[Android]对字符串进行MD5加密

 /** 
      * 将字符串转成MD5值 
      *  
      * @param string 
      * @return 
      */  
     public static String stringToMD5(String string) {  
         byte[] hash;  
       
         try {  
             hash = MessageDigest.getInstance("MD5").digest(string.getBytes("UTF-8"));  
         } catch (NoSuchAlgorithmException e) {  
             e.printStackTrace();  
             return null;  
         } catch (UnsupportedEncodingException e) {  
             e.printStackTrace();  
             return null;  
         }  
       
         StringBuilder hex = new StringBuilder(hash.length * 2);  
         for (byte b : hash) {  
             if ((b & 0xFF) < 0x10)  
                 hex.append("0");  
             hex.append(Integer.toHexString(b & 0xFF));  
         }  
       
         return hex.toString();  
     }