1.最简单的方法:public static String reverse1(String str){ return new StringBuffer(str).reverse().toString();}2.最常用的方法:public static String reverse3(String s) { char[] array = s.toCharArray(); String reverse = ""; //注意这是空串,不是null for (int i = array.length - 1; i >= 0; i--) reverse += array[i]; return reverse; } 3.常用方法的变形: public static String reverse2(String s){ int length = s.length(); String reverse = ""; //注意这是空串,不是null for (int i = 0; i < length; i++) reverse = s.charAt(i) + reverse;//在字符串前面连接, 而非常见的后面 return reverse; }