//封裝一個(gè)類（可直接cv）
class createds {
  //創(chuàng)建公共變量
  static url; //mqtt地址
  static oldSubscribe; //取消訂閱準(zhǔn)備
  static subscribe; //訂閱地址
  static client; //mqtt公共變量
  //接受床底來的數(shù)據(jù)
  constructor(subscribe) {
    console.log(subscribe, "訂閱地址");
    //獲取傳遞來的訂閱地址
    this.subscribe = subscribe;
    this.url = "ws://127.0.0.1:8083/mqtt";
  }
 
  //初始化mqtt
  init() {
    const options = {
      clean: true, // true: 清除會(huì)話, false: 保留會(huì)話
      connectTimeout: 4000, // 超時(shí)時(shí)間
    };
    this.client = mqtt.connect(this.url, options);
    this.client.on("error", (error) => {});
    this.client.on("reconnect", (error) => {});
  }
  //取消訂閱
  unsubscribes() {
    this.client.unsubscribe(this.subscribe, (error) => {
      if (!error) {
        console.log(this.subscribe, "取消訂閱成功");
      } else {
        console.log(this.subscribe, "取消訂閱失敗");
      }
    });
  }
  //結(jié)束鏈接
  over() {
    this.client.end();
  }
  //鏈接
  link() {
    this.client.on("connect", (e) => {
      this.client.subscribe(this.subscribe, (error) => {
        //在js代碼中最簡(jiǎn)單的拋出異常方法
        if (!error) {
          console.log("訂閱成功");
        } else {
          console.log("訂閱失敗");
        }
      });
    });
  }
  //收到的消息
  get() {
    this.client.on("message", (topic, message) => {
      console.log("收到消息：", message.toString());
    });
  }
  //結(jié)束鏈接
  over() {
    this.client.end();
  }
}
export default createds;

使用

//引入封裝的類
import createds from "@/utils/mqtt.js";
 
const PublicMqtt = ref(null);
const startMqtt = (val) => {
  //val = 訂閱地址
  //設(shè)置訂閱地址
  PublicMqtt.value = new createds(val);
  //初始化mqtt
  PublicMqtt.value.init();
  //鏈接mqtt
  PublicMqtt.value.link();
  getMessage();
};
//獲取訂閱數(shù)據(jù)
const getMessage = () => {
  PublicMqtt.value.client.on("message", (topic, message) => {
    let str = JSON.parse(message.toString());
    console.log(str,'返回的數(shù)據(jù)')
  });
};
//取消MQTT訂閱
const unsubscribe = () => {
  //如果頁(yè)面并沒有初始化MQTT，無需取消訂閱
  if (PublicMqtt.value) {
    PublicMqtt.unsubscribes();
  }
};
onUnmounted(() => {
  //頁(yè)面銷毀結(jié)束訂閱
  if (PublicMqtt.value) {
    PublicMqtt.value.unsubscribes();
    PublicMqtt.value.over();
  }
});
 
// vue3使用npm下載mqtt依賴可能跑不起來，可以把他的js文件下載下來放在本地

下面再看下vue3調(diào)用mqtt

npm install mqtt -S

utils下面新建mqtt頁(yè)面

import { MqttClient, OnMessageCallback } from 'mqtt';
import mqtt from 'mqtt';
 
class MQTT {
  url: string; // mqtt地址
  topic: string; //訂閱地址
  client!: MqttClient;
  constructor(topic: string) {
    this.topic = topic;
    // 雖然是mqtt但是在客戶端這里必須采用websock的鏈接方式
    this.url = 'ws://www.liufengtec.com:8083/mqtt';
  }
 
  //初始化mqtt
  init() {
    const options = {
        host: 'www.liufengtec.com',
        port: 8083,
        endpoint: '/mqtt',
        clean: true, // 保留會(huì)話
        connectTimeout: 4000, // 超時(shí)時(shí)間
        reconnectPeriod: 4000, // 重連時(shí)間間隔
        // 認(rèn)證信息
        clientId: 'mqttjs_3be2c321',
        username: 'admin',
        password: '3Ha86294',
    };
    this.client = mqtt.connect(this.url, options);
    this.client.on('error', (error: any) => {
      console.log(error);
    });
    this.client.on('reconnect', (error: Error) => {
      console.log(error);
    });
  }
  //取消訂閱
  unsubscribes() {
    this.client.unsubscribe(this.topic, (error: Error) => {
      if (!error) {
        console.log(this.topic, '取消訂閱成功');
      } else {
        console.log(this.topic, '取消訂閱失敗');
      }
    });
  }
  //連接
  link() {
    this.client.on('connect', () => {
      this.client.subscribe(this.topic, (error: any) => {
        if (!error) {
          console.log('訂閱成功');
        } else {
          console.log('訂閱失敗');
        }
      });
    });
  }
  //收到的消息
  get(callback: OnMessageCallback) {
    this.client.on('message', callback);
    // console.log(callback,"1010")
  }
  //結(jié)束鏈接
  over() {
    this.client.end();
  }
}
export default MQTT;

utils下面新建usemqtt.ts頁(yè)面

import MQTT from '@/utils/mqtt';
import { OnMessageCallback } from 'mqtt';
import { ref } from "vue";
 
export default function useMqtt() {
  const PublicMqtt = ref<MQTT | null>(null);
 
