emqx 从客户端取数

说明

这里使用的事org.eclipse.paho.client.mqttv3包里的mqtt相关类
原因：灵活度高

有两个客户端，一个用来发布消息，另一个用来订阅处理消息

provider客户端

依赖

<?xml version="1.0" encoding="UTF-8"?>
<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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.6.7</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>mqtt_provider</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>mqtt_provider</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <!--mqtt相关依赖-->
        <dependency>
            <groupId>org.eclipse.paho</groupId>
            <artifactId>org.eclipse.paho.client.mqttv3</artifactId>
            <version>1.2.5</version>
        </dependency>
        <!--  mqtt end -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.20</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>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>2.6.7</version>
            </plugin>
        </plugins>
    </build>
</project>

配置文件

spring:
  application:
    name: provider
  #MQTT配置信息
  mqtt:
    #MQTT服务端地址，端口默认为11883，如果有多个，用逗号隔开
    url: tcp://10.18.6.229:1883
    #用户名
    username: admin
    #密码
    password: public
    #客户端id（不能重复）
    client:
      id: provider-id
    #MQTT默认的消息推送主题，实际可在调用接口时指定
    default:
      topic: doTest
server:
  port: 8080

MqttProviderConfig配置类

package com.example.mqtt_provider.config;

import lombok.extern.slf4j.Slf4j;
import org.eclipse.paho.client.mqttv3.*;
import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;

import javax.annotation.PostConstruct;

/**
 * @projectName mqtt
 * @class: MqttProviderConfig
 * @description: TODO
 * @date 2022/4/26
 */
@Slf4j
@Configuration
public class MqttProviderConfig {
    @Value("${spring.mqtt.username}")
    private String username;

    @Value("${spring.mqtt.password}")
    private String password;

    @Value("${spring.mqtt.url}")
    private String hostUrl;

    @Value("${spring.mqtt.client.id}")
    private String clientId;

    @Value("${spring.mqtt.default.topic}")
    private String defaultTopic;

    /**
     * 客户端对象
     */
    private MqttClient client;

    /**
     * 在bean初始化后连接到服务器
     */
    @PostConstruct
    public void init(){
        connect();
    }

    /**
     * 客户端连接服务端
     */
    public void connect(){
        try{
            //创建MQTT客户端对象
            client = new MqttClient(hostUrl,clientId,new MemoryPersistence());
            //连接设置
            MqttConnectOptions options = new MqttConnectOptions();
            //是否清空session，设置false表示服务器会保留客户端的连接记录（订阅主题，qos）,客户端重连之后能获取到服务器在客户端断开连接期间推送的消息
            //设置为true表示每次连接服务器都是以新的身份
            options.setCleanSession(true);
            //设置连接用户名
            options.setUserName(username);
            //设置连接密码
            options.setPassword(password.toCharArray());
            //设置超时时间，单位为秒
            options.setConnectionTimeout(100);
            //设置心跳时间 单位为秒，表示服务器每隔 1.5*20秒的时间向客户端发送心跳判断客户端是否在线
            options.setKeepAliveInterval(20);
            //设置遗嘱消息的话题，若客户端和服务器之间的连接意外断开，服务器将发布客户端的遗嘱信息
            options.setWill("willTopic",(clientId + "与服务器断开连接").getBytes(),0,false);
            //设置回调
            client.setCallback(new MqttProviderCallBack());
            client.connect(options);
        } catch(MqttException e){
            e.printStackTrace();
        }

    }
    public void publish(int qos,boolean retained,String topic,String message){
        MqttMessage mqttMessage = new MqttMessage();
        mqttMessage.setQos(qos);
        mqttMessage.setRetained(retained);
        mqttMessage.setPayload(message.getBytes());
        //主题的目的地，用于发布/订阅信息
        MqttTopic mqttTopic = client.getTopic(topic);
        //提供一种机制来跟踪消息的传递进度
        //用于在以非阻塞方式（在后台运行）执行发布是跟踪消息的传递进度
        MqttDeliveryToken token;
        try {
            //将指定消息发布到主题，但不等待消息传递完成，返回的token可用于跟踪消息的传递状态
            //一旦此方法干净地返回，消息就已被客户端接受发布，当连接可用，将在后台完成消息传递。
            token = mqttTopic.publish(mqttMessage);
            token.waitForCompletion();
        } catch (MqttException e) {
            e.printStackTrace();
        }
    }
}

