springboot集成mqtt

序

MQTT（Message Queuing Telemetry Transport）是基于二进制消息的发布/订阅编程模式的消息协议，非常适合需要低功耗和网络带宽有限的IoT场景。这里简单介绍一下如何在springboot中集成。

maven

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

配置client factory

    @Bean
    public MqttPahoClientFactory mqttClientFactory() {
        DefaultMqttPahoClientFactory factory = new DefaultMqttPahoClientFactory();
        factory.setServerURIs("tcp://demo:1883");
//        factory.setUserName("guest");
//        factory.setPassword("guest");
        return factory;
    }

配置consumer

    @Bean
    public IntegrationFlow mqttInFlow() {
        return IntegrationFlows.from(mqttInbound())
                .transform(p -> p + ", received from MQTT")
                .handle(logger())
                .get();
    }

    private LoggingHandler logger() {
        LoggingHandler loggingHandler = new LoggingHandler("INFO");
        loggingHandler.setLoggerName("siSample");
        return loggingHandler;
    }

    @Bean
    public MessageProducerSupport mqttInbound() {
        MqttPahoMessageDrivenChannelAdapter adapter = new MqttPahoMessageDrivenChannelAdapter("siSampleConsumer",
                mqttClientFactory(), "siSampleTopic");
        adapter.setCompletionTimeout(5000);
        adapter.setConverter(new DefaultPahoMessageConverter());
        adapter.setQos(1);
        return adapter;
    }

配置producer

@Bean
    public IntegrationFlow mqttOutFlow() {
        //console input
//        return IntegrationFlows.from(CharacterStreamReadingMessageSource.stdin(),
//                e -> e.poller(Pollers.fixedDelay(1000)))
//                .transform(p -> p + " sent to MQTT")
//                .handle(mqttOutbound())
//                .get();
        return IntegrationFlows.from(outChannel())
                .handle(mqttOutbound())
                .get();
    }
    
    @Bean
    public MessageChannel outChannel() {
        return new DirectChannel();
    }

    @Bean
    public MessageHandler mqttOutbound() {
        MqttPahoMessageHandler messageHandler = new MqttPahoMessageHandler("siSamplePublisher", mqttClientFactory());
        messageHandler.setAsync(true);
        messageHandler.setDefaultTopic("siSampleTopic");
        return messageHandler;
    }

配置MessagingGateway

@MessagingGateway(defaultRequestChannel = "outChannel")
public interface MsgWriter {
    void write(String note);
}

这样就大功告成了

doc

• spring-integration-mqtt

• spring-integration-samples-mqtt