Reverse Integer

Reverse digits of an integer. 
Example1: x = 123, return 321 
Example2: x = -123, return -321

public class Solution {
    public int reverse(int x) {
       int positive = Math.abs(x);
       int res = 0;
       while(positive>0) {
           res = res *10 + positive % 10;
           positive = positive/10;
       }
       return x>=0? res: -res;
    }
}