在Vue中使用MQTT实现通信过程

npm install mqtt

import mqtt from 'mqtt';

class MQTTClient {
  constructor(options) {
    this.client = null;
    this.messages = [];
    this.subscribers = {};
    this.defaultOptions = {
      clientId: 'vue-client_' + Math.random().toString(16).substr(2, 8),
      clean: true,
      connectTimeout: 4000,
      //username: '账号',
      //password: '密码'
    };
    this.options = { ...this.defaultOptions, ...options };
  }

  connect(brokerUrl) {
    return new Promise((resolve, reject) => {
      try {
        this.client = mqtt.connect(brokerUrl, this.options);

        this.client.on('connect', () => {
          console.log('连接成功');
          resolve(this.client);
        });

        this.client.on('error', (err) => {
          console.error('连接失败:', err);
          reject(err);
        });

        this.client.on('message', (topic, payload) => {
          const message = {
            topic: topic,
            content: payload.toString()
          };
          this.messages.push(message);
          
          // 如果有订阅者，通知所有订阅了该主题的回调
          if (this.subscribers[topic]) {
            this.subscribers[topic].forEach(callback => callback(message));
          }
        });

        this.client.on('close', () => {
          console.log('MQTT connection closed');
        });
      } catch (err) {
        reject(err);
      }
    });
  }
// 订阅主题
  subscribe(topic, callback, qos = 0) {
    if (!this.client || this.client.connected === false) {
      // console.error('MQTT not connected');
      return;
    }

    this.client.subscribe(topic, { qos }, (err) => {
      if (!err) {
        console.log(`Subscribed to ${topic}`);
        // 存储订阅回调
        if (!this.subscribers[topic]) {
          this.subscribers[topic] = [];
        }
        this.subscribers[topic].push(callback);
      }
    });
  }
// 取消订阅指定主题的方法
  unsubscribe(topic) {
    if (!this.client || this.client.connected === false) {
      console.error('MQTT not connected');
      return;
    }

    this.client.unsubscribe(topic, (err) => {
      if (!err) {
        console.log(`Unsubscribed from ${topic}`);
        // 移除订阅回调
        if (this.subscribers[topic]) {
          delete this.subscribers[topic];
        }
      }
    });
  }
// 发送消息
  publish(topic, message, qos = 0, retain = false) {
    if (!this.client || this.client.connected === false) {
      console.error('MQTT not connected');
      return;
    }

    this.client.publish(topic, message, { qos, retain }, (err) => {
      if (err) {
        console.error('Publish error:', err);
      }
    });
  }
// 取消连接
  disconnect() {
    if (this.client) {
      this.client.end();
      this.client = null;
    }
  }

  getMessages() {
    return [...this.messages];
  }

  clearMessages() {
    this.messages = [];
  }
}

export default MQTTClient;

<template>
  <div>
    <h3>接收的 MQTT 消息：</h3>
    <ul>
      <li v-for="(msg, index) in messages" :key="index">
        {{ msg.topic }}: {{ msg.content }}
      </li>
    </ul>
    <!-- <ul>
      <li v-for="(msg, index) in top2" :key="index">
        {{ msg.topic }}: {{ msg.content }}
      </li>
    </ul> -->
    <button @click="publishMessage">发送消息</button>
  </div>
</template>

<script>
import MQTTClient from '@/util/mqtt';

export default {
  data() {
    return {
      mqttClient: null,
      messages: [],
      top2:[]
    };
  },
  mounted() {
    this.initMQTT();
  },
  methods: {
    initMQTT() {
      this.mqttClient = new MQTTClient();
      
      // 连接到 MQTT 代理
       const url="ws://"+"你的地址"+":8083/mqtt"  //例如ws://172.18.14.167:8083/mqtt
      this.mqttClient.connect(url)
        .then(() => {
          console.log('订阅成功');
          // 订阅主题
          this.mqttClient.subscribe('kpmqqt-lims-data-top1', (message) => {
            this.messages.push(message);
          });
          // this.mqttClient.subscribe('kpmqqt-lims-data-top2', (message) => {
          //   this.top2.push(message);
          // });
        })
        .catch(err => {
          console.error('MQTT connection failed:', err);
        });
    },
    publishMessage() {
      if (this.mqttClient) {
        this.mqttClient.publish('kpmqqt-lims-data-top1', 'Hello from 测试Vue2!');
        // this.mqttClient.publish('kpmqqt-lims-data-top2', 'Hello from 测试!');
      } else {
        console.error('MQTT client not initialized');
      }
    }
  },
  beforeDestroy() {
    if (this.mqttClient) {
      this.mqttClient.disconnect();
    }
  }
};
</script>

<template>
  <div>
    <h3>接收的 MQTT 消息：</h3>
    <ul>
      <li v-for="(msg, index) in messages" :key="index">
        {{ msg.topic }}: {{ msg.content }}
      </li>
    </ul>
  </div>
</template>

<script>
import mqtt from 'mqtt';

export default {
  data() {
    return {
      client: null,
      messages: []
    };
  },
  mounted() {
    this.initMQTT();
  },
  methods: {
    initMQTT() {
      const options = {
        clientId: 'vue-client_' + Math.random().toString(16).substr(2, 8),
        clean: true,
        connectTimeout: 4000
      };
      const url="ws://"+"你的地址"+":8083/mqtt"  //例如ws://172.18.14.167:8083/mqtt
      this.client = mqtt.connect(url, options);

      this.client.on('connect', (e) => {
        this.subscribeTopics();
      });

      this.client.on('message', (topic, payload) => {
        this.messages.push({
          topic: topic,
          content: payload.toString()
        });
      });
    },
    subscribeTopics() {
      this.client.subscribe(['sensor/#'], { qos: 1 });
    }
  },
  beforeDestroy() {
    if (this.client) {
      this.client.end();
    }
  }
};
</script>