判断闰年

 1 import java.util.Scanner;
 2 public class Date {
 3     private int year; // 年
 4     private int month; // 月
 5     private int day; // 日
 6     //有默认值的构造函数
 7     public Date() {
 8         year = 1000;
 9         month = 1;
10         day = 1;
11     }
12     // 判断是否为闰年
13     public int isleap() {
14         if (year % 400 == 0 || (year % 4 == 0 && year % 100 != 0)) {
15             return 1;
16         } else {
17             return 0;
18         }
19     }
20     // 判断日期是否合法
21     public int check() {
22         int m, n = 2;
23         m = isleap();
24         if (month > 12) {
25             n = 0;
26         }
27         if (month < 0 || year < 0 || day < 0) {
28             n = 0;
29         }
30         if (month == 1 || month == 3 || month == 5 || month == 7 || month == 8 || month == 10 || month == 12) {
31             if (day > 31)
32                 n = 0;
33             else
34                 n = 1;
35         }
36         if (month == 4 || month == 6 || month == 9 || month == 11) {
37             if (day > 30)
38                 n = 0;
39             else
40                 n = 1;
41         }
42         if (m == 1) {
43             if (month == 2 && day >= 30)
44                 n = 0;
45             if (month == 2 && day < 30)
46                 n = 1;
47         }
48         if (m == 0) {
49             if (month == 2 && day >= 29)
50                 n = 0;
51             if (month == 2 && day < 29)
52                 n = 1;
53         }
54         return n;
55     }
56     public void setDate() {
57         Scanner in = new Scanner(System.in);
58         System.out.print("请输入年月日：");
59         year = in.nextInt();
60         month = in.nextInt();
61         day = in.nextInt();
62     }
63     public void display() {
64         System.out.println(year + "-" + month + "-" + day);
65         int a, b;
66         a = isleap();
67         b = check();
68         if (b == 0) {
69             System.out.println("Error Date!");
70         } else if (b == 1) {
71             if (a == 1)
72                 System.out.println("Leap year");
73             if (a == 0)
74                 System.out.println("Common year");
75         }
76     }
77     public static void main(String[] args) {
78         Date d1 = new Date();
79         Date d2 = new Date();
80         d1.display();
81         d2.setDate();
82         d2.display();
83     }
84 }