基于RabbitMQ的MQTT实现
1.RabbitMQ mqtt协议开启
默认情况下RabbitMQ是不开启MQTT协议的，所以需要我们手动的开启相关的插件，而RabbitMQ的MQTT协议分为两种。
-
rabbitmq_mqtt 提供与后端服务交互使用，对应端口1883
-
rabbitmq_web_mqtt 提供与前端交互使用，对应端口15675
打开cmd窗口，进入RabbitMQ的sbin目录
开启rabbitmq_mqtt协议
rabbitmq-plugins enable rabbitmq_mqtt
开启rabbitmq_web_mqtt协议
rabbitmq-plugins enable rabbitmq_web_mqtt
重启RabbitMQ后，登录RabbitMQ管理后台
http://127.0.0.1:15672
3.mqtt相关概念：
-
Publisher（发布者）：消息的发出者，负责生产数据。发布者发送某个主题的数据给经纪人，发布者不知道订阅者。
-
Subscriber（订阅者）：消息的订阅者，订阅经纪人管理的某个或者某几个主题。
-
Broker（经纪人）：当经纪人接收到某个主题的数据时，将数据发送给这个主题的所有订阅者。
-
Topic（主题）：可以理解为消息队列中的路由，订阅者订阅了主题之后，就可以收到发送到该主题的消息。
-
Payload（负载）；可以理解为发送消息的内容。
-
QoS（消息质量）：全称 Quality of Service，即消息的发送质量，主要有 QoS 0、QoS 1、QoS 2三个等级，下面分别介绍下：
(1) QoS 0（Almost Once）：至多一次，只发送一次，会发生消息丢失或重复；
(2) QoS 1（Atleast Once）：至少一次，确保消息到达，但消息重复可能会发生；
(3) QoS 2（Exactly Once）：只有一次，确保消息只到达一次。
3.Spring整合mqtt
- 创建项目
pom.xml文件引入如下依赖
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.olive</groupId>
<artifactId>rabbitmq-mqtt-demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.7.7</version>
<relativePath />
</parent>
<properties>
<maven.compiler.target>1.8</maven.compiler.target>
<maven.compiler.source>1.8</maven.compiler.source>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.integration</groupId>
<artifactId>spring-integration-mqtt</artifactId>
</dependency>
<dependency>
<groupId>org.eclipse.paho</groupId>
<artifactId>org.eclipse.paho.client.mqttv3</artifactId>
<version>1.2.1</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
</project>
- mqtt连接配置类
package com.olive.config;
import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.integration.mqtt.core.DefaultMqttPahoClientFactory;
import org.springframework.integration.mqtt.core.MqttPahoClientFactory;
@Configuration
public class MqttConfig {
private static String servers[] = { "tcp://127.0.0.1:1883" };
private static String username = "admin";
private static String password = "admin123";
@Bean
public MqttConnectOptions getMqttConnectOptions() {
MqttConnectOptions options = new MqttConnectOptions();
// 设置是否清空session,这里如果设置为false表示服务器会保留客户端的连接记录，
// 这里设置为true表示每次连接到服务器都以新的身份连接
options.setCleanSession(true);
// 设置连接的用户名
options.setUserName(username);
// 设置连接的密码
options.setPassword(password.toCharArray());
options.setServerURIs(servers);
// 设置超时时间 单位为秒
options.setConnectionTimeout(10);
// 设置会话心跳时间 单位为秒 服务器会每隔1.5*20秒的时间向客户端发送心跳判断客户端是否在线，但这个方法并没有重连的机制
options.setKeepAliveInterval(20);
// 设置“遗嘱”消息的话题，若客户端与服务器之间的连接意外中断，服务器将发布客户端的“遗嘱”消息。
//options.setWill("willTopic", WILL_DATA, 2, false);
return options;
}
@Bean
public MqttPahoClientFactory mqttClientFactory() {
DefaultMqttPahoClientFactory factory = new DefaultMqttPahoClientFactory();
factory.setConnectionOptions(getMqttConnectOptions());
return factory;
}
}
- 消息生产者配置类
package com.olive.config;
import org.springframework.beans.factory.annotation.Autowired;
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.MqttPahoClientFactory;
import org.springframework.integration.mqtt.outbound.MqttPahoMessageHandler;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.MessageHandler;
@Configuration
public class MqttProducerConfig {
public static final String CHANNEL_NAME_OUT = "mqttOutboundChannel";
private static String clientId = "test_mqtt/producer";
private static String topic = "test_mqtt_topic";
@Autowired
MqttPahoClientFactory mqttClientFactory;
/**
* MQTT信息通道（生产者）
*/
@Bean(name = CHANNEL_NAME_OUT)
public MessageChannel mqttOutboundChannel() {
return new DirectChannel();
}
/**
* MQTT消息处理器（生产者）
*/
@Bean
@ServiceActivator(inputChannel = CHANNEL_NAME_OUT)
public MessageHandler mqttOutbound() {
MqttPahoMessageHandler messageHandler = new MqttPahoMessageHandler(clientId, mqttClientFactory);
messageHandler.setAsync(false);
messageHandler.setDefaultTopic(topic);
return messageHandler;
}
}
- 消息监听器配置类
package com.olive.config;
import org.springframework.beans.factory.annotation.Autowired;
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.MqttPahoClientFactory;
import org.springframework.integration.mqtt.inbound.MqttPahoMessageDrivenChannelAdapter;
import org.springframework.integration.mqtt.support.DefaultPahoMessageConverter;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.MessageHandler;
