TS MQTT封装

2023-12-29 09:03 由 ljh_ybxj 发表于 #前端开发

TS MQTT封装

导入相关包

npm i mqtt
npm i lodash

guid 随机生成就行，具体可以参考百度或者随便生成一个随机数*

代码封装

import mqtt from 'mqtt'
import type { MqttClient, OnMessageCallback, IClientOptions, IClientPublishOptions, IPublishPacket } from 'mqtt'
import { getGuid } from '@/common/basic'
import { without, uniq } from 'lodash'

export type TPublishFormat = {
  topic: string
  payload: string | Buffer
  opts?: IClientPublishOptions
}
export type TMessageCallback<T> = (topic: string, payload: T) => void

export interface IMqClientOptions extends IClientOptions {
  connectCb?: () => void
  errorCb?: (e: Event) => void
  reconnectCb?: () => void
}

export default class MQTT {
  private _type: string
  private _url: string
  private _opt: IMqClientOptions // mqtt配置
  public client!: MqttClient
  public topicArr: Array<string> = []

  constructor(url: string, opt?: IMqClientOptions, type: string = 'Web') {
    this._type = type
    this._url = url
    this._opt = {
      clean: true,
      clientId: this._type + '_' + getGuid(), // 客户端分类唯一
      connectTimeout: 3000, // 超时时间
      reconnectPeriod: 1000, //重连超时
      ...(opt && opt),
    }
    this._init()
  }

  private _init() {
    this.destroy()
    this.client = mqtt.connect(this._url, this._opt)
    this.client.on('connect', () => {
      this._opt.connectCb && this._opt.connectCb()
      console.log(this._url + '连接成功...')
    })
    this.client.on('error', (error: any) => {
      this._opt.errorCb && this._opt.errorCb(error)
      console.log(this._url + '异常中断...')
    })
    this.client.on('reconnect', () => {
      this._opt.reconnectCb && this._opt.reconnectCb()
      console.log(this._url + '重新连接...')
    })
  }

  /**
   * 函数“unSubscribe”是一个 TypeScript 函数，用于取消订阅一个或多个主题，并返回一个 Promise，该 Promise 解析为一个布尔值，指示取消订阅是否成功。
   * @param {string | string[]} topic - topic 参数可以是字符串或字符串数组。它代表客户端想要取消订阅的主题。
   * @returns 正在返回 Promise。
   */
  public unSubscribe(topic: string | string[]) {
    return new Promise((resolve: (isOk: boolean) => void) => {
      this.client &&
        !this.client.disconnected &&
        this.client
          .unsubscribeAsync(topic)
          .then((result) => {
            if (typeof topic === 'string') {
              topic = [topic]
            }
            //去重
            this.topicArr = without(this.topicArr, ...topic)
            console.log(topic, this.topicArr, '取消订阅成功...')
            resolve(true)
          })
          .catch((err) => {
            console.log(topic, '取消订阅失败...')
            resolve(false)
          })
    })
  }

  /**
   * 函数“onSubscribe”是一个 TypeScript 函数，它订阅一个或多个主题并返回一个 Promise，该 Promise 解析为一个布尔值，指示订阅是否成功。
   * @param {string | string[]} topic - topic 参数可以是字符串或字符串数组。它代表您要订阅的主题。
   * @returns 一个 Promise，解析为布尔值，指示订阅是否成功。
   */
  public onSubscribe(topic: string | string[]) {
    if (typeof topic === 'string') {
      topic = [topic]
    }
    const topicOk: Array<string> = without(topic, ...this.topicArr)
    return new Promise((resolve: (isOk: boolean) => void) => {
      this.client &&
        !this.client.disconnected &&
        topicOk.length > 0 &&
        this.client
          .subscribeAsync(topic)
          .then((result) => {
            this.topicArr.push(...topicOk)
            this.topicArr = uniq(this.topicArr)
            console.log(topicOk, this.topicArr, '订阅成功...')
            resolve(true)
          })
          .catch((err) => {
            console.log(topicOk, '订阅失败...')
            resolve(false)
          })
    })
  }

  /**
   * 函数“onPublish”使用客户端向主题发布消息，并返回一个解析为布尔值的 Promise，指示发布是否成功。
   * @param {TPublishFormat} format - format参数的类型为TPublishFormat，它是一个包含两个属性的对象：topic和message。 topic
   * 属性表示消息将发布到的主题，message 属性表示将发布的实际消息。
   * @returns 正在返回 Promise。
   */
  public onPublish(format: TPublishFormat) {
    return new Promise((resolve: (isOk: boolean) => void) => {
      this.client &&
        !this.client.disconnected &&
        this.client
          .publishAsync(format.topic, format.payload, format.opts)
          .then((result) => {
            console.log('发布消息成功...')
            resolve(true)
          })
          .catch((err) => {
            console.log('发布消息失败...')
            resolve(false)
          })
    })
  }

  //收到的消息
  public onMessage<T = any>(callback: TMessageCallback<T>) {
    this.client &&
      !this.client.disconnected &&
      this.client.on('message', (topic: string, payload: Buffer) => {
        try {
          callback && callback(topic, JSON.parse(payload.toString()))
        } catch (err) {
          console.log('无法执行JSON.parse...')
          callback && callback(topic, payload.toString() as T)
        }
      })
  }

  //销毁
  public destroy() {
    console.log('销毁...')
    this.client && this.client.end()
    this.topicArr = []
  }
}

使用

//通过开源公共服务器测试，切换成自家服务器就行了
const mqtt = new MQTT('mqtt://broker.emqx.io:8083/mqtt', { username: 'emqx_test', password: 'emqx_test' })
mqtt.onSubscribe('/test/ss')
mqtt.onMessage((topic, message) => {
  console.log(topic, message)
})

setTimeout(() => {
  mqtt.onPublish({ topic: '/test/ss', payload: '测试1111' })
}, 3000);