基于SpringBoot实现MQTT消息收发

以下是一个使用Spring Boot和MQTT的简单例子，展示了如何实现MQTT消息的发送和接收。

首先，添加依赖到你的pom.xml：

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.integration</groupId>
        <artifactId>spring-integration-stream</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.integration</groupId>
        <artifactId>spring-integration-mqtt</artifactId>
    </dependency>
</dependencies>

然后，配置MQTT客户端并发送接收消息：

@Configuration
public class MqttConfig {
 
    @Value("${mqtt.broker.url}")
    private String brokerUrl;
 
    @Value("${mqtt.client.id}")
    private String clientId;
 
    @Value("${mqtt.username}")
    private String userName;
 
    @Value("${mqtt.password}")
    private String password;
 
    @Bean
    public MqttPahoClientFactory mqttClientFactory() {
        DefaultMqttPahoClientFactory factory = new DefaultMqttPahoClientFactory();
        MqttConnectOptions options = new MqttConnectOptions();
        options.setServerURIs(new String[]{brokerUrl});
        options.setUserName(userName);
        options.setPassword(password.toCharArray());
        factory.setConnectionOptions(options);
        return factory;
    }
 
    @Bean
    public MqttMessagingTemplate mqttMessagingTemplate(MqttPahoClientFactory factory) {
        return new MqttMessagingTemplate(factory);
    }
}
 
@Service
public class MqttService {
 
    @Autowired
    private MqttMessagingTemplate mqttMessagingTemplate;
 
    public void sendMessage(String topic, String payload) {
        mqttMessagingTemplate.convertAndSend(topic, payload);
    }
 
    @Autowired
    private SimpMessagingTemplate simpMessagingTemplate;
 
    @JmsListener(topics = "myTopic")
    public void receiveMessage(String payload) {
        simpMessagingTemplate.convertAndSend("/topic/public", payload);
    }
}

在application.properties中配置MQTT参数：

mqtt.broker.url=tcp://localhost:1883
mqtt.client.id=myClientId
mqtt.username=myUserName
mqtt.password=m