package com.mall.common;public class Method {        public static void main(String args[]){        String str1="I am a student!";        System.out.println("原字符串：");        System.out.println(str1);        String str2=reverse(str1);        System.out.println("逆转后字符串：");        System.out.println(str2);        String s=",6,3,1";        System.out.println("原字符串 : "+s);        System.out.println("逆转后字符串："+wordReverse(s));   }    //单词逆转    public static String reverse(String str){        String[]strarray=str.split("\\s+");        StringBuffer sbf=new StringBuffer();        for(int i=strarray.length-1;i>=0;i--)        sbf.append(strarray[i]+" ");        return sbf.toString();    }    //字符逆转    public static String wordReverse(String str){           int n=str.length();           char []chars=new char[n];           str.getChars(0, n, chars, 0);//获得了char[]可操作的数组.                          int length=chars.length;           StringBuffer sbStr=new StringBuffer();           for(int i=0;i