JS websocket 实战——好友聊天

原文地址：websocket 实战——好友聊天

还不了解 websocket 的同鞋，请先学习阮一峰老师的 WebSocket 教程

websocket

  1. websocket 在实际项目中有着很广的应用，如好友聊天，异步请求，react-hot-loader 的热更新等等
  2. 本文前端采用原生 WebSocket，后端采用 express-ws 库 实现聊天通信
  3. 后端 mongodb 数据存储采用 mongoose 操作，不了解的可以先看看 文档 哦
  4. 聊天原理很简单，如下图:

简单版本

先撸个简单版本，能够实现用户与服务器之间的通信

  1. 前端：WsRequest 封装类
class WsRequest {  ws: WebSocket  constructor(url: string) {    this.ws = new WebSocket(url)    this.initListeners()  }  initListeners() {    this.ws.onopen = _event => console.log('client connect')    this.ws.onmessage = event => console.log(`来自服务器的信息：${event.data}`)    this.ws.onclose = _event => console.log('client disconnect')  }  send(content: string) {    this.ws.send(content)  }  close() {    this.ws.close()  }}// 使用const ws = new WsRequest('your_websocket_url') // 如: ws://localhost:4000/wsws.send('hello from user')
  1. 服务端：WsRouter 封装类，使用单例模式
import expressWs, { Application, Options } from 'express-ws';import ws, { Data } from 'ws';import { Server as hServer } from 'http';import { Server as hsServer } from 'https';class WsRouter {  static instance: WsRouter;  wsServer: expressWs.Instance;  clientMap: Map<string, ws>; // 保存所有连接的用户 id  constructor(    private path: string,    private app: Application,    private server?: hServer | hsServer,    private options?: Options  ) {    this.wsServer = expressWs(this.app, this.server, this.options);    this.app.ws(this.path, this.wsMiddleWare);    this.clientMap = new Map();  }  static getInstance(path: string, app: Application, server?: hServer | hsServer, options: Options = {}) {    if (!this.instance) {      this.instance = new WsRouter(path, app, server, options);    }    return this.instance;  }  wsMiddleWare = (wServer: any, _req: any) => {    this.clientMap.set(id, wServer);    this.broadcast('hello from server'); // send data to users    wServer.on('message', async (data: Data) => console.log(`来自用户的信息：${data.toString()}`));    wServer.on('close', (closeCode: number) => console.log(`a client has disconnected: ${closeCode}`));  }  broadcast(data: Data) { // 全体广播    this.clientMap.forEach((client: any) => {      if (client.readyState === ws.OPEN) {        client.send(data);      }    });  }}export default WsRouter.getInstance;// 使用：bootstrap.tsconst server = new InversifyExpressServer(container);// 注：本项目后端使用的是 [Inversify](https://github.com/inversify) 框架// 具体传的 private server?: hServer | hsServer 参数值，请类比改变server.setConfig((app: any) => WsRouter('/ws/:id', app))server.build().listen(4000);

