node.js - Node.js 网络事件不会触发

Question

我有以下侦听连接和数据事件的示例，以将结果回显给侦听端口 8888 的其他 telnet 客户端。我的 telnet 会话连接到 locahost 很好，但没有回显输出。我正用头撞砖墙，试图找出问题所在。执行甚至没有达到“连接”事件。

/server.js

 var events = require('events');
    var net = require('net');
    var channel = new events.EventEmitter();
    channel.clients = {};
    channel.subscriptions = {};
    channel.on('join', function (id, client) {
        this.clients[id] = client;
        this.subscriptions[id] = function (senderId, message) {
            if (id != senderId) {
                this.clients[id].write(message);
            }
        }
        this.on('broadcast', this.subscriptions[id]);
    });
    var server = net.createServer(function (client) {
        var id = client.remoteAddress + ':' + client.remotePort;
        console.log(id);
        client.on('connect', function () {
            console.log('A new connection was made');
            channel.emit('join', id, client);
        });
        client.on('data', function (data) {
            data = data.toString();
            channel.emit('broadcast', id, data);
        });
    });

    server.listen(8888);

然后我在命令行中运行

node server.js
telnet 127.0.0.1 8888

Answer 1

当调用回调时net.createServer，这是因为隐式connection事件。所以你的代码应该是这样的：

var server = net.createServer(function (client) {

  // when this code is run, the connection has been established

  var id = client.remoteAddress + ':' + client.remotePort;
  console.log('A new connection was made:', id);

  channel.emit('join', id, client);

  client.on('data', function(data) {
    ...
  });

  client.on('end', function() {
    ...
  });
});

Answer 2

手册中有这样说；

net.createServer([options], [connectionListener])
创建一个新的 TCP 服务器。connectionListener 参数自动设置为“连接”事件的侦听器。

换句话说，您function (client) {已经收到了连接事件，并且在它已经被调度时添加一个监听器没有进一步的效果。