I cannot send message to MQTT broker

[SoonyangZhang]

Hi ,Is there something wrong? The is no reaction when I send message data to MQTT broker.But the client did connect to the Broker. It seems there are bugs. The code connect Server in asynchronous way with netty. So when I send message with the method publish(String topic, ByteBuf payload),the parameter of channel is null.

[AYWWWWW]

publish是发布消息，你要接收消息，需要用on来订阅这个topic，其中的参数MqttHandler hanler是一个接口实现，在这个接口实现中写自己的onMessage方法。
/** * Subscribe on the given topic, with the given qos. When a message is received, MqttClient will invoke the {@link MqttHandler#onMessage(String, ByteBuf)} function of the given handler * This subscribtion is only once. If the MqttClient has received 1 message, the subscribtion will be removed * * @param topic The topic filter to subscribe to * @param handler The handler to invoke when we receive a message * @param qos The qos to request to the server * @return A future which will be completed when the server acknowledges our subscribe request */ @Override public Future<Void> once(String topic, MqttHandler handler, MqttQoS qos) { return createSubscribtion(topic, handler, true, qos); }