springboot 怎么用rabbitmq的mqtt发送消息

Spring Boot提供了Spring Integration项目，可以方便地将RabbitMQ和MQTT连接起来，并实现消息的发送和接收。

首先，在pom.xml文件中添加下面的依赖：

<dependency>
    <groupId>org.springframework.integration</groupId>
    <artifactId>spring-integration-mqtt</artifactId>
    <version>5.5.0</version>
</dependency>

然后，在application.properties文件中添加RabbitMQ和MQTT的配置：

spring.rabbitmq.host=your_rabbitmq_host
spring.rabbitmq.port=your_rabbitmq_port
spring.rabbitmq.username=your_rabbitmq_username
spring.rabbitmq.password=your_rabbitmq_password
spring.rabbitmq.virtual-host=your_rabbitmq_virtual_host

spring.mqtt.broker-url=tcp://your_mqtt_host:your_mqtt_port
spring.mqtt.username=your_mqtt_username
spring.mqtt.password=your_mqtt_password

接下来，创建一个RabbitMQ和MQTT进行交互的Service：

@Service
public class MqttRabbitMQService {

    @Autowired
    private MqttPahoClientFactory mqttClientFactory;

    @Autowired
    private AmqpTemplate amqpTemplate;

    public void sendMqttMessageToRabbitMQ(String topic, String payload) {
        Message<String> message = MessageBuilder
                .withPayload(payload)
                .setHeader(MqttHeaders.TOPIC, topic)
                .setHeader(MqttHeaders.QOS, 2)
                .build();
        mqttClientFactory.getClientInstance().publish(topic, message);
    }

    public void sendRabbitMQMessageToMqtt(String exchange, String routingKey, String payload) {
        amqpTemplate.convertAndSend(exchange, routingKey, payload);
    }
}

其中，sendMqttMessageToRabbitMQ()方法用于将MQTT消息发送到RabbitMQ，sendRabbitMQMessageToMqtt()方法用于将RabbitMQ消息发送到MQTT。

最后，在Controller中调用这个Service即可：

@RestController
public class MyController {

    @Autowired
    private MqttRabbitMQService mqttRabbitMQService;

    @GetMapping("/send")
    public String sendMessage() {
        mqttRabbitMQService.sendMqttMessageToRabbitMQ("test/topic", "Hello RabbitMQ");
        return "Message sent successfully!";
    }
}

这样就可以使用MQTT发送消息到RabbitMQ了。