用递归的方法，判断回文字符串

 

public class Palindrome {

    public static void main(String[] args) {

        String arr[] = { "abcdcba" , "abccba" , "abccbas" , "abcdacba" };

        for ( int i = 0; i < arr. length ; i++) {

            System. out .println(arr[i] + " = " + isPalindrome (arr[i].trim()));

        }

    }

    public static boolean isPalindrome(String str) {

        int len = str.length();

        if ( null == str || len < 1)

            return false ;

        char a = str.charAt(0);

        char b = str.charAt(len - 1);

        if (a != b)

            return false ;

        if (2 == len || 1 == len)

            return true ;

        return isPalindrome (str.substring(1, len - 1).trim());

    }

}