Reverse Integer

 1 public class Solution {
 2     public int reverse(int x) {
 3
 7     
 8         if(x<0){//负数
 9             
10             long xx = x;
11             xx=xx*(-1);
12             if(xx>Integer.MAX_VALUE){
13                 //    System.out.println("///////");
14                     return 0;
15                 }
16         
17             Integer num = new Integer(x);
18             num=-num;
19             String s = num.toString();
20             StringBuilder sb = new StringBuilder(s);
21             sb.reverse();
22             String ss = sb.toString();
23             
24             if(Long.parseLong(ss)>Integer.MAX_VALUE){
25             //    System.out.println("///////");
26                 return 0;
27             }
28             int i = -Integer.parseInt(ss);
29             return i;
30             }
31         
32         else{//正数
35                 Integer num = new Integer(x);
36                 String s = num.toString();
37                 StringBuilder sb = new StringBuilder(s);
38                 sb.reverse();
39                 String ss = sb.toString();
40         
41         
42             if(Long.parseLong(ss)>Integer.MAX_VALUE){
43             //    System.out.println("///////");
44                 return 0;
45             }
46     
48             return Integer.parseInt(ss);
49             }
50         
51     }
52 
53 }