升级版本

要实现好友通信，在前后端的 send 方法中，当然要指定 from 和 to 的用户

再者，后台要记录发送的消息，也必须要有好友表的主键 friendId，表示为这两个人之间的消息

  1. mongoose 数据存储
// user.tsconst userSchema = new Schema(  {    name: { type: String, required: true, unique: true }  });export default model('User', userSchema);// friend.ts 两个用户之间的好友关系import { Schema, model, Types } from 'mongoose';const FriendSchema = new Schema(  {    user1: { type: Types.ObjectId, ref: 'User', required: true }, // user1Id < user2Id    user2: { type: Types.ObjectId, ref: 'User', required: true }  });export default model('Friend', FriendSchema);// message.tsconst MessageSchema = new Schema(  {    friend: { type: Types.ObjectId, ref: 'Friend', required: true }, // 关联 Friend 表    from: String,    to: String,    content: String,    type: { type: String, default: 'text' },  });export default model('Message', MessageSchema);
  1. 接口说明
type msgType = 'text' | 'emoji' | 'file'interface IMessage {  from: string  to: string  content: string  type: msgType}
  1. 前端：WsRequest 封装类
import { IMessage, msgType } from './interface'export default class WsRequest {  ws: WebSocket  constructor(url: string, private userId: string) {    this.ws = new WebSocket(`${url}/${this.userId}`)    this.initListeners()  }  initListeners() {    this.ws.onopen = _event => console.log('client connect')    this.ws.onmessage = event => {      const msg: IMessage = JSON.parse(event.data)      console.log(msg.content)    }    this.ws.onclose = _event => console.log('client disconnect')  }  // friendId 指 Friend Model 的 _id  async send(friendId: string, content: string, receiverId: string, type: msgType = 'text') {    const message: IMessage = { from: this.userId, to: receiverId, content, type }    await this.ws.send(JSON.stringify({ friend: friendId, ...message }))  }  close() {    this.ws.close()  }}// 使用const ws = new WsRequest('your_websocket_url', 'your_user_id') // example: ws://localhost:4000/wsawait wsRequest.send('Friend_model_id', '你好啊，jeffery', 'jeffery_id')
  1. 服务端：WsRouter 封装类，使用单例模式
import expressWs, { Application, Options } from 'express-ws';import ws, { Data } from 'ws';import { Server as hServer } from 'http';import { Server as hsServer } from 'https';import Message, { IMessage } from 'models/message';import Friend from 'models/friend';class WsRouter {  static instance: WsRouter;  wsServer: expressWs.Instance;  clientMap: Map<string, ws>; // 保存所有连接的用户 id  constructor(    private path: string,    private app: Application,    private server?: hServer | hsServer,    private options?: Options  ) {    this.wsServer = expressWs(this.app, this.server, this.options);    this.app.ws(this.path, this.wsMiddleWare);    this.clientMap = new Map();  }  static getInstance(path: string, app: Application, server?: hServer | hsServer, options: Options = {}) {    if (!this.instance) {      this.instance = new WsRouter(path, app, server, options);    }    return this.instance;  }  wsMiddleWare = (wServer: any, req: any) => {    const { id } = req.params; // 解析用户 id    wServer.id = id;    this.clientMap.set(id, wServer);    wServer.on('message', async (data: Data) => {      const message: IMessage = JSON.parse(data.toString());      const { _id } = await new Message(message).save(); // 更新数据库      this.sendMsgToClientById(message);    });    wServer.on('close', (closeCode: number) => console.log(`a client has disconnected, closeCode: ${closeCode}`));  };  sendMsgToClientById(message: IMessage) {    const client: any = this.clientMap.get(message.to);    if (client) {      client!.send(JSON.stringify(message));    }  }  broadcast(data: Data) {    this.clientMap.forEach((client: any) => {      if (client.readyState === ws.OPEN) {        client.send(data);      }    });  }}export default WsRouter.getInstance;// 使用：bootstrap.tsconst server = new InversifyExpressServer(container);// 注：本项目后端使用的是 [Inversify](https://github.com/inversify) 框架// 具体传的 private server?: hServer | hsServer 参数值，请类比改变server.setConfig((app: any) => WsRouter('/ws/:id', app))server.build().listen(4000);
  1. 心跳检测

参考：

  • ws faq: how-to-detect-and-close-broken-connections
// 服务端wsMiddleWare = (wServer: any, req: any) => {  const { id } = req.params;  wServer.id = id;  wServer.isAlive = true;  this.clientMap.set(id, wServer);  wServer.on('message', async (data: Data) => {...});  wServer.on('pong', () => (wServer.isAlive = true));}initHeartbeat(during: number = 10000) {  return setInterval(() => {    this.clientMap.forEach((client: any) => {      if (!client.isAlive) {        this.clientMap.delete(client.id);        return client.terminate();      }      client.isAlive = false;      client.ping(() => {...});    });  }, during);}

在线测试

一、准备

  1. 为方便大家测试，可以访问线上的服务端接口: wss://qaapi.omyleon.com/ws，具体使用要附上用户 id，如：wss://qaapi.omyleon.com/ws/asdf...，参见 升级版本的 websocket
  2. 客户端：可以使用谷歌插件：Simple WebSocket Client；也可以访问在线项目，使用项目提供的客户端，具体参见：qa-app
  3. 使用线上的一对好友信息
  • friend: jeffery 与 testuser => _id: 5d1328295793f14020a979d5
  • jeffery => _id: 5d1327c65793f14020a979ca
  • testuser => _id: 5d1328065793f14020a979cf

二、实际演示

  1. 打开 WebSocket Client 插件，输入测试链接，如下图：
wss://qaapi.omyleon.com/ws/5d1327c65793f14020a979ca

  1. 点击 Open，下方 Status 显示 Opened 表示连接成功

  1. 发送消息，请根据 IMessage 接口来发送，当然还要附上 friendId，否则不能对应到相应的好友关系上
{  "friend": "5d1328295793f14020a979d5",  "from": "5d1327c65793f14020a979ca",  "to": "5d1328065793f14020a979cf",  "content": "你好呀，testuser，这是通过 simple websocket client 发送的消息",  "type": "text"}

  1. 同时用 simple websocket client 连接另一个用户，会收到发来的消息

  1. 同理，在另一个 client 中改变 from 和 to，就能回复消息给对方
wss://qaapi.omyleon.com/ws/5d1328065793f14020a979cf{  "friend": "5d1328295793f14020a979d5",  "from": "5d1328065793f14020a979cf",  "to": "5d1327c65793f14020a979ca",  "content": "嗯嗯，收到了 jeffery，这也是通过 simple websocket client 发送的",  "type": "text"}

  1. 补充，在线上项目 qa-app 中，也是用的是个原理，只不过在显示时候做了解析，只显示了 content 字段，而在这个简易的测试客户端中没有做其他处理

源码获取

  1. 前端：qa-app app/websocket/index.ts
  2. 后端：qa-app-server server/wsRouter/index.ts
  3. 线上地址，去看看 -> https://qa.omyleon.com