Spring Boot中集成MQTT详细教程

Spring Boot作为一款简化Spring开发的框架，广泛应用于微服务领域。而随着物联网技术的发展，MQTT成为了一种流行的消息传递协议。本文将简单介绍如何在Spring Boot中集成MQTT。

在pom.xml文件中添加MQTT依赖 org.springframework.integration spring-integration-mqtt 5.2.3.RELEASE 在application.properties文件中配置MQTT连接信息 spring.mqtt.username=yourusername spring.mqtt.password=yourpassword spring.mqtt.url=tcp://yourmqttBrokerUrl:yourmqttPort 创建一个MQTT的配置类 @Configuration @EnableConfigurationProperties(MqttProperties.class) public class MqttConfig {

@Autowired
private MqttProperties properties;

@Bean
public MqttConnectOptions getMqttConnectOptions() {
    MqttConnectOptions options = new MqttConnectOptions();
    options.setUserName(properties.getUsername());
    options.setPassword(properties.getPassword().toCharArray());
    options.setServerURIs(new String[]{properties.getUrl()});
    options.setKeepAliveInterval(properties.getKeepAliveInterval());
    options.setCleanSession(true);
    return options;
}

@Bean
public MqttPahoClientFactory mqttClientFactory() {
    DefaultMqttPahoClientFactory factory = new DefaultMqttPahoClientFactory();
    factory.setConnectionOptions(getMqttConnectOptions());
    return factory;
}

@Bean
public MessageConverter messageConverter() {
    return new DefaultPahoMessageConverter();
}

@Bean
public MessageChannel mqttInputChannel() {
    return new DirectChannel();
}

@Bean
public MessageProducer inbound() {
    MqttPahoMessageDrivenChannelAdapter adapter =
            new MqttPahoMessageDrivenChannelAdapter(properties.getClientId(), mqttClientFactory(),
                    properties.getDefaultTopic().split(","));
    adapter.setCompletionTimeout(properties.getCompletionTimeout());
    adapter.setConverter(messageConverter());
    adapter.setQos(properties.getQos());
    adapter.setOutputChannel(mqttInputChannel());
    return adapter;
}

@Bean
public MessageHandler mqttOutbound() {
    MqttPahoMessageHandler messageHandler =
            new MqttPahoMessageHandler(properties.getClientId() + "Outbound", mqttClientFactory());
    messageHandler.setAsync(true);
    messageHandler.setDefaultTopic(properties.getDefaultTopic());
    return messageHandler;
}

} 配置MqttProperties类 @ConfigurationProperties(prefix = “spring.mqtt”) public class MqttProperties { private String url; private String username; private String password; private String defaultTopic; private int completionTimeout; private int qos = 1; private int keepAliveInterval = 30; private String clientId = MqttAsyncClient.generateClientId(); // getters and setters } 创建消息处理器并使用注入的MessageChannel发布消息示例： @Service public class MqttService {

private final MessageChannel mqttInputChannel;

public MqttService(@Qualifier("mqttInputChannel") MessageChannel mqttInputChannel) {
    this.mqttInputChannel = mqttInputChannel;
}

public void sendMessage(String payload) {
    Message<String> message = MessageBuilder.withPayload(payload).build();
    mqttInputChannel.send(message);
}

} 完成以上步骤后，你就可以在Spring Boot应用程序中轻松地使用MQTT。以上是简要的教程，