Javaを使用して永久カレンダーを作成する

package com.softeem.test01;
import java.time.Month;
import java.time.Year;
import java.util.Scanner;
public class DynamicCalendar {
	private int y;
	private int m;
	public DynamicCalendar(int y, int m) {
		this.y = y;
		this.m = m;
	}
	public boolean year(int ye) {
		return ye % 4 == 0 && ye % 100 != 0 || ye % 400 == 0;
	}
	public int month(int ye, int mon) {
		if (mon < 1 || mon > 12) {
			System.out.println("输入错误");
			return 0;
		}
		switch (mon) {
		case 4:
		case 6:
		case 9:
		case 11:
			return 30;
		case 2:
			return year(ye) ? 29 : 28;
		default:
			return 31;
		}
	}
	public int method() {
		int count = 0;
		for (int i = 1900; i < this.y; i++) {
			count += year(i) ? 366 : 365;
		}
 		for (int i = 1; i < m; i++) {
			count += month(this.y, i);
		}
		return count;
	}

	public void printCalendar() {
		int space = method() % 7;
		int count = month(y, m);
		System.out.println("==============万年历【" + y + "】年【" + m + "】月===================");
		System.out.println("一\t二\t三\t四\t五\t六\t日");
		System.out.println("==================================================");
		int sum = 0;
		for (int i = 0; i < space; i++) {
			System.out.print("\t");
			sum++;
		}
		for (int i = 1; i < count; i++) {
			sum++;
			System.out.print(i + "\t");
			if (sum == 7) {
				System.out.println();
				sum = 0;
			}
		}
	}
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		System.out.print("请输入年份：");
		int y = sc.nextInt();
		System.out.print("请输入月份：");
		int m = sc.nextInt();
		DynamicCalendar dc = new DynamicCalendar(y, m);
		dc.printCalendar();
	}
}