netty

public static void puback (Channel channel, MqttMessage mqttMessage) {

  MqttPublishMessage mqttPublishMessage = (MqttPublishMessage) mqttMessage;

  MqttFixedHeader mqttFixedHeaderInfo = mqttPublishMessage.fixedHeader();

  MqttQoS qos = (MqttQoS) mqttFixedHeaderInfo.qosLevel();

        byte[] headBytes = new byte[mqttPublishMessage.payload().readableBytes()];

        mqttPublishMessage.payload().readBytes(headBytes);

        String data = new String(headBytes);

        System.out.println("publish data--"+data);

 

        switch (qos) {

         case AT_MOST_ONCE: // 至多一次

             break;

         case AT_LEAST_ONCE: // 至少一次

       // 构建返回报文， 可变报头

       MqttMessageIdVariableHeader mqttMessageIdVariableHeaderBack = MqttMessageIdVariableHeader.from(mqttPublishMessage.variableHeader().packetId());

       // 构建返回报文， 固定报头

       MqttFixedHeader mqttFixedHeaderBack = new MqttFixedHeader(MqttMessageType.PUBACK,mqttFixedHeaderInfo.isDup(), MqttQoS.AT_MOST_ONCE, mqttFixedHeaderInfo.isRetain(), 0x02);

       // 构建PUBACK消息体

       MqttPubAckMessage pubAck = new MqttPubAckMessage(mqttFixedHeaderBack, mqttMessageIdVariableHeaderBack);

       log.info("back--"+pubAck.toString());

       channel.writeAndFlush(pubAck);

             break;

         case EXACTLY_ONCE: // 刚好一次

             // 构建返回报文， 固定报头

          MqttFixedHeader mqttFixedHeaderBack2 = new MqttFixedHeader(MqttMessageType.PUBREC,false, MqttQoS.AT_LEAST_ONCE,false,0x02);

             // 构建返回报文， 可变报头

             MqttMessageIdVariableHeader mqttMessageIdVariableHeaderBack2 = MqttMessageIdVariableHeader.from(mqttPublishMessage.variableHeader().packetId());

             MqttMessage mqttMessageBack = new MqttMessage(mqttFixedHeaderBack2,mqttMessageIdVariableHeaderBack2);

       log.info("back--"+mqttMessageBack.toString());

       channel.writeAndFlush(mqttMessageBack);

             break;

   default:

    break;

        }

 }