WebSocket

概述

ACE NestJS Starter 集成 Socket.io 提供实时通信功能，支持双向通信、房间管理和事件广播。

核心特性

• 实时通信: 双向数据传输
• 房间管理: 分组广播
• 认证授权: JWT 认证
• 断线重连: 自动重连机制
• 消息确认: 消息送达确认

基础配置

Gateway 配置

// src/websocket/websocket.gateway.ts
import {
  WebSocketGateway,
  WebSocketServer,
  SubscribeMessage,
  OnGatewayConnection,
  OnGatewayDisconnect,
} from '@nestjs/websockets';
import { Server, Socket } from 'socket.io';

@WebSocketGateway({
  cors: {
    origin: '*',
  },
  namespace: 'chat',
})
export class ChatGateway implements OnGatewayConnection, OnGatewayDisconnect {
  @WebSocketServer()
  server: Server;

  async handleConnection(client: Socket) {
    console.log(`Client connected: ${client.id}`);
  }

  async handleDisconnect(client: Socket) {
    console.log(`Client disconnected: ${client.id}`);
  }

  @SubscribeMessage('message')
  handleMessage(client: Socket, payload: any) {
    this.server.emit('message', payload);
  }
}

认证集成

JWT 认证

@Injectable()
export class WsJwtGuard implements CanActivate {
  constructor(private jwtService: JwtService) {}

  canActivate(context: ExecutionContext): boolean {
    const client = context.switchToWs().getClient<Socket>();
    const token = client.handshake.auth.token;

    try {
      const payload = this.jwtService.verify(token);
      client.data.user = payload;
      return true;
    } catch (err) {
      client.disconnect();
      return false;
    }
  }
}

房间管理

@SubscribeMessage('joinRoom')
handleJoinRoom(client: Socket, room: string) {
  client.join(room);
  client.to(room).emit('userJoined', client.data.user);
}

@SubscribeMessage('leaveRoom')
handleLeaveRoom(client: Socket, room: string) {
  client.leave(room);
  client.to(room).emit('userLeft', client.data.user);
}

@SubscribeMessage('roomMessage')
handleRoomMessage(client: Socket, payload: { room: string, message: string }) {
  this.server.to(payload.room).emit('message', {
    user: client.data.user,
    message: payload.message,
  });
}

客户端集成

JavaScript 客户端

import io from 'socket.io-client';

const socket = io('http://localhost:3000/chat', {
  auth: {
    token: localStorage.getItem('accessToken'),
  },
});

socket.on('connect', () => {
  console.log('Connected');
  socket.emit('joinRoom', 'general');
});

socket.on('message', (data) => {
  console.log('New message:', data);
});

高级功能

• 消息队列集成
• 分布式部署（Redis Adapter）
• 消息持久化
• 离线消息

最佳实践

1. 使用命名空间隔离功能
2. 实现心跳机制
3. 消息大小限制
4. 连接数限制
5. 错误处理

下一步

• 实时聊天示例 - 聊天室实现
• 性能优化 - WebSocket 优化
• 监控 - 连接监控