code: public int getPort()
      {
          if (port != 0) {
              return port;
          }
          else {
              final Connector connector = connectorHolder.get();
              if (connector != null) {
                  Preconditions.checkState(connector.getLocalPort() > 0, "no port was set and the connector is not yet started!");
                  return connector.getLocalPort();
              }
              else {
                  return 0;
              }
          }
      }
docs: Returns the system port for this connector.