java 字符串 asc 加密解密

    package com;  

    public class MD5Test {  

        /**
         * @param args
         */
        public static void main(String[] args) {
            System.out.println(decrypt("137%128%143%145%124%144%135%143%76%"));  

            System.out.println(encrypt("frontdev"));
        }  

        /**
           *用户名解密
           *@param ssoToken 字符串
           *@return String 返回加密字符串
          */
          public static String decrypt(String ssoToken)
          {
            try
            {
              String name = new String();
              java.util.StringTokenizer st=new java.util.StringTokenizer(ssoToken,"%");
              while (st.hasMoreElements()) {
                int asc =  Integer.parseInt((String)st.nextElement()) - 27;
                name = name + (char)asc;
              }  

              return name;
            }catch(Exception e)
            {
              e.printStackTrace() ;
              return null;
            }
          }  

          /**
           *用户名加密
           *@param ssoToken 字符串
           *@return String 返回加密字符串
          */
          public static String encrypt(String ssoToken)
          {
            try
            {
              byte[] _ssoToken = ssoToken.getBytes("ISO-8859-1");
              String name = new String();
             // char[] _ssoToken = ssoToken.toCharArray();
              for (int i = 0; i < _ssoToken.length; i++) {
                  int asc = _ssoToken[i];
                  _ssoToken[i] = (byte) (asc + 27);
                  name = name + (asc + 27) + "%";
              }
              return name;
            }catch(Exception e)
            {
              e.printStackTrace() ;
              return null;
            }
          }
    }