vue项目mqtt的封装与使用

1.下载安装mqtt依赖

npm install [email protected]

2.封装mqttHandler.js工具文件

import mqtt from "mqtt";
import Vue from 'vue'
var vm = new Vue();
class mqttHandle {
    constructor(subscribe) {
        this.connect = {
            host: vm.mqttHost,
            port: vm.mqttPort,
            endpoint: "/mqtt",
            clean: true, // 保留会话
            cleanSession: true,
            connectTimeout: 7000, // 超时时间
            reconnectPeriod: 7000, // 重连时间间隔
            // 认证信息
            clientId: Number(new Date()).toString(),
            username: "emqx_t",
            password: "emqx_t",
        }
        this.subscription = {
            topic: subscribe,  //需要传入数组的包含订阅的名称
            qos: 2,
        }
        this.mqttClient = null;
    }
    /**
     * 创建链接
     * @returns client
     */
    createConnect() {
        //配置链接
        const { host, port, endpoint, ...options } = this.connect;
        const connectUrl = `ws://${this.connect.host}:${this.connect.port}${this.connect.endpoint}`;
        try {
            this._client = mqtt.connect(connectUrl, options);

        } catch (error) {
            console.log("mqtt.connect error", error);
        }
        this._client.on("connect", () => {
            console.log("Connection succeeded!");
        });
        this._client.on('reconnect', (error) => {
            console.log('正在重连', error)
        })
        this._client.on("error", (error) => {
            console.log("Connection failed", error);
        });

        //配置topic
        const { topic, qos } = this.subscription;
        this._client.subscribe(topic, { qos: qos }, (error, res) => {
            if (error) {
                console.log("Subscribe to topics error", error);
                return;
            }
            this.subscribeSuccess = true;
            // console.log("Subscribe to topics res", res[0].qos, res[0].topic);
        });
        this.mqttClient = this._client;
        return this.mqttClient;
    }
}

export default mqttHandle;

3.在要订阅mqtt的页面引入mqttHandler.js

// mqtt
import mqttHandle from "../../../utils/mqttHandle";

4.声明订阅mqtt的时候要用到的变量

var mqtt; //mqtt 处理对象（全局变量）
var client;
var topicSends; //订阅的topic 例如：["Time1", "EngineMain1", "Console1", "Location1"]

// 在data中声明接收mqtt返回数据的变量
data(){
   return{
      receiveNews: "",
   }
} 

5.需要订阅mqtt的时候调用订阅mqtt的方法，一般都是进页面就触发，所以一般都写在mounted（）方法里。

mounted(){
   this.createMqtt();
}

methods:{
   /** 创建mqtt */
    createMqtt() {
      //创建链接，接收数据
      mqtt = new mqttHandle(topicSends);
      client = mqtt.createConnect();
      client.on("message", (topic, message) => {
        //数据分类
        try {
          this.receiveNews = this.receiveNews.concat(message);
          this.realInfo(topic, this.receiveNews);
        } catch (error) {}
      });
    },
}

6.停止订阅mqtt的时候调用以下方法

//停止订阅mqtt
    disConnect() {
      if (client != null) {
        client.unsubscribe(topicSends);
        client = null;
      }
    },

7.同时订阅多个topic时，可以调用以下方法

/** 实时数据分类 */
    realInfo(topic, resInfo) {
      switch (topic) {
        // 接收时间
        case "Time1":
        case "Time2":
        case "Time3":
          try {
            this.currentTime = resInfo;
          } catch (error) {}
          break;
        // 树结构
        case "EngineMain1":
        case "EngineMain2":
        case "EngineMain3":
          break;
        // 控制台输出
        case "Console1":
        case "Console":
        case "Console2":
        case "Console3":
          try {
            let arr = JSON.parse(resInfo);
            this.$refs.rightTabRef.updateInfo(arr);
          } catch (error) {}
          break;
        // 模型
        case "Location1":
        case "Location2":
        case "Location3":
          try {
            this.modelList = JSON.parse(resInfo);
            this.modelList.forEach(item => {
              // 模型节点
              if (item.entityType != 16) {
                if (this.$refs.cesiumRef.loadModel)
                  this.$refs.cesiumRef.loadModel(item, false);
              } else {
                // 信号节点
                this.checkedModelList.forEach(item1 => {
                  // 选中的信号节点
                  if (item1.ID == item.id) {
                    // x轴数据,最多存放20条数据
                    if (this.xData.length > 20) {
                      this.xData.splice(0, 1);
                    }
                    this.xData.push(item.tagTwo);
                    let findindex = this.titleList.findIndex(
                      m => m == item1.label
                    );
                    if (findindex == -1) {
                      this.titleList.push(item1.label);
                      let ydata = {
                        name: item1.label,
                        type: "line",
                        stack: "Total",
                        data: [item.tagOne]
                      };
                      this.yData.push(ydata);
                    } else {
                      this.yData
                        .filter(s => s.name == item1.label)[0]
                        .data.push(item.tagOne);
                      let data = this.yData.filter(
                        s => s.name == item1.label
                      )[0].data;
                      if (data.length > 260) {
                        this.yData
                          .filter(s => s.name == item1.label)[0]
                          .data.splice(0, 1);
                      }
                    }
                  }
                });
              }
            });
            this.initEcharts();
          } catch (error) {}
          break;
      }
      this.receiveNews = "";
    },