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

import java.io.*;
import java.text.SimpleDateFormat;
import java.util.Date;

public class HDFStest1 {

    private static final String hdfsDir = "hdfsDir"; // HDFS目录

    public static void main(String[] args) {
        String studentId = "102202113"; // 学号
        String studentName = "xuxuanyu"; // 姓名拼音
        String localFilePath = "/home/xuxuanyu/xuxuanyu.txt";
        String hdfsFilePath = hdfsDir + studentId + "/" + studentName + ".txt";

        try {
            Configuration conf = new Configuration();
            FileSystem fs = FileSystem.get(conf);

            // 在HDFS上创建目录
            if (!fs.exists(new Path(hdfsDir + studentId))) {
                // 目录不存在时才创建目录
                fs.mkdirs(new Path(hdfsDir + studentId));
            } else {
                System.out.println("Directory already exists: " + hdfsDir + studentId);
            }

            // 上传本地文件到HDFS
            fs.copyFromLocalFile(new Path(localFilePath), new Path(hdfsFilePath));

            // 写入文件内容
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
            String content = studentName + "-" + studentId + " added on " + sdf.format(new Date());
            FSDataOutputStream outputStream = fs.create(new Path(hdfsFilePath));
            outputStream.writeBytes(content);
            outputStream.close();

            // 读取文件内容并输出到控制台
            FSDataInputStream inputStream = fs.open(new Path(hdfsFilePath));
            BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
            String line;
            while ((line = reader.readLine()) != null) {
                System.out.println(line);
            }
            reader.close();



            // 删除目录
            fs.delete(new Path(hdfsDir + studentId), true);

            fs.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}