code: public void start() throws Exception {
          // verify server is NOT null
          if (server == null) {
              throw new NullPointerException("Internal server instance was null, server not configured perhaps?");
          }
  
          logger.info("HttpServer [{}] version [{}] using Jetty [{}]", configuration.safeGetName(), com.cloudhopper.jetty.Version.getLongVersion(),
  		    server.getVersion());
          logger.info("HttpServer [{}] on [{}] starting...", configuration.safeGetName(), configuration.getPortString());
  
          // try to start jetty server -- if it fails, it'll actually keep running
          // so if an exception occurs, we'll make to stop it afterwards and rethrow the exception
          try {
              server.start();
          } catch (Exception e) {
              // make sure we stop the server
              try { this.stop(); } catch (Exception ex) { }
              throw e;
          }
  
          logger.info("HttpServer [{}] on [{}] started", configuration.safeGetName(), configuration.getPortString());
      }
docs: Starts the HTTP server.  If an exception is thrown during startup, Jetty
  usually still runs, but this method will catch that and make sure it's
  shutdown before re-throwing the exception.
  @throws Exception Thrown if there is an error during start