对String字符串进行反序输出

//1. 使用数组循环public static String array(String s){        int length=s.length();        char[] array=s.toCharArray();        for(int i=0;i<length/2;i++){            array[i]=s.charAt(length-1-i);            array[length-1-i]=s.charAt(i);        }        return new String(array);           }//2. StringBuffer的reverse方法public static StringBuffer buffer(String s){        StringBuffer sb=new StringBuffer();        sb.append(s);               return sb.reverse();    }//3. StringBuffer的循环        public static String buffer2(String s){        int length=s.length();        StringBuffer sb=new StringBuffer();        for(int i=s.length()-1;i>=0;i--){            sb.append(s.charAt(i));        }        return sb.toString();           } //StringBuilder比StringBuffer快，但线程不安全//4.栈的后进先出    public static String reverseByStack(String str) {          if(str == null || str.length() == 0) {              return str;          }          Stack<Character> strStack = new Stack<Character>();          char[] chArray = str.toCharArray();          for(Character ch: chArray) {              strStack.push(ch);          }          int len = str.length();          for(int i= 0; i< len; i++) {              chArray[i] = strStack.pop();          }          return new String(chArray);      }  5.  迭代完成    public static String reverseByRecursive(String str) {        if(str == null || str.length() == 0) {             return str;  }        int len = str.length();        if(len == 1) {           return str;        } else {  return reverseByRecursive(str.substring(1))+ str.charAt(0);          }      }