日历表制作

public class Calendar_04 {
	public static int getDaysOfMonth(int year, int month){
		switch(month){
		case 4:
		case 6:
		case 9:
		case 11:
			return 30;
		case 2:
			return isLeap(year) ? 29 : 28;
		case 1:
		case 3:
		case 5:
		case 7:
		case 8:
		case 10:
		case 12:
			return 31;
		default:
			return -1;
		}
		
	}
	/**
	 * 计算自1990 年到所求月份1号之前的的天数
	 * @return
	 */
	public static int getTotalDay(int year, int month){
		int sum = 0;
		for (int i = 1990; i < year; i++) {
			for (int j = 1; j <= 12; j++) {
				sum += getDaysOfMonth(i, j);
			}
		}
		for(int i = 1; i < month; i++){
			sum += getDaysOfMonth(year, i);
		}
		return sum;
	}
	
	public static boolean isLeap(int year){
		if(year % 400 == 0 || year % 4 == 0 && year % 100 != 0){
			return true;
		}else {
			return false;
		}
	}
	// 日历输前的空格
	public static int numOfBlank(int year, int month){
		return ((getTotalDay(year, month) % 7) + 1) % 7;
	}
	public static void print(int year, int month){
		int n = numOfBlank(year, month);
		int count = n;
		for (int i = 0; i < n; i++) {
			System.out.print('\t');
		}
		for(int i = 1; i <= getDaysOfMonth(year, month); i++){
			System.out.print(i + "\t");
			count++;
			if(count % 7 == 0){
				System.out.println();
			}
		}
	}
	public static void start(){
		Scanner sc = new Scanner(System.in);
		int year = sc.nextInt();
		int month = sc.nextInt();
		getTotalDay(year, month);
		System.out.println("===================="+year+"年"+month+"月"+"=======================");
		System.out.println("Sun\tMon\tThu\tWed\tTues\tFri\tSat");
		System.out.println("---------------------------------------------------");
		print(year, month);
	}
	
	public static void main(String[] args) {
		start();
	}

}