Posted in Javascript onNovember 23, 2020
在一个应用中,websocket一般都是以单例形式存在的,即在整个应用中,websocket实例始终保持唯一。但有时我们要用到websocket实例的时候,可能websocket还没实例化,所以要做成异步的形式来获取实例。
一、封装。先创建 socket.ts 文件
import EventEmitter from 'events'; // 这里用到了 events 包 const ee = new EventEmitter(); class Ws { private wsUrl: string = ''; private socket: WebSocket | undefined; // socket实例 private lockReconnect: boolean = false; // 重连锁 private timeout: NodeJS.Timeout | undefined; // 初始化socket,一般在应用启动时初始化一次就好了,或者需要更换wsUrl public init(wsUrl: string) { this.wsUrl = wsUrl; this.createWebSocket(); } // 获取socket实例 public getInstance(): Promise<WebSocket> { return new Promise((resolve, reject) => { if (this.socket) { resolve(this.socket); } else { ee.on('socket', (state: string) => { if (state === 'success') { resolve(this.socket); } else { reject(); } }); } }); } // 创建socket private createWebSocket() { try { console.log('websocket 开始链接'); const socket = new WebSocket(this.wsUrl); socket.addEventListener('close', () => { console.log('websocket 链接关闭'); this.socket = undefined; this.reconnect(); }); socket.addEventListener('error', () => { console.log('websocket 发生异常了'); this.socket = undefined; this.reconnect(); }); socket.addEventListener('open', () => { // 可在此进行心跳检测 // this.heartCheck.start(); console.log('websocket open'); this.socket = socket; ee.emit('socket', 'success'); }); socket.addEventListener('message', (event) => { console.log('websocket 接收到消息', event); }); } catch (e) { console.log('socket catch error', e); this.reconnect(); } } // 重连 private reconnect() { if (this.lockReconnect) { return; } console.log('websocket 正在重新连接'); this.lockReconnect = true; //没连接上会一直重连,设置延迟避免请求过多 this.timeout && clearTimeout(this.timeout); this.timeout = setTimeout(() => { this.createWebSocket(); this.lockReconnect = false; }, 5000); } } export default new Ws();
二、引入并使用
import socket from '@/utils/ws'; socket .getInstance() .then((ws) => { // 这里的 ws 就是实例化后的 websocket,可以直接使用 websocket 原生 api console.log('getInstance ws', ws); ws.addEventListener('message', (event) => { console.log('ws 接收到消息', event); }); }) .catch(() => {});
以上就是记录一次websocket封装的过程的详细内容,更多关于websocket封装的资料请关注三水点靠木其它相关文章!
记录一次websocket封装的过程
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