Java使用Calendar类实现动态日历

package com.softeem.j2016.example;
 
import java.util.Calendar;
import java.util.Date;
import java.util.Scanner;
 
/**
 * 1.打印日历
 * 1.1当月总天数
 * 1.2当月第一天是周几
 * 2.周末用【】包裹
 * 3.当前日期加“*”
 * @author admin
 * 2021/7/23
 */
public class CalendarDemo {
    //获取一个日期实例
    static  Calendar c = Calendar.getInstance();
 
    public static void show(int year,int month){
        //获取当天日期
        Date today = new Date();
        //获取系统时间的年月日
        int y = today.getYear() +1900;
        int m = today.getMonth() +1;
        int d = today.getDate() ;
 
        c.set(Calendar.YEAR,year);
        c.set(Calendar.MONTH,month-1);
        //设置当前日历的日期为本月的第一天(7.1)
        c.set(Calendar.DAY_OF_MONTH,1);
        //获取当前字段所表示日历的可能具备最大值(本月总天数)
        int days = c.getActualMaximum(Calendar.DAY_OF_MONTH);
        //获取当月第一天是周几(7.1前面设置为本月第一天),周日=1;
        int week = c.get(Calendar.DAY_OF_WEEK)-1;
        //如果当天是周日,则设置为7
        week = week == 0?7 :week;
        //打印空格数
        System.out.printf("%d月一共有%d天,1号是周%d\n",month,days,week);
        System.out.printf("==========【%d】年【%d】月==========\n",year,month);
        System.out.println("一\t二\t三\t四\t五\t六\t日");
        System.out.println("================================");
        //计数器
        int count  = 0;
        //（输出空格）如果当天是星期四则说明有三个空格,需要循环三次，则week-1
        for (int i = 0; i < week - 1; i++) {
            System.out.print("\t");
            count++;
        }
        for (int i = 1; i <=days; i++) {
            count++;
            //根据日期的数值判断是否是周末,如果是则用"[]"包裹
            String date = (count % 7 ==6 || count % 7 == 0)?"["+i+"]\t":i+"\t";
            //在当前日期前使用"*"标记
            date = (y == year && m == month && d == i)?"*" + date:date;
            //输出日期
            System.out.print(date);
            //达到七位则换行
            if (count%7==0){
                System.out.println();
            }
        }
    }
 
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入年份");
        int year = sc.nextInt();
        System.out.println("请输入月份");
        int month = sc.nextInt();
        show(year,month);
    }
}