import java.util.Scanner; public class LeapYear1 {          public static boolean isleapyear(int year) {         return (year%4==0&&year%100!=0)||year%400==0 ?  true:false;     }     public static void main(String[] args) {                  Scanner sc = new Scanner(System.in);                  System.out.println("请输入一个年份：");         int year;         while(sc.hasNext()) {             year = sc.nextInt();             if(year<0)                 System.out.println("输入的年份有误！");             else {                 System.out.println(year+"年"+(isleapyear(year) ? "是闰年":"是平年"));             }         }sc.close();     } } //初学者，麻烦有人帮我看下，写的有什么瑕疵吗？