日期工具方法

1  public boolean isLeapYear(int year) {
2         return ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0));
3     }

 1 protected int getLastDayOfMonth(int monthNum, int year) {
 2 
 3         switch (monthNum) {
 4             case 1:
 5                 return 31;
 6             case 2:
 7                 return (isLeapYear(year)) ? 29 : 28;
 8             case 3:
 9                 return 31;
10             case 4:
11                 return 30;
12             case 5:
13                 return 31;
14             case 6:
15                 return 30;
16             case 7:
17                 return 31;
18             case 8:
19                 return 31;
20             case 9:
21                 return 30;
22             case 10:
23                 return 31;
24             case 11:
25                 return 30;
26             case 12:
27                 return 31;
28             default:
29                 throw new IllegalArgumentException("Illegal month number: "
30                         + monthNum);
31         }
32     }