判断一个字符串是否是回文。回文是指：字符串从左向右读与从右向左度是一样的。

import java.util.Arrays;

public class ExamDemo {

       public static void main(String[] args){

              String s = args[0];

              char[] str = s.toCharArray();

              int i;

              for (i = 0; i < str.length / 2; i++){

                     if (str[i] != str[str.length - i - 1])

                            break;

              }

              if (i == str.length / 2)

                     System.out.println("字符串" + args[0] + "是回文");

              else

                     System.out.println("字符串" + args[0] + "不是回文");

       }

}