【Java】使用switch 计算一个日期是当年的第几天

 1 import java.util.Scanner;
 2 
 3 /**
 4  * 计算一个日期是当年的第几天
 5  */
 6 public class CountDays {
 7 
 8 
 9     public static void main(String[] args) {
10         Scanner in = new Scanner(System.in);
11         int year,month,day;
12         int dayNumber =0;
13 
14         //input year month day
15         System.out.println("input  year month(1-12) day(1-31): ");
16         System.out.print("       ");
17         year  =  in.nextInt();
18         month =  in.nextInt();
19         day   =  in.nextInt();
20 
21         //判断闰年
22         boolean flag =false;
23         if ((year%4==0 && year%100 !=0) || year%400==0)
24         {
25             flag = true;
26         }
27         
28         //month
29         switch (month)
30         {
31         case 12:dayNumber +=30;
32         case 11:dayNumber +=31;
33         case 10:dayNumber +=30;
34         case 9 :dayNumber +=31;
35         case 8 :dayNumber +=31;
36         case 7 :dayNumber +=30;
37         case 6 :dayNumber +=31;
38         case 5 :dayNumber +=30;
39         case 4 :dayNumber +=31;
40         case 3 :if (flag)//闰年
41         {
42             dayNumber +=29;
43         }else
44             dayNumber +=28;
45         case 2 :dayNumber +=31;
46         case 1 :dayNumber +=day;break;
47         default:System.out.println("ERROR!");
48         }
49         System.out.println("dayNumber :"+dayNumber);
50     }
51     
52 }