List＜Date＞排序之选择排序

package com.jt.dto;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

/**
 * User: ldj
 * Date: 2022/3/2
 * Time: 22:48
 * Description: No Description
 */
public class DateListSort {

    public static void main(String[] args) {
        ArrayList<Date> dates = new ArrayList<>();
        dates.add(stringToDate("20230215"));
        dates.add(stringToDate("20220302"));
        dates.add(stringToDate("19951109"));
        dates.add(stringToDate("20501123"));

        System.out.println("排序前：" + dates);
        
        //倒序
        testSort(dates);
        System.out.println("排序后：" + dates);
    }


    //String -> Date
    public static Date stringToDate(String dateStr) {
        Date date = null;
        try {
            SimpleDateFormat ft = new SimpleDateFormat("yyyyMMdd");
            date = ft.parse(dateStr);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return date;
    }


    //当i = 1时，j的最大值是4
    public static void testSort(List<Date> list) {
        for (int i = 0; i < list.size() - 1; i++) {
            for (int j = 1; j < list.size() - i; j++) {
                if (list.get(i).before(list.get(i + j))) {
                    Date empty;
                    empty = list.get(i);
                    list.set(i, list.get(i + j));
                    list.set(i + j, empty);
                }
            }
        }
    }
}