Convert the byte to hex format

   public static void main(String[] args)
   {
      String toHash =
         "expire=1290777974mid=2865745secret=blablasid=1fa2773cd5451a627ebe63a6b3f1341b14ab7c5e866b01d808fee30ba2uQpzRxC856eUH5N8viXt";

      MessageDigest md = null;
      try
      {
         md = MessageDigest.getInstance("MD5");
      }
      catch (NoSuchAlgorithmException e)
      {
         e.printStackTrace();
      }

      byte[] mdbytes = md.digest(toHash.getBytes());

      long currentTimeMillis = System.currentTimeMillis();
      for (int k = 0; k < 10000; k++)
      {
         //convert the byte to hex format method 1
         StringBuffer sb2 = new StringBuffer();
         for (int i = 0; i < mdbytes.length; i++)
         {
            sb2.append(Integer.toString((mdbytes[i] & 0xff) + 0x100, 16).substring(1));
         }
         String string = sb2.toString();
         //         System.out.println("Digest(in hex format) 1 :: " + sb2.toString());
      }
      currentTimeMillis = System.currentTimeMillis() - currentTimeMillis;
      System.out.println(">>> alexey: .main currentTimeMillis = " + currentTimeMillis);

      currentTimeMillis = System.currentTimeMillis();
      for (int k = 0; k < 10000; k++)
      {
         //convert the byte to hex format method 2
         StringBuffer hexString = new StringBuffer();
         for (int i = 0; i < mdbytes.length; i++)
         {
            String hex = Integer.toHexString(0xff & mdbytes[i]);
            if (hex.length() == 1)
               hexString.append('0');
            hexString.append(hex);
         }
         String string = hexString.toString();
         //         System.out.println("Digest(in hex format) 2 :: " + hexString.toString());
      }
      currentTimeMillis = System.currentTimeMillis() - currentTimeMillis;
      System.out.println(">>> alexey: .main currentTimeMillis = " + currentTimeMillis);
   }

The result is
>>> alexey: .main currentTimeMillis = 223
>>> alexey: .main currentTimeMillis = 76