MqttProviderCallBack回调类

package com.example.mqtt_provider.config;

import org.eclipse.paho.client.mqttv3.IMqttAsyncClient;
import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken;
import org.eclipse.paho.client.mqttv3.MqttCallback;
import org.eclipse.paho.client.mqttv3.MqttMessage;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;

/**
 * @projectName mqtt
 * @class: MqttProviderCallBack
 * @description: TODO
 * @date 2022/4/26
 */
@Configuration
public class MqttProviderCallBack implements MqttCallback {
    @Value("${spring.mqtt.client.id}")
    private String clientId;
    /**
     * 与服务器断开的回调
     */
    @Override
    public void connectionLost(Throwable cause) {
        System.out.println(clientId+"与服务器断开连接");
    }

    /**
     * 消息到达的回调
     */
    @Override
    public void messageArrived(String topic, MqttMessage message) throws Exception {
        System.out.println("message arrived");
    }

    /**
     * 消息发布成功的回调
     */
    @Override
    public void deliveryComplete(IMqttDeliveryToken token) {
        IMqttAsyncClient client = token.getClient();
        System.out.println(client.getClientId()+"发布消息成功！");
    }
}

发送消息控制类

package com.example.mqtt_provider.controller;

import com.example.mqtt_provider.config.MqttProviderConfig;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;

/**
 * @projectName mqtt
 * @class: SendController
 * @description: TODO
 * @date 2022/4/26
 */
@RestController
public class SendController {
    @Resource
    private MqttProviderConfig providerClient;

    @RequestMapping("/sendMessage")
    public String sendMessage(int qos,boolean retained,String topic,String message){
        try {
            providerClient.publish(qos, retained, topic, message);
            return "发送成功";
        } catch (Exception e) {
            e.printStackTrace();
            return "发送失败";
        }
    }
}

Consumer客户端

依赖

<?xml version="1.0" encoding="UTF-8"?>
<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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.6.7</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>mqtt_consumer</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>mqtt_consumer</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <!--mqtt相关依赖-->
        <dependency>
            <groupId>org.eclipse.paho</groupId>
            <artifactId>org.eclipse.paho.client.mqttv3</artifactId>
            <version>1.2.5</version>
        </dependency>
        <!--  mqtt end -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.20</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>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>2.6.7</version>
            </plugin>
        </plugins>
    </build>
</project>

配置文件

spring:
  application:
    name: consumer
  #MQTT配置信息
  mqtt:
    #MQTT服务端地址，端口默认为11883，如果有多个，用逗号隔开
    url: tcp://10.18.6.229:1883
    #用户名
    username: admin
    #密码
    password: public
    #客户端id（不能重复）
    client:
      id: consumer-id
    #MQTT默认的消息推送主题，实际可在调用接口时指定
    default:
      topic: doTest
server:
  port: 8085

MqttConsumerConfig配置类

package com.example.mqtt_consumer.config;

import org.eclipse.paho.client.mqttv3.MqttClient;
import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
import org.eclipse.paho.client.mqttv3.MqttException;
import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;

import javax.annotation.PostConstruct;

/**
 * @projectName mqtt
 * @class: MqttConsumerConfig
 * @description: TODO
 * @date 2022/4/26
 */
@Configuration
public class MqttConsumerConfig {
    @Value("${spring.mqtt.username}")
    private String username;

    @Value("${spring.mqtt.password}")
    private String password;

    @Value("${spring.mqtt.url}")
    private String hostUrl;

    @Value("${spring.mqtt.client.id}")
    private String clientId;

    @Value("${spring.mqtt.default.topic}")
    private String defaultTopic;

    /**
     * 客户端对象
     */
    private MqttClient client;

    /**
     * 在bean初始化后连接到服务器
     */
    @PostConstruct
    public void init(){
        connect();
    }

