PalindromeTest.java

public class Main {

    public static void main(String[] args) {
        System.out.println(isPalindrome("A man, a plan, a canal - Panama!"));
    }

    /**
     * Method to check if given string is a palindrome
     * @param sentence - sentence
     * @return boolean - if sentence is a palindrome 
     */
    public static boolean isPalindrome(String sentence){
        sentence = sentence.replaceAll("[^A-Za-z0-9]", "");
        sentence = sentence.toLowerCase();
        int start = 0;
        int end = sentence.length() - 1;
        while(start <= end){
            if (sentence.charAt(start) == sentence.charAt(end)){
                start ++;
                end --;
            } else {
                return false;
            }
        }
        return true;
    }
}