public void execute()

in gateway-server/src/main/java/org/apache/knox/gateway/util/KnoxCLI.java [2013:2121]
95 lines of code
18 McCabe index (conditional complexity)

    public void execute() {
      attempts++;
      CloseableHttpClient client;
      String http = "http://";
      String https = "https://";
      GatewayConfig conf = getGatewayConfig();
      String gatewayPort;
      String host;

      if(cluster == null) {
        printKnoxShellUsage();
        out.println("A --cluster argument is required.");
        return;
      }

      if(hostname != null) {
        host = hostname;
      } else {
        try {
          host = InetAddress.getLocalHost().getHostName();
        } catch (UnknownHostException e) {
          out.println(e.toString());
          out.println("Defaulting address to localhost. Use --hostname option to specify a different hostname");
          host = "localhost";
        }
      }

      if (port != null) {
        gatewayPort = port;
      } else if (conf.getGatewayPort() > -1) {
        gatewayPort = Integer.toString(conf.getGatewayPort());
      } else {
        out.println("Could not get port. Please supply it using the --port option");
        return;
      }


      String path = "/" + conf.getGatewayPath();
      String topology = "/" + cluster;
      String httpServiceTestURL = http + host + ":" + gatewayPort + path + topology + "/service-test";
      String httpsServiceTestURL = https + host + ":" + gatewayPort + path + topology + "/service-test";

      String authString = "";
//    Create Authorization String
      if( user != null && pass != null) {
        authString = "Basic " + Base64.encodeBase64String((user + ":" + pass).getBytes(StandardCharsets.UTF_8));
      } else {
        out.println("Username and/or password not supplied. Expect HTTP 401 Unauthorized responses.");
      }

//    Initialize the HTTP client
      client = HttpClients.createDefault();

      HttpGet request;
      if(ssl) {
        request = new HttpGet(httpsServiceTestURL);
      } else {
        request = new HttpGet(httpServiceTestURL);
      }

      request.setHeader("Authorization", authString);
      request.setHeader("Accept", MediaType.APPLICATION_JSON.getMediaType());
      try {
        out.println(request.toString());
        try(CloseableHttpResponse response = client.execute(request)) {

          switch (response.getStatusLine().getStatusCode()) {

          case 200:
            response.getEntity().writeTo(out);
            break;
          case 404:
            out.println("Could not find service-test resource");
            out.println("Make sure you have configured the SERVICE-TEST service in your topology.");
            break;
          case 500:
            out.println("HTTP 500 Server error");
            break;

          default:
            out.println("Unexpected HTTP response code.");
            out.println(response.getStatusLine().toString());
            response.getEntity().writeTo(out);
            break;
          }
        }
        request.releaseConnection();
      } catch (ClientProtocolException e) {
        out.println(e.toString());
        if (debug) {
          e.printStackTrace(out);
        }
      } catch (SSLException e) {
        out.println(e.toString());
        retryRequest();
      } catch (IOException e) {
        out.println(e.toString());
        retryRequest();
        if(debug) {
          e.printStackTrace(out);
        }
      } finally {
        try {
          client.close();
        } catch (IOException e) {
          out.println(e.toString());
        }
      }
    }