万年历的编写和打印

package MyDay05;
import java.util.Scanner;
public class 万年历2 {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);

        //1900.1.1 为星期1
        System.out.print("输入年：");
        int year=scan.nextInt();
        System.out.print("输入月:");
        int month=scan.nextInt();
        int sumDay01=0;
        int sumDay02=0;
        int a=0;


        for (int i = 1900; i < year; i++) {
            if(i%4==0&&i%100!=0||i%400==0){
                sumDay01+=366;
            }else {
                sumDay01+=365;
            }
        }
        for (int i = 1; i < month; i++) {
            switch (i){
                case 1:case 3:case 5:case 7:case 8:case 10:case 12:
                    sumDay01+=31;
                    break;
                case 4:case 6:case 9:case 11:
                    sumDay01+=30;
                    break;
                case 2:
                    if (year%4==0&&year%100==0||year%400==0){
                        sumDay01+=29;
                    }else {
                        sumDay01+=28;
                    }
        }
        }
        switch(month){
            case 1:case 3:case 5:case 7:case 8:case 10:case 12:
                sumDay02+=31;
                break;
            case 4:case 6:case 9:case 11:
                sumDay02+=30;
                break;
            case 2:
                if (year%4==0&&year%100==0||year%400==0){
                    sumDay02+=29;
                }else {
                    sumDay02+=28;
                }
        }
        //week
        int week=sumDay01%7+1;
        if(week==0){
            week=7;
        }

        System.out.println(year+"年"+month+"月1日星期"+week);
        System.out.println("一t二t三t四t五t六t日");
        for (int i = 1; i < week; i++) {
            System.out.print("t");
            a++;
        }
        for (int i = 1; i <=sumDay02 ; i++) {
            System.out.print(i+"t");
            a++;
            if(a==7){
                System.out.println();
                a=0;
            }
        }
        }

}