125. 验证回文串

125. 验证回文串

class Solution {
    public boolean isPalindrome(String s) {
        if (s.equals(""))
            return true;
        StringBuffer str = new StringBuffer();
        for (int i = 0; i < s.length(); i++) {
            char ch = s.charAt(i);
            if (Character.isLetterOrDigit(ch)) {
                str.append(Character.toLowerCase(ch));
            }
        }
        StringBuffer strRev = new StringBuffer(str).reverse();
        return strRev.toString().equals(str.toString());
    }
}