1.搭建windows平台的hadoop运行环境

注意文件路径的空格，配置好环境变量

2.开启IDEA，导入hadoop的common和hdfs的jar包

hadoop导包.png

3.建HelloHDFS类

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.*;
import org.apache.hadoop.io.IOUtils;

import java.io.FileInputStream;
import java.io.InputStream;
import java.net.URL;

public class HelloHDFS {

    public static void main(String[] args) throws Exception {

        URL.setURLStreamHandlerFactory(new FsUrlStreamHandlerFactory());
        URL url = new URL("hdfs://192.168.56.100:9000/input.txt");
        InputStream ins = url.openStream();
        IOUtils.copyBytes(ins, System.out, 4096, false);

        // 加java访问hadoop的权限
//            System.setProperty("HADOOP_USER_NAME", "root");

        Configuration conf = new Configuration();
        conf.set("fs.defaultFS", "hdfs://192.168.56.100:9000");
        FileSystem fileSystem = FileSystem.get(conf);

        boolean success = fileSystem.mkdirs(new Path("/msb"));
        System.out.println(success);

        success = fileSystem.exists(new Path("/hello.txt"));
        System.out.println(success);

        success = fileSystem.delete(new Path("/msb"), true);
        System.out.println(success);

        success = fileSystem.exists(new Path("/msb"));
        System.out.println(success);

//            FSDataOutputStream out = fileSystem.create(new Path("/aliyun.txt"), true);
//            FileInputStream fis = new FileInputStream("C:/Users/Jay/Desktop/aliyun.txt");
//            IOUtils.copyBytes(fis, out, 4096, true);

        FSDataOutputStream out = fileSystem.create(new Path("/test.doc"), true);
        FileInputStream in = new FileInputStream("C:/Users/Jay/Desktop/test.doc");
        byte[] buf = new byte[4096];
        int len = in.read(buf);
        while (len != -1) {
            out.write(buf, 0, len);
            len = in.read(buf);
        }
        in.close();
        out.close();

        FileStatus[] statuses = fileSystem.listStatus(new Path("/"));
        for (FileStatus status : statuses) {
            System.out.println(status.getPath());
            System.out.println(status.getPermission());
            System.out.println(status.getReplication());
        }
    }
}

4.运行结果

hdfs运行结果.png

5.输入http://192.168.56.100:50070查看

hadoop浏览器查看.png

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