WS+Nest：服务端和客户端实现
上一篇文章使用 socket.io，但这玩意儿版本兼容性差，API 不稳定，而且维护方可能会跑路。本文简要给出一个使用 WS 库的例子。
服务端：
1import { WebSocketServer, SubscribeMessage, OnGatewayConnection, OnGatewayDisconnect, WebSocketGateway, MessageBody } from '@nestjs/websockets';
2import { Server, WebSocket } from 'ws';
3
4@WebSocketGateway()
5export class EventsGateway implements OnGatewayConnection, OnGatewayDisconnect {
6 @WebSocketServer()
7 server: Server;
8
9 async handleConnection(ws: WebSocket) {
10 console.log('Client connected');
11 }
12 @SubscribeMessage('hello')
13 onEvent(@MessageBody() data: any) {
14 console.log("[Events:hello] data: ", data)
15 return data
16 }
17 async handleDisconnect() {
18 console.log('Client disconnected');
19 }
20}
bootstrap
1import { NestFactory } from '@nestjs/core';
2import { AppModule } from './app.module';
3import { WsAdapter } from '@nestjs/platform-ws';
4
5async function bootstrap() {
6 const app = await NestFactory.create(AppModule);
7 app.useWebSocketAdapter(new WsAdapter(app));
8 await app.listen(3000);
9 console.log(`Application is running on: ${await app.getUrl()}`);
10}
11bootstrap();
客户端：
1const WebSocket = require('ws');
2
3const socket = new WebSocket('ws://localhost:3000');
4
5socket.on('open', (client) => {
6 console.log('Connected to the WebSocket server');
7 socket.send(JSON.stringify({
8 event: 'hello',
9 data: 'Hello from client',
10 }));
11});
12
13socket.on('message', (data) => {
14 console.log('Message from server: ', data.toString());
15});
16
17socket.on('close', () => {
18 console.log('Disconnected from the WebSocket server');
19});
20
21socket.on('error', (error) => {
22 console.error('WebSocket error: ', error);
23});
注意：服务端使用 @SubscribeMessage('hello') 注解的效果相当于在 handleConnection 中手动 on('message') 并解码 JSON。其它的官网都有不废话。