从键盘输入两个日期，格式如：2022-06-18。判断两个日期的先后，并输出它们之间间隔的天数、周数（不足一周按0计算）。java用到split()，parseInt()

import java.util.Scanner;

public class DateComparison {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("请输入第一个日期（格式：yyyy-MM-dd）：");
        String date1Str = scanner.nextLine();
        System.out.print("请输入第二个日期（格式：yyyy-MM-dd）：");
        String date2Str = scanner.nextLine();

        String[] date1Arr = date1Str.split("-");
        String[] date2Arr = date2Str.split("-");
        int year1 = Integer.parseInt(date1Arr[0]);
        int month1 = Integer.parseInt(date1Arr[1]);
        int day1 = Integer.parseInt(date1Arr[2]);
        int year2 = Integer.parseInt(date2Arr[0]);
        int month2 = Integer.parseInt(date2Arr[1]);
        int day2 = Integer.parseInt(date2Arr[2]);

        int days;
        if (year1 < year2 || (year1 == year2 && month1 < month2) || (year1 == year2 && month1 == month2 && day1 < day2)) {
            days = getDaysBetween(year1, month1, day1, year2, month2, day2);
            System.out.println(date1Str + " 在 " + date2Str + " 之前，间隔 " + days + " 天，" + days / 7 + " 周。");
        } else if (year1 > year2 || (year1 == year2 && month1 > month2) || (year1 == year2 && month1 == month2 && day1 > day2)) {
            days = getDaysBetween(year2, month2, day2, year1, month1, day1);
            System.out.println(date1Str + " 在 " + date2Str + " 之后，间隔 " + days + " 天，" + days / 7 + " 周。");
        } else {
            System.out.println(date1Str + " 和 " + date2Str + " 是同一天。");
        }
    }

    private static int getDaysBetween(int year1, int month1, int day1, int year2, int month2, int day2) {
        int days = 0;
        while (year1 < year2 || month1 < month2 || day1 < day2) {
            days++;
            day1++;
            if (day1 > getDaysOfMonth(year1, month1)) {
                day1 = 1;
                month1++;
                if (month1 > 12) {
                    month1 = 1;
                    year1++;
                }
            }
        }
        return days;
    }

    private static int getDaysOfMonth(int year, int month) {
        switch (month) {
            case 2:
                return isLeapYear(year) ? 29 : 28;
            case 4:
            case 6:
            case 9:
            case 11:
                return 30;
            default:
                return 31;
        }
    }

    private static boolean isLeapYear(int year) {
        return year % 4 == 0 && (year % 100 != 0 || year % 400 == 0);
    }
}

注：以上代码中用到了 isLeapYear() 方法判断闰年，getDaysOfMonth() 方法获取某年某月的天数，getDaysBetween() 方法计算两个日期间隔的天数。