// region MqttActionCallBack -- connection success or fail
 @Override
 public void onSuccess(IMqttToken iMqttToken) {
   isConnected = true;
   ShowToast("连ζŽ₯成功");
   try {
     client.subscribe("Likaci/MqttMap", 0);
   } catch (MqttException e) {
     e.printStackTrace();
   }
 }
  @Override
  protected void init(VaadinRequest request) {
    System.out.println("request = " + request);
    final VerticalLayout layout = new VerticalLayout();
    layout.setMargin(true);
    setContent(layout);
    layout.addComponent(chart);

    try {
      empf = new MqttClient("tcp://192.168.0.106:1883", "MyfirstMQTTEmpf", new MemoryPersistence());
      empf.setCallback(
          new MqttCallback() {
            @Override
            public void connectionLost(Throwable throwable) {}

            @Override
            public void messageArrived(String str, MqttMessage mqttMessage) throws Exception {
              byte[] payload = mqttMessage.getPayload();
              lastMessage = new String(payload);
              System.out.println("s = " + str + " msg " + lastMessage);
            }

            @Override
            public void deliveryComplete(IMqttDeliveryToken iMqttDeliveryToken) {}
          });

      Button button = new Button("refresh");
      button.addClickListener(
          event ->
              access(
                  () ->
                      chart
                          .getConfiguration()
                          .getSeries()
                          .forEach(
                              s ->
                                  ((ListSeries) s)
                                      .updatePoint(0, Double.valueOf(lastMessage.split(":")[3])))));
      layout.addComponent(button);
      empf.connect();
      empf.subscribe(TOPIC, 1);

      mqqtThread.start();
    } catch (MqttException e) {
      e.printStackTrace();
    }
  }