  const startMqtt = (val: string, callback: OnMessageCallback) => {
    //設(shè)置訂閱地址
    PublicMqtt.value = new MQTT(val);
    //初始化mqtt
    PublicMqtt.value.init();
    //鏈接mqtt
    PublicMqtt.value.link();
    getMessage(callback);
  };
  const getMessage = (callback: OnMessageCallback) => {
    //   console.log(callback,"18")
    // PublicMqtt.value?.client.on('message', callback);
    // @ts-ignore //忽略提示
    PublicMqtt.value?.get(callback);
  };
//   onUnmounted(() => {
//     //頁(yè)面銷毀結(jié)束訂閱
//     if (PublicMqtt.value) {
//       PublicMqtt.value.unsubscribes();
//       PublicMqtt.value.over();
//     }
//   });
 
  return {
    startMqtt,
  };
}

使用頁(yè)面調(diào)用

import useMqtt from '@/utils/usemqtt';
const { startMqtt } = useMqtt();
startMqtt(deviceSnsss, (topic, message) => {
console.log(message)
}

或者

<template>
  <div id="app">
    <div class="head">
      <p>天潤(rùn)商城后臺(tái)管理系統(tǒng)</p>
    </div>
    <div class="login">
      <table border="0" cellspacing="20">
        <tr>
          <td>用戶名：</td>
          <td>
            <el-input
              prefix-icon="iconfont icon-xingmingyonghumingnicheng"
              placeholder="請(qǐng)輸入賬號(hào)"
              v-model="account"
              clearable
            ></el-input>
          </td>
        </tr>
 
        <tr>
          <td>密碼：</td>
          <td>
            <el-input
              prefix-icon="iconfont icon-mima"
              placeholder="請(qǐng)輸入密碼"
              v-model="password"
              show-password
            ></el-input>
          </td>
        </tr>
        <tr>
          <td colspan="2" style="text-align: center; padding-top: 50px">
            <el-button type="danger" style="width: 60%" @click="login"
              >登錄</el-button
            >
          </td>
        </tr>
      </table>
    </div>
  </div>
</template>
 
<script>
  import mqtt from 'mqtt'
  
  export default {
    data() {
      return {
        account:"12",
        password:"12",
        connection: {
          host: 'www.liufengtec.com',
          port: 8084,
          endpoint: '/mqtt',
          clean: true, // 保留會(huì)話
          connectTimeout: 4000, // 超時(shí)時(shí)間
          reconnectPeriod: 4000, // 重連時(shí)間間隔
          // 認(rèn)證信息
          clientId: 'mqttjs_3be2c321',
          username: 'admin',
          password: '3Ha86294',
        },
        subscription: {
          topic: 'topic/mqttx',
          qos: 0,
        },
        publish: {
          topic: 'topic/browser',
          qos: 0,
          payload: '{ "msg": "Hello, I am browser." }',
        },
        receiveNews: '',
        qosList: [
          { label: 0, value: 0 },
          { label: 1, value: 1 },
          { label: 2, value: 2 },
        ],
        client: {
          connected: false,
        },
        subscribeSuccess: false,
      }
    },
  
    methods: {
      login(){
         this.createConnection();
      },
      // 創(chuàng)建連接
      createConnection() {
        let that=this;
        // 連接字符串, 通過協(xié)議指定使用的連接方式
        // ws 未加密 WebSocket 連接
        // wss 加密 WebSocket 連接
        // mqtt 未加密 TCP 連接
        // mqtts 加密 TCP 連接
        // wxs 微信小程序連接
        // alis 支付寶小程序連接
        const { host, port, endpoint, ...options } = this.connection
        const connectUrl = `ws://www.liufengtec.com:8083/mqtt`
        try {
          this.client = mqtt.connect(connectUrl)
        } catch (error) {
          console.log('mqtt.connect error', error)
        }
        this.client.on('connect', () => {
          console.log('Connection succeeded!')
          that.subscribe();
          
        })
        this.client.on('error', error => {
          console.log('Connection failed', error)
        })
        this.client.on('message', (topic, message) => {
          this.receiveNews = this.receiveNews.concat(message)
          console.log(`Received message ${message} from topic ${topic}`)
        })
      },
      //訂閱
   subscribe() {
    var topic = "system";
    var qos = 0;
    //logMessage("INFO", "Subscribing to: [Topic: ", topic, ", QoS: ", qos, "]");
    this.client.subscribe(topic, { qos: Number(qos) });
   },
   // called when a message arrives
    message() {
      var topic = "system";
   this.client.on("message", (topic, message) => {
      console.log(message)
    });
  }
    }
  }
  </script>
 
<style lang="less" scoped>
.head {
  height: 150px;
  width: 100vw;
  background-image: url(../assets/banner.jpg);
  background-repeat: no-repeat;
  background-size: cover;
  p {
    font-size: 30px;
    color: white;
    line-height: 150px;
    margin-left: 50px;
  }
}
.bg-purple {
  background: #d3dce6;
}
 
.grid-content {
  border-radius: 4px;
  min-height: 36px;
}
.login {
  display: flex;
  flex-direction: column;
  justify-content: center;
  width: 400px;
  margin: 0px auto;
  border: 2px #f3f3f3 solid;
  padding: 100px;
}
</style>

不封裝直接使用。ws和wss不一樣