public static String MD5(String paramString)
  {
    try
    {
      if (isBlank(paramString))
        return null;
      MessageDigest localMessageDigest = MessageDigest.getInstance("MD5");
      localMessageDigest.update(paramString.getBytes("UTF-8"));
      byte[] arrayOfByte = localMessageDigest.digest();
      StringBuilder localStringBuilder = new StringBuilder();
      for (int i = 0; ; i++)
      {
        if (i >= 16)
          return localStringBuilder.toString();
        Object[] arrayOfObject = new Object[1];
        arrayOfObject[0] = Byte.valueOf(arrayOfByte[i]);
        localStringBuilder.append(String.format("%02x", arrayOfObject));
      }
    }
    catch (Exception localException)
    {
    }
    return null;
  }


这一段是md5的加密，求算法

什么意思。