Java实现万年历查询程序

String againString = "";
Scanner input= new Scanner(System.in);
do{
String xunhuan = "";
do{
System.out.println("\t******请输入用户名及密码：********");
        System.out.print("\t请输入用户名：");     
          String userName=input.next();
        System.out.println("\t请输入密　码：");
        String passwold=input.next();
        if("admin".equals(userName)&&"123".equals(passwold)){       
          break;
        }else{
                System.out.println("密码或用户名错误，请重新输入");
             System.out.println("继续按y，返回请安任意键");
             }         
         xunhuan = input.next().toLowerCase();
         if(!"y".equals(xunhuan)){
          System.out.println("谢谢使用万年历系统。祝您心情愉快");
          return;           
         }
      }while(xunhuan.equals("y"));
            System.out.println("\t****欢迎进入万年历系统――――――――编辑:仰望猪****");
System.out.println("请输入年份");
int Year=input.nextInt();
System.out.println("请输入月份");
int Month=input.nextInt();
int Numbersum=0;
for(int Numberday=1900; Numberday<Year;Numberday++){
if(Numberday%4==0&&Numberday%100!=0||Numberday%400==0){