SpringBoot整合MQTT（EMQ）设备上下线告警

1、下载EMQ安装包，配置EMQ环境

 下载 EMQX

本文以Windows为例 如图，选择对应的系统和版本

2、解压 cmd进入bin文件夹

输入 emqx start 启动服务，打卡浏览器输入本地ip:18083

 进入登录页面 默认用户名密码 admin/public

 至此MQTT服务已启动成功。

3、搭建SpringBoot项目

application.yml配文件：

#MQTT Config
  mqtt:
  #MQTT-服务器连接地址，如果有多个，用逗号隔开，如：tcp://127.0.0.1:61613，tcp://192.168.2.133:61613
    host: tcp://127.0.0.1:1883
    #MQTT-连接服务器默认客户端ID
    clientid: mqtt_id
    #MQTT-用户名
    username: admin
    #MQTT-密码
    password: admin
    #MQTT-默认的消息推送主题，实际可在调用接口时指定
    topic: test
    #连接超时
    timeout: 1000
    #设置会话心跳时间
    keepalive: 100

pom.xml

   org.springframework.integration
   spring-integration-stream


   org.springframework.integration
   spring-integration-mqtt


   org.springframework.boot
   spring-boot-starter-integration

   
    org.projectlombok   
    lombok   
    1.18.4

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.stereotype.Component;

@Component
@Configuration
@ConfigurationProperties(MqttConfiguration.PREFIX)
public class MqttConfiguration {

    @Autowired
    private MqttPushClient mqttPushClient;


    public static final  String PREFIX="mqtt";
    private String host;
    private String clientid;
    private String username;
    private String password;
    private String topic;
    private int timeout;
    private int keepalive;

    @Bean
    public MqttPushClient getMqttPushClient() {
        mqttPushClient.connect(host, clientid, username, password, timeout,keepalive);
        // 以/#结尾表示订阅所有以test开头的主题
        mqttPushClient.subscribe("test/#", 0);
        return mqttPushClient;
    }

    public String getHost() {
        return host;
    }

    public void setHost(String host) {
        this.host = host;
    }

    public String getClientid() {
        return clientid;
    }

    public void setClientid(String clientid) {
        this.clientid = clientid;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getTopic() {
        return topic;
    }

    public void setTopic(String topic) {
        this.topic = topic;
    }

    public int getTimeout() {
        return timeout;
    }

    public void setTimeout(int timeout) {
        this.timeout = timeout;
    }

    public int getKeepalive() {
        return keepalive;
    }

    public void setKeepalive(int keepalive) {
        this.keepalive = keepalive;
    }
}

消费者监听

import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken;
import org.eclipse.paho.client.mqttv3.MqttCallback;
import org.eclipse.paho.client.mqttv3.MqttClient;
import org.eclipse.paho.client.mqttv3.MqttMessage;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

/**
 * @Classname PushCallback
 * @Description 消费监听类
 */
@Component
public class PushCallback implements MqttCallback {
    @Autowired
    private MqttConfiguration mqttConfiguration;

    private static MqttClient client;

    @Override
    public void connectionLost(Throwable throwable) {if (client == null || !client.isConnected()) {
            System.out.println("连接断开，正在重连....");
            mqttConfiguration.getMqttPushClient();
        }
    }

    @Override
    public void messageArrived(String topic, MqttMessage message) throws Exception {
        
        System.out.println("接收消息主题 : " + topic);
        System.out.println("接收消息Qos : " + message.getQos());
        System.out.println("接收消息内容 : " + new String(message.getPayload()));
    }

    @Override
    public void deliveryComplete(IMqttDeliveryToken token) {
        System.out.println("deliveryComplete---------" + token.isComplete());
    }
}

重点来了，如何确定设备上下线呢？

想了好几个方案：

①：遗嘱机制

②：主题设计

③：EMQX 系统主题 ，需要修改服务配置文件

④：EMQX .Hook插件 桥接到网关服务

⑤：EMQ商业版 EMQX Enterprise

⑥：获取连到服务器的设备信息，通过状态来判断，缺点无法实时刷新状态且频繁调用接口对服务器压力大

最终选择 ③：EMQX 系统主题 ，需要修改服务配置文件

emqx\etc\acl.config

添加  {allow, all, subscribe, ["$SYS/brokers/+/clients/#"]}.

 重启服务或者重新加载  

$ ./bin/emqx_ctl acl reload

模拟设备上线：

 模拟设备下线：

 

完。