Springboot如何使用MQTT

Spring Boot 可以通过集成 Eclipse Paho 客户端包来使用 MQTT。下面是使用 Eclipse Paho 客户端包在 Spring Boot 中集成 MQTT 的简单步骤：

1.添加 Eclipse Paho 客户端包依赖

<dependency>
    <groupId>org.eclipse.paho</groupId>
    <artifactId>org.eclipse.paho.client.mqttv3</artifactId>
    <version>1.2.2</version>
</dependency>

2.编写 MQTT 客户端配置类

@Configuration
public class MqttConfiguration {

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

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

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

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

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

    @Value("${mqtt.qos}")
    private int qos;

    @Bean
    public MqttConnectOptions getMqttConnectOptions() {
        MqttConnectOptions mqttConnectOptions = new MqttConnectOptions();
        mqttConnectOptions.setUserName(username);
        mqttConnectOptions.setPassword(password.toCharArray());
        mqttConnectOptions.setServerURIs(new String[] { brokerUrl });
        mqttConnectOptions.setCleanSession(true);
        mqttConnectOptions.setKeepAliveInterval(60);
        mqttConnectOptions.setConnectionTimeout(60);
        mqttConnectOptions.setAutomaticReconnect(true);
        mqttConnectOptions.setWill(topic, "disconnected".getBytes(), qos, true);
        return mqttConnectOptions;
    }

    @Bean
    public MqttClient getMqttClient() throws MqttException {
        MqttClient mqttClient = new MqttClient(brokerUrl, clientId);
        mqttClient.connect(getMqttConnectOptions());
        return mqttClient;
    }
}

3.使用 MQTT 客户端发送消息

@RestController
public class MqttController {

    @Autowired
    private MqttClient mqttClient;

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

    @Value("${mqtt.qos}")
    private int qos;

    @PostMapping("/mqtt")
    public void sendMessage(@RequestBody String message) throws MqttException {
        MqttMessage mqttMessage = new MqttMessage();
        mqttMessage.setPayload(message.getBytes());
        mqttMessage.setQos(qos);
        mqttClient.publish(topic, mqttMessage);
    }
}

以上是使用 Eclipse Paho 客户端包在 Spring Boot 中集成 MQTT 的简单步骤。