protected void internalStart()

in server/src/main/java/org/apache/calcite/avatica/server/HttpServer.java [217:270]
44 lines of code
12 McCabe index (conditional complexity)

  protected void internalStart() {
    if (server != null) {
      throw new RuntimeException("Server is already started");
    }

    final SubjectPreservingPrivilegedThreadFactory subjectPreservingPrivilegedThreadFactory =
        new SubjectPreservingPrivilegedThreadFactory();
    //The constructor parameters are the Jetty defaults, except for the ThreadFactory
    final QueuedThreadPool threadPool = new QueuedThreadPool(200, 8, 60000, -1, null, null,
        subjectPreservingPrivilegedThreadFactory);
    server = new Server(threadPool);
    server.manage(threadPool);

    ServerConnector serverConnector = null;
    HandlerList handlerList = null;
    if (null != this.config && AuthenticationType.CUSTOM == config.getAuthenticationType()) {
      if (null != handler || null != sslFactory) {
        throw new IllegalStateException("Handlers and SSLFactory cannot be configured with "
                + "the HTTPServer Builder when using CUSTOM Authentication Type.");
      }
    } else {
      serverConnector = configureServerConnector();
      handlerList = configureHandlers();
    }

    // Apply server customizers
    for (ServerCustomizer<Server> customizer : this.serverCustomizers) {
      LOG.info("Customizing server with customizer: " + customizer.getClass());
      customizer.customize(server);
    }

    try {
      server.start();
    } catch (Exception e) {
      throw new RuntimeException(e);
    }

    if (null != serverConnector && null != handlerList) {
      port = serverConnector.getLocalPort();
      LOG.info("Service listening on port {}.", getPort());

      // Set the information about the address for this server
      try {
        this.handler.setServerRpcMetadata(createRpcServerMetadata(serverConnector));
      } catch (UnknownHostException e) {
        // Failed to do the DNS lookup, bail out.
        throw new RuntimeException(e);
      }
    } else if (0 == server.getConnectors().length) {
      String error = "No server connectors have been configured for this Avatica server";
      LOG.error(error);
      throw new RuntimeException(error);
    }
  }