import org.springframework.messaging.MessagingException;
@Configuration
public class MqttListener {
public static final String CHANNEL_NAME_IN = "mqttInboundChannel";
private static String clientId = "test_mqtt/consumer";
private static String listenTopic = "test_mqtt_topic";
@Autowired
MqttPahoClientFactory mqttClientFactory;
/**
* MQTT消息通道（消费者）
*/
@Bean(name = CHANNEL_NAME_IN)
public MessageChannel mqttInboundChannel() {
return new DirectChannel();
}
/**
* MQTT消息订阅绑定（消费者）
*/
@Bean
public MessageProducer inbound() {
MqttPahoMessageDrivenChannelAdapter adapter = new MqttPahoMessageDrivenChannelAdapter(clientId,
mqttClientFactory,
listenTopic);
adapter.setCompletionTimeout(5000);
adapter.setConverter(new DefaultPahoMessageConverter());
//设置消息质量：0->至多一次；1->至少一次；2->只有一次
adapter.setQos(1);
adapter.setOutputChannel(mqttInboundChannel());
return adapter;
}
/**
* MQTT消息监听器（消费者）
* MessageHandler: org.springframework:spring-messaging
*/
@Bean
@ServiceActivator(inputChannel = CHANNEL_NAME_IN)
public MessageHandler handlerMessage() {
return message -> {
try {
MessageHeaders messageHeaders = message.getHeaders();
System.out.println("messageHeaders>>" + messageHeaders);
String string = message.getPayload().toString();
System.out.println("接收到消息：" + string);
} catch (MessagingException e) {
e.printStackTrace();
}
};
}
}
handlerMessage()方法也可以独立出来，如下
package com.olive.handler;
import org.springframework.integration.annotation.ServiceActivator;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageHandler;
import org.springframework.messaging.MessageHeaders;
import org.springframework.messaging.MessagingException;
import org.springframework.stereotype.Component;
@Component
public class CustomMessageHandler implements MessageHandler {
@ServiceActivator(inputChannel = MqttListener.CHANNEL_NAME_IN)
@Override
public void handleMessage(Message<?> message) throws MessagingException {
try {
MessageHeaders messageHeaders = message.getHeaders();
System.out.println("messageHeaders>>" + messageHeaders);
String string = message.getPayload().toString();
System.out.println("接收到消息：" + string);
} catch (MessagingException e) {
e.printStackTrace();
}
}
}
- 消息发送服务
package com.olive.service;
import org.springframework.integration.annotation.MessagingGateway;
import org.springframework.integration.mqtt.support.MqttHeaders;
import org.springframework.messaging.handler.annotation.Header;
import org.springframework.stereotype.Component;
import com.olive.config.MqttProducerConfig;
@Component
@MessagingGateway(defaultRequestChannel = MqttProducerConfig.CHANNEL_NAME_OUT)
public interface MqttSender {
/**
* 发送信息到MQTT服务器
*
* @param data 发送的文本
*/
void sendToMqtt(String data);
/**
* 发送信息到MQTT服务器
*
* @param topic 主题
* @param payload 消息主体
*/
void sendToMqtt(@Header(MqttHeaders.TOPIC) String topic, String payload);
/**
* 发送信息到MQTT服务器
*
* qos: 0 至多一次，数据可能丢失 1 至少一次，数据可能重复 2 只有一次，且仅有一次，最耗性能
*
* @param topic 主题
* @param qos 服务质量
* @param payload 消息主体
*/
void sendToMqtt(@Header(MqttHeaders.TOPIC) String topic, @Header(MqttHeaders.QOS) int qos,
String payload);
}
- 验证
访问如下接口发送数据
http://127.0.0.1:8080/mqtt?msg=mqttmessage
http://127.0.0.1:8080/mqtt2?msg=mqttmessage
package com.olive.controller;
import javax.annotation.Resource;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import com.olive.service.MqttSender;
@RestController
public class MqttController {
@Resource
private MqttSender mqttSender;
/**
* 发送MQTT消息
*/
@RequestMapping(value = "/mqtt", produces = MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity<String> sendMqtt(@RequestParam(value = "msg") String message) {
System.out.println("生产MQTT消息: " + message);
mqttSender.sendToMqtt(message);
return new ResponseEntity<>("OK", HttpStatus.OK);
}
/**
* 发送MQTT消息
*/
@RequestMapping(value = "/mqtt2", produces = MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity<String> sendMqtt2(@RequestParam(value = "msg") String message) {
System.out.println("生产MQTT消息：" + message);
mqttSender.sendToMqtt("test_mqtt_topic", message);
return new ResponseEntity<>("OK", HttpStatus.OK);
}
}
