计算两个日期差

 1 public class 计算两个日期差 {
 2     // ********************计算两个日期差*******************
 3     static boolean if_run(int year) {// 判断是否为闰年函数
 4         boolean get = false;
 5         if (year % 4 == 0)
 6             get = true;
 7         if (year % 100 == 0)
 8             get = false;
 9         if (year % 400 == 0)
10             get = true;
11         return get;
12     }
13 
14     static int get_days(int year, int month, int day) {// 计算与基点日期的差
15         int sum = 0;
16         int[] a = { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
17         if (if_run(year))
18             a[2] += 1;
19         for (int i = 1; i < year; i++) {// 计算与基点日期差几年就加上相应的的天数
20             sum = sum + 365;
21             if (if_run(i))
22                 sum++;
23 
24         }
25         for (int i = 1; i < month; i++) {// 计算与基点日期差几月就加上相应的的天数
26             sum = sum + a[i];
27         }
28         sum = sum + day;// 计算与基点日期差几天就加上相应的的天数
29         return sum;
30 
31     }
32 
33     static int day_dif(int year1, int month1, int day1, int year2, int month2, int day2) {
34 
35         return get_days(year2, month2, day2) - get_days(year1, month1, day1);
36 
37     }
38 
39     public static void main(String[] args) {
40         int day = day_dif(1996, 11, 28, 2020, 1, 1);
41         System.out.println(day);
42     }
43 
44 }