Project Euler #4 solved in Java

Project Euler question 4 is:

A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 99.

Find the largest palindrome made from the product of two 3-digit numbers.

My solution is:

public class Euler4
{
    public boolean isPalindrome( String s )
    {
        //if odd length then remove middle character
        if ( s.length() % 2 != 0 )
        {
            s = s.substring( 0, s.length() / 2 ) + s.substring( (s.length() / 2) + 1);
        }         return new StringBuffer( s.substring( 0, s.length() / 2) ).
                                 reverse().toString().equals( s.substring( s.length() / 2) );
    }
} public static void main(String[] args)
{
    Euler4 e = new Euler4();
    long biggest = 0;     int a = 999, b = 999;
    for (int bb = b; bb > 0; bb--)
    {
        for (int aa = a; aa > 0; aa--)
        {
            if ( e.isPalindrome( new Long(aa*bb).toString() ) )
            {
                if ( aa*bb > biggest )
                {
                    biggest = aa*bb;
                }
            }
        }
    }     System.out.println(biggest);
}