- MQTT(Message Queuing Telemetry Transport,消息队列遥测传输协议),是一种基于发布/订阅(publish/subscribe)模式的“轻量级”通讯协议,该协议构建于TCP/IP协议上,由IBM在1999年发布。
MQTT最大优点在于,用极少的代码和有限的带宽,为连接远程设备提供实时可靠的消息服务。
作为一种低开销、低带宽占用的即时通讯协议,使其在物联网、小型设备、移动应用等方面有较广泛的应用。MQTT协议特点 - MQTT是一个基于客户端-服务器的消息发布/订阅传输协议。
- MQTT协议是轻量、简单、开放和易于实现的,这些特点使它适用范围非常广泛。在很多情况下,包括受限的环境中,如:机器与机器(M2M)通信和物联网(IoT)。
- publisher 和 subscriber 都属于 MQTT Client,之所以有发布者和订阅者这个概念,其实是一种相对的概念,就是指当前客户端是在发布消息还是在接收消息,发布和订阅的功能也可以由同一个 MQTT Client 实现。MQTT 客户端是运行 MQTT 库并通过网络连接到 MQTT 代理的任何设备(从微控制器到成熟的服务器)。例如,MQTT 客户端可以是一个非常小的、资源受限的设备,它通过无线网络进行连接并具有一个最低限度的库。基本上,任何使用 TCP/IP 协议使用 MQTT 设备的都可以称之为 MQTT Client。MQTT 协议的客户端实现非常简单直接,易于实施是 MQTT 非常适合小型设备的原因之一。MQTT 客户端库可用于多种编程语言。例如,Android、Arduino、C、C++、C#、Go、iOS、Java、JavaScript 和 .NET。
- 与 MQTT Client 对应的就是 MQTT Broker,Broker 是任何发布/订阅协议的核心,根据实现的不同,代理可以处理多达数百万连接的 MQTT Client。 Broker 负责接收所有消息,过滤消息,确定是哪个Client 订阅了每条消息,并将消息发送给对应的 Client,Broker 还负责保存会话数据,这些数据包括订阅的和错过的消息。Broker 还负责客户端的身份验证和授权。
- MQTT 协议基于 TCP/IP。客户端和代理都需要有一个 TCP/IP 协议支持。 MQTT 连接始终位于
- 服务端工具:
- mosquitto https://mosquitto.org/download/
- 客户端工具:
- MQTTX https://mqttx.app/zh#download
- 修改pom.xml ,增加相关mqtt的依赖
org.springframework.integration
spring-integration-stream
org.springframework.integration
spring-integration-mqtt
4.0.0 org.springframework.boot spring-boot-starter-parent 2.1.17.RELEASE com.huawen mqtt-demo 0.0.1 mqtt-demo Boot with MQTT Demo 1.8 org.springframework.boot spring-boot-starter org.springframework.boot spring-boot-starter-web org.springframework.boot spring-boot-starter-integration org.springframework.integration spring-integration-stream org.springframework.integration spring-integration-mqtt org.projectlombok lombok 1.18.12 org.springframework.boot spring-boot-maven-plugin
- 自定义yml配置
spring:
application:
name: MQTT-DEMO
server:
port: 8989
#mqtt properties
mqtt:
#uris 可以有多个 所以是个数组
uris:
- tcp://127.0.0.1:1883
clientId: mqtt_test1
topics:
- demo
- test
username: admin
password: 123456
timeout: 30
keepalive: 60
qos: 1
- 增加config配置读取yml文件 (使用了Lombok 需要自行添加pom依赖)
package com.huawen.mqtt.config;
import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
@Component
@ConfigurationProperties(prefix = "mqtt")
@Data
public class MqttConfiguration {
private String[] uris;
private String clientId;
private String[] topics;
private String username;
private String password;
private Integer timeout;
private Integer keepalive;
private Integer qos;
}
- 消费者配置
package com.huawen.mqtt.config;
import lombok.extern.slf4j.Slf4j;
import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.integration.annotation.ServiceActivator;
import org.springframework.integration.channel.DirectChannel;
import org.springframework.integration.core.MessageProducer;
import org.springframework.integration.mqtt.core.DefaultMqttPahoClientFactory;
import org.springframework.integration.mqtt.core.MqttPahoClientFactory;
import org.springframework.integration.mqtt.inbound.MqttPahoMessageDrivenChannelAdapter;
import org.springframework.integration.mqtt.support.DefaultPahoMessageConverter;
import org.springframework.integration.mqtt.support.MqttHeaders;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.MessageHandler;
import javax.annotation.Resource;
@Configuration
@Slf4j
public class MqttInBoundConfiguration {
@Resource
private MqttConfiguration mqttProperties;
//==================================== 消费消息==========================================//
@Bean("input")
public MessageChannel mqttInputChannel() {
//直连通道
return new DirectChannel();
}
@Bean
public MqttPahoClientFactory inClientFactory() {
//设置连接属性
DefaultMqttPahoClientFactory factory = new DefaultMqttPahoClientFactory();
MqttConnectOptions options = new MqttConnectOptions();
options.setServerURIs(mqttProperties.getUris());
options.setUserName(mqttProperties.getUsername());
options.setPassword(mqttProperties.getPassword().toCharArray());
options.setConnectionTimeout(mqttProperties.getTimeout());
options.setKeepAliveInterval(mqttProperties.getKeepalive());
// 接受离线消息 告诉代理客户端是否要建立持久会话 false为建立持久会话
options.setCleanSession(false);
//设置断开后重新连接
options.setAutomaticReconnect(true);
factory.setConnectionOptions(options);
return factory;
}
@Bean
public MessageProducer producer() {
// Paho客户端消息驱动通道适配器,主要用来订阅主题 对inboundTopics主题进行监听
//clientId 加后缀 不然会报retrying 不能重复
MqttPahoMessageDrivenChannelAdapter adapter = new MqttPahoMessageDrivenChannelAdapter(mqttProperties.getClientId()+"_customer", inClientFactory(), mqttProperties.getTopics());
