Websocket 客户端覆盖彼此的连接

Question

我正在尝试使用 Nodejs Express 服务器和 LitComponent-Client 实现服务器-客户端示例。当运行宁一个 1:1 配置时，服务器和客户端之间的通信工作完美。当启动第二个客户端时，数据传输停止工作，只有新客户端接收数据。

localhost:3001 上的所有客户端运行 - localhost:3000 上的服务器运行。

如何连续向多个客户端发送数据？

客户端

import short from 'short-uuid';
import { io } from 'socket.io-client';

...

constructor() {
    super();

    //Generate app id
    this.app_id = short.generate();
    console.log('# App-ID: ' + this.app_id);

    this.socket = io('ws://localhost:3000', { forceNew: true });

    this.socket.on('connect', () => {
      this.socket.emit('log', 'App-ID: ' + this.app_id);
    });

    this.socket.on('data', message => {
      this.receiveData(message);
    });

    this.socket.on('disconnect', function () {
      console.log('# Socket disconnected');
    });
  }

...

服务器

var app = require("express")();
const express = require("express");

var http = require("http").createServer(app);
var io = require("socket.io")(http, {
    cors: {
        origin: "http://localhost:3001",
        methods: ["GET", "POST"],
    },
});

let connectCounter = 0;

let sock;
io.on("connect", (socket) => {
    sock = socket;
    console.log("# " + socket.id + " | ■ App connected");
    connectCounter++;
    console.log("# New connection - now have " + connectCounter);
    socket.on("disconnect", () => {
        connectCounter--;
        console.log("# Lost connection - now have " + connectCounter);
    });
    socket.on("log", (message) => {
        console.log("# " + socket.id + " | " + message);
    });
});

function sendData(msg) {
    sock.emit("data", msg);
}

...

http.listen(3000, () => {
    console.log("# HTTP: listening on *:3000");
});

Answer 1

在服务器端你有：

let sock;
io.on("connect", (socket) => {
    sock = socket;
    ...
});

function sendData(msg) {
    sock.emit("data", msg);
}

你能看出这里有问题吗？每次新用户连接时，您都将他设置为全局 sock 然后您只发送到该套接字。您需要的是将所有套接字保存在某个集合中，如下所示：

let sockets = {};

io.on("connect", (socket) => {
    sockets[socket.id] = socket;
    ...
    socket.on("disconnect", () => {
        ...
        delete sockets[socket.id];
    });
});

function sendData(msg) {
    for (var socket_id in sockets) {
        sockets[socket_id].emit("data", msg);
    }
}

AFAIK socket.io 已经为你做到了，但我不记得具体的属性（自从我处理 socket.io 以来已经有一段时间了），所以你必须阅读 api.

Websocket 客户端覆盖彼此的连接

Websocket clients override connections of each other

websocket

node.js

express

socket.io

lit-html