code: @Nullable
    public static URI getAsURI (@Nullable final URL aURL)
    {
      if (aURL != null)
        try
        {
          return aURL.toURI ();
        }
        catch (final URISyntaxException ex)
        {
          // fall-through
          if (GlobalDebug.isDebugMode ())
            if (LOGGER.isWarnEnabled ())
              LOGGER.warn ("Debug warn: failed to convert '" + aURL + "' to a URI!");
        }
      return null;
    }
docs: Get the passed URL as an URI. If the URL is null or not an URI
  <code>null</code> is returned.
  
  @param aURL
  Source URL. May be <code>null</code>.
  @return <code>null</code> if the passed URL is empty or invalid.