判断闰年

1.目标：根据输入的年月日判断是否为闰年

2.代码：

import java.util.Scanner;
public class Date {
    private int year; // 年
    private int month; // 月
    private int day; // 日
    //有默认值的构造函数
    public Date() {
        year = 1000;
        month = 1;
        day = 1;
    }
    // 判断是否为闰年
    public int isleap() {
        if (year % 400 == 0 || (year % 4 == 0 && year % 100 != 0)) {
            return 1;
        } else {
            return 0;
        }
    }
    // 判断日期是否合法
    public int check() {
        int m, n = 2;
        m = isleap();
        if (month > 12) {
            n = 0;
        }
        if (month < 0 || year < 0 || day < 0) {
            n = 0;
        }
        if (month == 1 || month == 3 || month == 5 || month == 7 || month == 8 || month == 10 || month == 12) {
            if (day > 31)
                n = 0;
            else
                n = 1;
        }
        if (month == 4 || month == 6 || month == 9 || month == 11) {
            if (day > 30)
                n = 0;
            else
                n = 1;
        }
        if (m == 1) {
            if (month == 2 && day >= 30)
                n = 0;
            if (month == 2 && day < 30)
                n = 1;
        }
        if (m == 0) {
            if (month == 2 && day >= 29)
                n = 0;
            if (month == 2 && day < 29)
                n = 1;
        }
        return n;
    }
    public void setDate() {
        Scanner in = new Scanner(System.in);
        System.out.print("请输入年月日：");
        year = in.nextInt();
        month = in.nextInt();
        day = in.nextInt();
    }
    public void display() {
        System.out.println(year + "-" + month + "-" + day);
        int a, b;
        a = isleap();
        b = check();
        if (b == 0) {
            System.out.println("Error Date!");
        } else if (b == 1) {
            if (a == 1)
                System.out.println("Leap year");
            if (a == 0)
                System.out.println("Common year");
        }
    }
    public static void main(String[] args) {
        Date d1 = new Date();
        Date d2 = new Date();
        d1.display();
        d2.setDate();
        d2.display();
    }
}

3.测试截图