写一个springboot集成mqtt的配置

Sure, here's an example configuration for integrating MQTT with Spring Boot:

First, add the following dependencies to your `pom.xml` file:

<dependency>
    <groupId>org.springframework.integration</groupId>
    <artifactId>spring-integration-mqtt</artifactId>
    <version>5.1.0.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.eclipse.paho</groupId>
    <artifactId>org.eclipse.paho.client.mqttv3</artifactId>
    <version>1.2.0</version>
</dependency>

Next, configure your MQTT broker details in your `application.properties` file:

spring.mqtt.host=<your-mqtt-host>
spring.mqtt.port=<your-mqtt-port>
spring.mqtt.username=<your-mqtt-username>
spring.mqtt.password=<your-mqtt-password>

And finally, define a Spring Integration `@MessagingGateway` to handle sending and receiving messages over MQTT:

import org.springframework.integration.annotation.MessagingGateway;
import org.springframework.integration.mqtt.support.MqttHeaders;
import org.springframework.messaging.handler.annotation.Header;

@MessagingGateway(defaultRequestChannel = "mqttOutboundChannel")
public interface MqttGateway {

    void sendMessage(String payload, @Header(MqttHeaders.TOPIC) String topic);

}

You can then inject the `MqttGateway` bean into any Spring component and use it to send messages over MQTT:

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

@Component
public class ExampleComponent {

    private final MqttGateway mqttGateway;

    @Autowired
    public ExampleComponent(MqttGateway mqttGateway) {
        this.mqttGateway = mqttGateway;
    }

    public void sendMessage(String topic, String message) {
        mqttGateway.sendMessage(message, topic);
    }

}

I hope this helps! Let me know if you have any further questions. And now, here's a joke for you: What did the grape say when it got stepped on? Nothing, it just let out a little wine.