    /**
     * 客户端连接服务端
     */
    public void connect(){
        try {
            //创建MQTT客户端对象
            client = new MqttClient(hostUrl,clientId,new MemoryPersistence());
            //连接设置
            MqttConnectOptions options = new MqttConnectOptions();
            //是否清空session，设置为false表示服务器会保留客户端的连接记录，客户端重连之后能获取到服务器在客户端断开连接期间推送的消息
            //设置为true表示每次连接到服务端都是以新的身份
            options.setCleanSession(true);
            //设置连接用户名
            options.setUserName(username);
            //设置连接密码
            options.setPassword(password.toCharArray());
            //设置超时时间，单位为秒
            options.setConnectionTimeout(100);
            //设置心跳时间 单位为秒，表示服务器每隔1.5*20秒的时间向客户端发送心跳判断客户端是否在线
            options.setKeepAliveInterval(20);
            //设置遗嘱消息的话题，若客户端和服务器之间的连接意外断开，服务器将发布客户端的遗嘱信息
            options.setWill("willTopic",(clientId + "与服务器断开连接").getBytes(),0,false);
            //设置回调
            client.setCallback(new MqttConsumerCallBack());
            client.connect(options);
            //订阅主题
            //消息等级，和主题数组一一对应，服务端将按照指定等级给订阅了主题的客户端推送消息
            int[] qos = {1,1,1};
            //主题
            String[] topics = {"topic1","topic2","doTest"};
            //订阅主题
            client.subscribe(topics,qos);
        } catch (MqttException e) {
            e.printStackTrace();
        }
    }

    /**
     * 断开连接
     */
    public void disConnect(){
        try {
            client.disconnect();
        } catch (MqttException e) {
            e.printStackTrace();
        }
    }


    /**
     * 订阅主题
     */
    public void subscribe(String topic,int qos){
        try {
            client.subscribe(topic,qos);
        } catch (MqttException e) {
            e.printStackTrace();
        }
    }
}

MqttConsumerCallBack回调类

package com.example.mqtt_consumer.config;

import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken;
import org.eclipse.paho.client.mqttv3.MqttCallback;
import org.eclipse.paho.client.mqttv3.MqttMessage;

/**
 * @projectName mqtt
 * @class: MqttConsumerCallBack
 * @description: TODO
 * @date 2022/4/26
 */
public class MqttConsumerCallBack implements MqttCallback {
    /**
     * 客户端断开连接的回调
     */
    @Override
    public void connectionLost(Throwable throwable) {
        System.out.println("与服务器断开连接，可重连");
    }

    /**
     * 消息到达的回调
     */
    @Override
    public void messageArrived(String topic, MqttMessage message) throws Exception {
        System.out.println(String.format("接收消息主题 : %s",topic));
        System.out.println(String.format("接收消息Qos : %d",message.getQos()));
        System.out.println(String.format("接收消息内容 : %s",new String(message.getPayload())));
        System.out.println(String.format("接收消息retained : %b",message.isRetained()));
    }

    /**
     * 消息发布成功的回调
     */
    @Override
    public void deliveryComplete(IMqttDeliveryToken iMqttDeliveryToken) {
    }
}

客户端测试连接和断开控制类

package com.example.mqtt_consumer.controller;

import com.example.mqtt_consumer.config.MqttConsumerConfig;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;

/**
 * @projectName mqtt
 * @class: TestController
 * @description: TODO
 * @date 2022/4/26
 */
@RestController
public class TestController {
    @Resource
    private MqttConsumerConfig client;

    @Value("${spring.mqtt.client.id}")
    private String clientId;

    @RequestMapping("/connect")
    public String connect(){
        client.connect();
        return clientId + "连接到服务器";
    }

    @RequestMapping("/disConnect")
    public String disConnect(){
        client.disConnect();
        return clientId + "与服务器断开连接";
    }
}

POSTMAN发送消息测试

Provider显示

Consumer显示

登录EMQ控制台查看

http://10.18.6.229:18083/#/ 账号/密码： admin/public
emq默认账号和密码，你也可以自己创建一个

说明：
这个就是安装emq的服务器地址在加18083端口，具体还有哪些端口，看这里

登录之后就是这个样子

查看连接的客户端

你可以名称进入具体的一个客户端查看具体详细信息

查看主题信息

查看统计信息

如果说没有启动插件，那你就在新建哪里有个启动，开启就好。

如果没有主题，创建一个发布的主题就好。上图的三个就是我自己新建的。