Java Programming

I need a bit of help making a palindrome tester...

For those of you unfamiliar w/ palindromes its a word like so:

Raceacr

spelled the same way forward and backward...

so here is my code:

import java.util.*;
public class Palindrome
{
    
     public static void main(String[] args)
     {
         
         
         
         String deLimiters = ";:'<>,./?-+!@#$%^&*() ";
         Stack<String> stack = new Stack<String>();
         Scanner reader = new Scanner(System.in);
         
         while(true)
         {
            String palindrome = "";
            String backwards = "";
            
            System.out.println("Please enter a palindrome (Type n to quit): ");
            String str = reader.nextLine();
            
            if(str.equalsIgnoreCase("n"))
            {
                System.exit(0);
            }
         
         
            StringTokenizer tokens = new StringTokenizer(str, deLimiters);
            StringTokenizer tokens2 = new StringTokenizer(palindrome, deLimiters);
         
            
            while(tokens.hasMoreTokens())
            {
                 palindrome += tokens.nextToken();
            }
          
        
            for(int i = 0; i < palindrome.length(); i++)
            {
                 stack.add(palindrome.substring(i, i +1));   
            }
         
         
            while(! stack.empty())
            {
                backwards += stack.pop();
            }
        
       
            if(palindrome.equalsIgnoreCase(backwards))
            {
                System.out.println("Your phrase: " + palindrome + " is a Palindrome");
            }
            else
            {
                System.out.println("Your phrase: " + palindrome + " is not a Palindrome");
            }
        }
        
    }
}

i need some help just making it work...