package com.java;

import java.io.BufferedWriter;

import java.io.File;

import java.io.FileWriter;

import java.text.SimpleDateFormat;

import java.util.Calendar;

import java.util.Random;

/**

 * 随机生成从2000到2018每天一个随机四位数，用于MapReduce计算每年最大值测试

 *

 * @author Logan

 * @createDate 2019-03-18

 * @version 1.0.0

 *

 */

public class Demo {

    /**

     * 生成文件存放在D盘1.txt

     */

    private static final String PATH = "D:\\1.txt";

    private static final SimpleDateFormat format = new SimpleDateFormat("yyyyMMdd");

    public static void main(String[] args) {

        File file = new File(PATH);

        try (

                FileWriter writer = new FileWriter(file);

                BufferedWriter bufWriter = new BufferedWriter(writer);

        ) {

            if (!file.exists()) {

                file.createNewFile();

            }

            Calendar start = Calendar.getInstance();

            Calendar end = Calendar.getInstance();

            start.set(2000, 0, 1);

            end.set(2018, 0, 1);

            StringBuffer line = null;

            while (start.before(end)) {

                line = new StringBuffer();

                line.append(format.format(start.getTime()));

                line.append(getRandom()).append("\n");

                bufWriter.write(line.toString());

                start.add(Calendar.DATE, 1);

            }

        } catch (Exception e) {

            e.printStackTrace();

        }

    }

    /**

     * 随机生成一个四位整数

     *

     * @return

     */

    private static int getRandom() {

        Random r = new Random();

        return r.nextInt(9000) + 1000;

    }

}