SpringBoot项目接入MQTT协议-编程知识

SpringBoot项目接入MQTT协议

mqtt是一种类似于mq的通讯技术

1、mqtt服务端搭建

创建docker网络

docker network create --driver bridge --subnet 172.18.0.0/24 --gateway 172.18.0.1 emqx-net

创建容器

docker run -d \--name emqx1 \-e "EMQX_NODE_NAME=emqx@172.18.0.2" \--network emqx-net \--ip 172.18.0.2 \--network-alias 172.18.0.2 \-p 1883:1883 \-p 8083:8083 \-p 8084:8084 \-p 8883:8883 \-p 18083:18083 \emqx/emqx:5.4.1docker run -d \--name emqx2 \--ip 172.18.0.3 \-e "EMQX_NODE_NAME=emqx@172.18.0.3" \--network emqx-net \--network-alias 172.18.0.3 \emqx/emqx:5.4.1docker run -d \--name emqx3 \--ip 172.18.0.4 \-e "EMQX_NODE_NAME=emqx@172.18.0.4" \--network emqx-net \--network-alias 172.18.0.4 \emqx/emqx:5.4.1

服务节点注册

docker exec -it emqx2 \
emqx ctl cluster join emqx@172.18.0.2docker exec -it emqx3 \
emqx ctl cluster join emqx@172.18.0.2

2、创建springboot项目，并增加mqtt依赖

依赖引入

<dependency><groupId>com.hivemq</groupId><artifactId>hivemq-mqtt-client</artifactId><version>1.3.0</version>
</dependency>
<dependency><groupId>com.alibaba</groupId><artifactId>fastjson</artifactId><version>1.2.83</version>
</dependency>

创建连接器

@Configuration
public class VideoConfig implements MqttClientDisconnectedListener, MqttClientConnectedListener {static Logger logger = LoggerFactory.getLogger(VideoConfig.class);@Value("${mqtt.server.url:192.168.31.47}")private String serverUrl;//mqtt地址@Value("${mqtt.server.port:1883}")private Integer serverPort;//mqtt地址@Value("${mqtt.server.username}")private String serverUserName;//mqtt账号（测试默认没有）@Value("${mqtt.server.password}")private String serverPassWord;//mqtt密码（测试默认没有）@Autowiredprivate DefautMqttConsumerListener defautMqttConsumerListener;@Beanpublic Mqtt3AsyncClient mqtt3AsyncClient(){String clientId = String.format("%d%s", TimeUtil.getCurrentInMillis(), RandomUtil.getRandomStr(10));Mqtt3ClientBuilder mqttClientBuilder = Mqtt3Client.builder();Mqtt3AsyncClient mqttClient = mqttClientBuilder.identifier(clientId).serverHost(serverUrl).serverPort(serverPort).addConnectedListener(this).addDisconnectedListener(this).build().toAsync();mqttClient.connect();mqttClient.connectWith().keepAlive(60).willPublish().topic("/").applyWillPublish().simpleAuth().username(serverUserName).password(serverPassWord.getBytes()).applySimpleAuth().send().whenCompleteAsync((connAck, throwable) -> {Mqtt3ConnAckReturnCode returnCode = connAck.getReturnCode();logger.info("mqtt connect result: {}", returnCode);if (throwable != null) {logger.error("connectWith error , throwable :"+throwable);}});return mqttClient;}/***连接成功回调后 监听mqtt消息**/@Overridepublic void onConnected(MqttClientConnectedContext mqttClientConnectedContext) {String subscribedTopic ="+/reply";//+表示匹配一个信息mqtt3AsyncClient().subscribeWith().topicFilter(subscribedTopic).callback(defautMqttConsumerListener).send().whenComplete((subAck, throwable) -> {if (throwable != null) {logger.error("Handle failure to subscribe", throwable);} else {logger.info("successful subscription: " + subscribedTopic);}});}/***连接关闭回调重新创建连接**/@Overridepublic void onDisconnected(MqttClientDisconnectedContext mqttClientDisconnectedContext) {final Mqtt3ClientDisconnectedContext context = (Mqtt3ClientDisconnectedContext) mqttClientDisconnectedContext;try {context.getReconnector().connectWith().simpleAuth().username(serverUserName).password(serverPassWord.getBytes()).applySimpleAuth().applyConnect().reconnect(true).delay(new Random().nextInt(100), TimeUnit.MILLISECONDS);} catch (Exception e) {logger.error("reconnect:" + e.getMessage(), e);}}
}

监听器

@Component
public class DefautMqttConsumerListener implements Consumer<Mqtt3Publish> {private static final Logger logger = LoggerFactory.getLogger(DefautMqttConsumerListener.class);@Overridepublic void accept(Mqtt3Publish mqttPublish) {String topic = mqttPublish.getTopic().toString();byte[] msg = mqttPublish.getPayloadAsBytes();String msgJson = new String(msg);logger.info("mqtt listener topic :{} ,msg:{}" ,topic, msgJson);}}

消息发送

public void sendMqttMsg(String topic, MqttQos qos, String msg){mqtt3AsyncClient.publishWith().topic(topic).payload(msg.getBytes()).qos(Optional.ofNullable(qos).orElse(MqttQos.AT_LEAST_ONCE)).retain(false).send().whenComplete((result, throwable) -> {logger.info("sendMqttMsg to video, topic : {} , body : {}",topic,body);if (throwable != null) {logger.error("transfer failed , throwable :{}",throwable);}});}