISyntaxException, InterruptedException {

        // 业务操作
        fs.mkdirs(new Path("/xiyou/huaguoshan/"));
    }

    //测试上传
    @Test
    public void testPut() throws IOException, URISyntaxException, InterruptedException {

        // 业务操作
        
        fs.copyFromLocalFile(false, true, new Path("D:\test_data\sunwukong.txt"), new Path("/xiyou/huaguoshan"));
    }


    //测试下载
    @Test
    public void testGet() throws IOException, URISyntaxException, InterruptedException {

        // 业务操作
        
        fs.copyToLocalFile(false, new Path("/xiyou/huaguoshan/sunwukong"), new Path("D:\test_data\sunwukong"), false);
    }

    //测试删除
    @Test
    public void testRm() throws IOException, URISyntaxException, InterruptedException {

        // 业务操作
        
        fs.delete(new Path("/xiyou"), true);
    }

    //测试删除
    @Test
    public void testMv() throws IOException, URISyntaxException, InterruptedException {

        // 业务操作
        
        fs.rename(new Path("/jinguo/shuguo.txt"), new Path("/shuguo1.txt"));
    }


    //  获取文件详情
    @Test
    public void testListFiles() throws IOException {
        RemoteIterator listFiles = fs.listFiles(new Path("/"), true);
        while (listFiles.hasNext()) {
            LocatedFileStatus fileStatus = listFiles.next();

            System.out.println("========" + fileStatus.getPath() + "=========");
            System.out.println(fileStatus.getPermission());
            System.out.println(fileStatus.getOwner());
            System.out.println(fileStatus.getGroup());
            System.out.println(fileStatus.getLen());
            System.out.println(fileStatus.getModificationTime());
            System.out.println(fileStatus.getReplication());
            System.out.println(fileStatus.getBlockSize());
            System.out.println(fileStatus.getPath().getName());

            // 获取块信息
            BlockLocation[] blockLocations = fileStatus.getBlockLocations();
            System.out.println(Arrays.toString(blockLocations));
        }
    }
    @Test
    public void testListStatus() throws IOException, InterruptedException, URISyntaxException{

        // 2 判断是文件还是文件夹
        FileStatus[] listStatus = fs.listStatus(new Path("/"));

        for (FileStatus fileStatus : listStatus) {
            // 如果是文件
            if (fileStatus.isFile()) {
                System.out.println("文件:"+fileStatus.getPath().getName());
            }else {
                System.out.println("目录:"+fileStatus.getPath().getName());
            }
        }
    }


}