java判断是否是回文字符

public class PalindromeTest {   public static void main(String[] args) {           isPalidrome("abcdedcba") ;    }   public static void isPalidrome(String str){       char[] ch = str.toCharArray();       int len = ch.length;       for (int i = 0, int j = len - 1; i <= j;) {           if (ch[i++] == ch[j--]) {           } else {                System.out.println("this string is not palindrome!");                break;          }       }   }}

?