springboot项目怎么集成mqtt

Spring Boot项目集成MQTT主要有以下几个步骤：

1. 在pom.xml文件中添加MQTT客户端的依赖，例如eclipse-paho的mqtt-client。

<dependency>
    <groupId>org.eclipse.paho</groupId>
    <artifactId>mqtt-client</artifactId>
    <version>1.2.0</version>
</dependency>

2. 配置MQTT客户端的连接参数，例如服务器host、port、用户名、密码等。

# MQTT broker配置
mqtt.broker.host=tcp://localhost
mqtt.broker.port=1883
mqtt.broker.username=
mqtt.broker.password=

3. 创建MQTT客户端连接工厂并设置连接参数。

@Configuration
public class MqttConfig {

    @Value("${mqtt.broker.host}")
    private String brokerHost;

    @Value("${mqtt.broker.port}")
    private int brokerPort;

    @Value("${mqtt.broker.username}")
    private String username;

    @Value("${mqtt.broker.password}")
    private String password;

    @Bean
    public MqttConnectOptions getMqttConnectOptions() {
        MqttConnectOptions mqttConnectOptions = new MqttConnectOptions();
        mqttConnectOptions.setUserName(username);
        mqttConnectOptions.setPassword(password.toCharArray());
        mqttConnectOptions.setCleanSession(true);
        mqttConnectOptions.setConnectionTimeout(10);
        mqttConnectOptions.setKeepAliveInterval(20);
        return mqttConnectOptions;
    }

    @Bean
    public MqttClient mqttClient() throws MqttException {
        MqttAsyncClient mqttClient = new MqttAsyncClient(brokerHost + ":" + brokerPort, MqttAsyncClient.generateClientId(), new MemoryPersistence());
        mqttClient.connect(getMqttConnectOptions()).waitForCompletion();
        return mqttClient;
    }
}

4. 创建MQTT消息处理器，例如收到消息后打印出来。

@Component
public class MqttMessageHandler implements MqttCallback {

    private static final Logger logger = LoggerFactory.getLogger(MqttMessageHandler.class);

    @Override
    public void connectionLost(Throwable cause) {
        logger.error("MQTT connection lost.", cause);
    }

    @Override
    public void messageArrived(String topic, MqttMessage message) throws Exception {
        logger.info("Received message from topic [{}]: {}", topic, new String(message.getPayload()));
    }

    @Override
    public void deliveryComplete(IMqttDeliveryToken token) {
        logger.info("MQTT message delivery complete.");
    }
}

5. 订阅MQTT主题，并指定消息处理器。

@Service
public class MqttService {

    private static final Logger logger = LoggerFactory.getLogger(MqttService.class);

    private final MqttClient mqttClient;

    private final MqttMessageHandler mqttMessageHandler;

    @Value("${mqtt.topic}")
    private String topic;

    public MqttService(MqttClient mqttClient, MqttMessageHandler mqttMessageHandler) throws MqttException {
        this.mqttClient = mqttClient;
        this.mqttMessageHandler = mqttMessageHandler;
        mqttClient.setCallback(mqttMessageHandler);
        mqttClient.subscribe(topic, 1);
        logger.info("Subscribed to topic [{}].", topic);
    }
}

6. 发布MQTT消息。

@Service
public class MqttService {

    private static final Logger logger = LoggerFactory.getLogger(MqttService.class);

    private final MqttClient mqttClient;

    private final MqttMessageHandler mqttMessageHandler;

    @Value("${mqtt.topic}")
    private String topic;

    public MqttService(MqttClient mqttClient, MqttMessageHandler mqttMessageHandler) throws MqttException {
        this.mqttClient = mqttClient;
        this.mqttMessageHandler = mqttMessageHandler;
        mqttClient.setCallback(mqttMessageHandler);
        mqttClient.subscribe(topic, 1);
        logger.info("Subscribed to topic [{}].", topic);
    }

    public void publish(String message) throws MqttException {
        MqttMessage mqttMessage = new MqttMessage(message.getBytes());
        mqttClient.publish(topic, mqttMessage);
        logger.info("MQTT message published to topic [{}]: {}", topic, message);
    }
}

以上就是Spring Boot项目集成MQTT的基本步骤，具体实现方式可以根据实际情况进行调整。