adapter.setCompletionTimeout(5000);
// Paho消息转换器
DefaultPahoMessageConverter defaultPahoMessageConverter = new DefaultPahoMessageConverter();
// 按字节接收消息
// defaultPahoMessageConverter.setPayloadAsBytes(true);
adapter.setConverter(defaultPahoMessageConverter);
// 设置QoS
adapter.setQos(mqttProperties.getQos());
adapter.setOutputChannel(mqttInputChannel());
return adapter;
}
@Bean
@ServiceActivator(inputChannel = "input")
public MessageHandler handler() {
return message -> {
log.info("收到的完整消息为--->{}", message);
log.info("----------------------");
log.info("message:" + message.getPayload());
log.info("Id:" + message.getHeaders().getId());
log.info("receivedQos:" + message.getHeaders().get(MqttHeaders.RECEIVED_QOS));
String topic = (String) message.getHeaders().get(MqttHeaders.RECEIVED_TOPIC);
log.info("topic:" + topic);
log.info("----------------------");
};
}
}
- 生产者配置
package com.huawen.mqtt.config;
import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.integration.annotation.ServiceActivator;
import org.springframework.integration.channel.DirectChannel;
import org.springframework.integration.mqtt.core.DefaultMqttPahoClientFactory;
import org.springframework.integration.mqtt.core.MqttPahoClientFactory;
import org.springframework.integration.mqtt.outbound.MqttPahoMessageHandler;
import org.springframework.integration.mqtt.support.DefaultPahoMessageConverter;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.MessageHandler;
import javax.annotation.Resource;
@Configuration
public class MqttOutBoundConfiguration {
@Resource
private MqttConfiguration mqttProperties;
//==================================== 发送消息==========================================//
@Bean("out")
public MessageChannel mqttOutBoundChannel() {
//直连通道
return new DirectChannel();
}
@Bean
public MqttPahoClientFactory outClientFactory() {
DefaultMqttPahoClientFactory factory = new DefaultMqttPahoClientFactory();
String[] uris = mqttProperties.getUris();
MqttConnectOptions options = new MqttConnectOptions();
options.setServerURIs(uris);
options.setUserName(mqttProperties.getUsername());
options.setPassword(mqttProperties.getPassword().toCharArray());
options.setConnectionTimeout(mqttProperties.getTimeout());
options.setKeepAliveInterval(mqttProperties.getKeepalive());
// 接受离线消息 告诉代理客户端是否要建立持久会话 false为建立持久会话
options.setCleanSession(false);
//设置断开后重新连接
options.setAutomaticReconnect(true);
factory.setConnectionOptions(options);
return factory;
}
@Bean
@ServiceActivator(inputChannel = "out")
public MessageHandler mqttOutbound() {
//发送消息和消费消息Channel可以使用相同MqttPahoClientFactory
//clientId 加后缀 不然会报retrying 不能重复
MqttPahoMessageHandler messageHandler = new MqttPahoMessageHandler(mqttProperties.getClientId() + "_producer", outClientFactory());
//如果设置成true,即异步,发送消息时将不会阻塞。
messageHandler.setAsync(true);
//设置默认QoS
messageHandler.setDefaultQos(mqttProperties.getQos());
// Paho消息转换器
DefaultPahoMessageConverter defaultPahoMessageConverter = new DefaultPahoMessageConverter();
//发送默认按字节类型发送消息
// defaultPahoMessageConverter.setPayloadAsBytes(true);
messageHandler.setConverter(defaultPahoMessageConverter);
return messageHandler;
}
}
- 创建一个通用接口 用于发送数据
package com.huawen.mqtt.inter;
import org.springframework.integration.annotation.MessagingGateway;
import org.springframework.integration.mqtt.support.MqttHeaders;
import org.springframework.messaging.handler.annotation.Header;
@MessagingGateway(defaultRequestChannel = "out")
public interface MqttGateway {
void sendToMqtt(String payload);
void sendToMqtt(@Header(MqttHeaders.TOPIC) String topic, String payload);
void sendToMqtt(@Header(MqttHeaders.TOPIC) String topic, @Header(MqttHeaders.QOS) int qos, String payload);
void sendToMqtt(@Header(MqttHeaders.TOPIC) String topic, @Header(MqttHeaders.QOS) int qos, byte[] payload);
}
- 生产者测试controller
package com.huawen.mqtt.controller;
import com.huawen.mqtt.bean.MyMessage;
import com.huawen.mqtt.inter.MqttGateway;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
import javax.annotation.Resource;
@RestController
public class MqttPublishController {
@Resource
private MqttGateway mqttGateWay;
@PostMapping("/send")
public String send(@RequestBody MyMessage myMessage) {
// 发送消息到指定主题
mqttGateWay.sendToMqtt(myMessage.getTopic(), 1, myMessage.getContent());
return "send topic: " + myMessage.getTopic() + ", message : " + myMessage.getContent();
}
}
源码地址:https://github.com/KyrieXJL/MQTT_Demo



