LeetCode Problem #9 : Palindrome Number

Question:

Given an integer x, return true if x is a palindrome, and false otherwise.

Constraints:

(-2 ³¹ ) < n < (2 ³¹ - 1)

Initial Solution:

class Solution {
    public boolean isPalindrome(int x) {
        if(x < 0) return false;
        StringBuilder stringBuilder = new StringBuilder(Integer.toString(x));
        return stringBuilder.toString().contentEquals(stringBuilder.reverse());
    }
}

Peformance:

N / A