code: public static String getCanonicalizedURI(String uri, boolean canonicalizePath) {
          String canonicalURI = uri;
          if (uri != null) {
              String host = getHost(uri);
              String path = getPath(uri);
              final boolean emptyPath = "".equals(path);
              final boolean noPathToCanonicalize = canonicalizePath && (path == null || emptyPath);
              final boolean trailingSlashPath = "/".equals(path);
              final String scheme = getScheme(uri);
              final boolean pathlessScheme = "ssl".equals(scheme) || "tcp".equals(scheme) || "pipe".equals(scheme)
                      || "udp".equals(scheme) || "mux".equals(scheme);
              final boolean trailingSlashWithPathlessScheme = trailingSlashPath && pathlessScheme;
              String newPath = trailingSlashWithPathlessScheme ? "" :
                               noPathToCanonicalize ? (pathlessScheme ? null : "/") : null;
              if (((host != null) && !host.equals(host.toLowerCase())) || newPath != null) {
                  path = newPath == null ? path : newPath;
                  try {
                      canonicalURI = buildURIAsString(scheme, getUserInfo(uri), host == null ?
                              null : host.toLowerCase(), getPort(uri), path, getQuery(uri), getFragment(uri));
                  } catch (URISyntaxException ex) {
                      throw new IllegalArgumentException("Invalid URI: " + uri + " in Gateway configuration file", ex);
                  }
              }
          }
          return canonicalURI;
      }
docs: Create a canonical URI from a given URI.   A canonical URI is a URI with:<ul> <li>the host part of the authority
  lower-case since URI semantics dictate that hostnames are case insensitive <li>(optionally, NOT appropriate for Origin
  headers) the path part set to "/" except for tcp uris if there was no path in the input URI (this conforms to the
  WebSocket and HTTP protocol specifications and avoids us having to do special handling for path throughout the server
  code). </ul>
  
  @param uri              the URI to canonicalize
  @param canonicalizePath if true, append trailing '/' when missing
  @return a URI with the host part of the authority lower-case and (optionally if not tcp) trailing / added, or null if the
  uri is null
  @throws IllegalArgumentException if the uri is not valid syntax