java日期计算器：输入日期，完成星期几的计算，并输出星期值（注意日期输入的合法性））

Question

请给出具体的代码

Answer 1

import java.time.LocalDate;
import java.util.Calendar;
import java.util.Scanner;

public class Test023 {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner sc = new Scanner(System.in);
        System.out.println("输入年份:");
        int year = sc.nextInt();

        System.out.println("输入月份:");
        int month = sc.nextInt();

        System.out.println("输入日期:");
        int date = sc.nextInt();

        Calendar c = Calendar.getInstance();// getInstance()返回当前默认语言环境的默认数值格式
        c.set(year, month - 1, 1);

        int week = c.get(Calendar.DAY_OF_WEEK);
        String days = " ";
        switch (week) {
        case 0:
            days = "六";
            break;
        case 1:
            days = "日";
            break;
        case 2:
            days = "一";
            break;
        case 3:
            days = "二";
            break;
        case 4:
            days = "三";
            break;
        case 5:
            days = "四";
            break;
        case 6:
            days = "五";
            break;

        }
        int max = c.getActualMaximum(Calendar.DATE);
        System.out.println("这个月的1号在星期" + days);
        System.out.println("这个月共有" + max + "天");
        c.set(year, month - 1, date);
        int week1 = c.get(Calendar.DAY_OF_WEEK);
        String days1 = " ";
        switch (week1) {
        case 0:
            days1 = "六";
            break;
        case 1:
            days1 = "日";
            break;
        case 2:
            days1 = "一";
            break;
        case 3:
            days1 = "二";
            break;
        case 4:
            days1 = "三";
            break;
        case 5:
            days1 = "四";
            break;
        case 6:
            days1 = "五";
            break;

        }
        System.out.println(year + "年" + month + "月" + date + "号在星期" + days1);
        System.out.println(year + "年" + month + "月的月历为:");
        System.out.println("日\t一\t二\t三\t四\t五\t六");

        for (int j = 1; j < week; j++) {
            System.out.print(" ");
            System.out.print("\t");
        }
        int tag = week;
        for (int i = 1; i <= max; i++) {
            System.out.print(i);
            System.out.print("\t");

            if (tag % 7 == 0) {
                System.out.println("\n");
            }
            tag++;
        }
        System.out.println();
        //以下运行条件java8
        System.out.println("输入第一个日期的年月日，并用空格分开:");
        LocalDate date1 = LocalDate.of(sc.nextInt(), sc.nextInt(), sc.nextInt());
        System.out.println("输入第二个日期的年月日，并用空格分开:");
        LocalDate date2 = LocalDate.of(sc.nextInt(), sc.nextInt(), sc.nextInt());
        long day = Math.abs(date1.toEpochDay() - date2.toEpochDay());// Math.abs()--->返回int值的绝对值|x|
        //toEpochDay()在Module java.base--->Package java.time.chrono
        System.out.printf("这两个日期相差了%d天\n", day);
    }
}