Valid Palindrome

1public boolean isPalindrome(String s) {
2    int left = 0;
3    int right = s.length() - 1;
4
5    while (left < right) {
6        if (!Character.isLetterOrDigit(s.charAt(left))) {
7            left++;
8            continue;
9        }
10        if (!Character.isLetterOrDigit(s.charAt(right))) {
11            right--;
12            continue;
13        }
14
15        if (Character.toLowerCase(s.charAt(left)) != Character.toLowerCase(s.charAt(right))) {
16            return false;
17        }
18
19        left++;
20        right--;
21    }
22
23    return true;
24}