Calendar类一个实例(java)

Calendar类具体方法
https://www.runoob.com/java/java-date-time.html

功能是输入年份月份，输出对应月份与星期的对应关系

package tdm;

import java.math.BigInteger;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Scanner;
import java.util.Date;
import java.util.Calendar;
//import java.util.

public class Main{
    public static void main(String[] args) {
        String WEEK[] = {"Sun. ","Mon. ","Tues.","Wed. ","Thur.","Fri. ","Sat. "};
        Calendar c1 = Calendar.getInstance();
        Calendar c2 = Calendar.getInstance();

        Scanner cin = new Scanner(System.in);
        System.out.println("请输入年份 月份");
        int Year,Month,Date;
        Year = cin.nextInt();
        Month = cin.nextInt();
        Month--;//从0开始的，月份要减一
        Date = 1;
        c1.set(Year,Month,Date);
        c2.set(Year,Month,Date);
        c2.add(Calendar.MONTH,1);
        c2.add(Calendar.DATE,-1);
        int First = c1.get(Calendar.DAY_OF_WEEK);
        for(int i = 0;i < 7;i++)
        {
            System.out.print(WEEK[i] + " ");
        }
        System.out.println();
        for(int i = 1;i < First;i++)
        {
            System.out.print("      ");
        }
        int num = c2.get(Calendar.DATE);
        for(int i = 1;i <= num;i++)
        {
            int Date_now = c1.get(Calendar.DATE);
            int Week = c1.get(Calendar.DAY_OF_WEEK);
            System.out.print(Date_now + "    ");
            if(Date_now < 10)System.out.print(" ");
            if(Week == 7)System.out.println();
            c1.add(Calendar.DATE,1);
        }
        System.out.println();
    }
}