protected synchronized String getMatchedBackendURL()

in gateway-server/src/main/java/org/apache/knox/gateway/websockets/GatewayWebsocketHandler.java [207:281]
59 lines of code
10 McCabe index (conditional complexity)

  protected synchronized String getMatchedBackendURL(final URI requestURI) {
    final String path = requestURI.getRawPath();
    final String query = requestURI.getRawQuery();

    final ServiceRegistry serviceRegistryService = services
        .getService(ServiceType.SERVICE_REGISTRY_SERVICE);

    final ServiceDefinitionRegistry serviceDefinitionService = services
        .getService(ServiceType.SERVICE_DEFINITION_REGISTRY);

    /* Filter out the /cluster/topology to get the context we want */
    String[] pathInfo = path.split(REGEX_SPLIT_CONTEXT);

    final ServiceDefEntry entry = serviceDefinitionService
        .getMatchingService(pathInfo[1]);

    if (entry == null) {
      throw new RuntimeException(
          String.format(Locale.ROOT, "Cannot find service for the given path: %s", path));
    }

    /* Filter out /cluster/topology/service to get endpoint */
    String[] pathService = path.split(REGEX_SPLIT_SERVICE_PATH);

    /* URL used to connect to websocket backend */
    String backendURL = urlFromServiceDefinition(serviceRegistryService, entry, path);
    LOG.debugLog("Url obtained from services definition: " + backendURL);

    StringBuilder backend = new StringBuilder();
    try {
      if (StringUtils.containsAny(backendURL, WEBSOCKET_PROTOCOL_STRING, SECURE_WEBSOCKET_PROTOCOL_STRING)) {
        LOG.debugLog("ws or wss protocol found in service url");
        URI serviceUri = new URI(backendURL);
        backend.append(serviceUri);
        String pathSuffix = generateUrlSuffix(backend.toString(), pathService);
        backend.append(pathSuffix);
      } else if (StringUtils.containsAny(requestURI.toString(), WEBSOCKET_PROTOCOL_STRING, SECURE_WEBSOCKET_PROTOCOL_STRING)) {
        LOG.debugLog("ws or wss protocol found in request url");
        URL serviceUrl = new URL(backendURL);
        final String protocol = (serviceUrl.getProtocol().equals("https")) ? "wss" : "ws";
        backend.append(protocol).append("://");
        backend.append(serviceUrl.getHost()).append(':');
        backend.append(serviceUrl.getPort()).append('/');
        backend.append(serviceUrl.getPath());
        String pathSuffix = generateUrlSuffix(backend.toString(), pathService);
        backend.append(pathSuffix);
      } else {
        LOG.debugLog("ws or wss protocol not found in service url or request url");
        URL serviceUrl = new URL(backendURL);

        /* Use http host:port if ws url not configured */
        final String protocol = (serviceUrl.getProtocol().equals("ws")
                || serviceUrl.getProtocol().equals("wss")) ? serviceUrl.getProtocol()
                : "ws";
        backend.append(protocol).append("://");
        backend.append(serviceUrl.getHost()).append(':');
        backend.append(serviceUrl.getPort()).append('/');
        backend.append(serviceUrl.getPath());
      }
      /* in case we have query params */
      if(!StringUtils.isBlank(query)) {
        backend.append('?').append(query);
      }
      backendURL = backend.toString();

    } catch (MalformedURLException e){
        LOG.badUrlError(e);
        throw new RuntimeException(e.toString());
    } catch (Exception  e1) {
        LOG.failedCreatingWebSocket(e1);
        throw new RuntimeException(e1.toString());
    }

    return backendURL;
  }