code: private static String normalizeURL(String urlString)
              throws MalformedURLException {
          URL url = new URL(urlString);
          if (url.getPort() == -1) {
              return url.getProtocol() + "://" + url.getHost() + ":"
                      + url.getDefaultPort() + url.getFile()
                      + (url.getRef() != null ? "#" + url.getRef() : "");
          } else {
              return urlString;
          }
      }
docs: Return a URL string in which the port is always specified.