如何使一个node.js应用程序在关闭套接字后继续监听?

时间:2014-11-16 23:27:21

标签: node.js sockets loops

我正在尝试设置一个node.js应用程序,该应用程序可以接收连接,并且一旦套接字结束,仍然会监听端口9001。我怎样才能做到这一点?这是我当前的代码(它在socket.end()之后没有关闭,但它不接受任何其他连接):

var net = require('net');
var mySocket;

var server = net.createServer(function(socket) {
    mySocket = socket;
    mySocket.on("connect", onConnect);
    mySocket.on("data", onData);
});

function onConnect() {
    console.log("Connected");
}

function onData(command) {
    if (command == "exit") {
        console.log("Exiting");
        mySocket.end();
    }
}

console.log("Waiting for incoming connections");
server.listen(9001);

我尝试在server.listen(9001);之后添加另一个socket.end();,但我收到了:Error: listen EADDRINUSE消息。 此外,该代码是否能够同时接收来自不同地址的多个连接,并单独处理它们?

这是完整的代码。执行时,node.js从Flash应用程序接收4个命令,并且正常工作(除了onConnect()函数似乎永远不会被调用),并且“exit;”命令正确关闭套接字,但如果我重新加载Flash应用程序,它不会连接到服务器

var net = require('net');
const PACKET_SEPARATOR = 59 // ;
var connection_ack = false;
var counter = 0;

var server = net.createServer(function(socket) {
    function onConnect() {
        console.log("Connected to Flash");
    }

    function dataHandler(command) {
        if (command[command.length - 1] != String.fromCharCode(PACKET_SEPARATOR) && connection_ack) {
       console.log("SEP : " + PACKET_SEPARATOR + " - last : " + command[command.length - 1] + " - ack " + connection_ack);
            console.log("CAUGHT EXCEPTION : WRONG PACKET FORMAT --- " + command + " --- " + command.length);
        }
        if (command == "exit;") {
            console.log("Received exit request from " + socket.address().address + ":" + socket.address().port + " (" + socket.address().family + "). Ending connection...");
            socket.end();
        }
        else if (command == "<policy-file-request/>\0") {
            socket.write('<cross-domain-policy>\n<allow-access-from domain="*" to-ports="*" />\n</cross-domain-policy>\0', 'utf8');
            console.log("Policy file sent to " + socket.address().address + ":" + socket.address().port);
            player1.pxacceleration = 0;
            player1.pyacceleration = 0;
            connection_ack = true;
        }
        else {
            console.log("Got data from " + socket.address().address + ":" + socket.address().port + " (" + socket.address().family + ")");
            console.log("--> " + command);
            counter++;
            socket.write("Received " + counter + " commands;", 'utf8');
            console.log("Sending : Received " + counter + " commands;");
        }
    }

    function onData(d) {
        var command = "";
        for (i=0; i <= d.length - 1; i++) {
            command += String.fromCharCode(d[i]);
            if (d[i] == PACKET_SEPARATOR || i == d.length - 1 && !connection_ack) {
                dataHandler(command);
                command = "";
            }
        }
    }

    socket.on("connect", onConnect);
    socket.on("data", onData);
});

console.log("Ready. Waiting for incoming connections");
server.listen(9001);
server.listen(80); //TODO : Remove?     

1 个答案:

答案 0 :(得分:1)

正如jfriend00所说,不推荐使用mySocket作为全局。请尝试以下方法。

var server = net.createServer(function(socket) {
    function onData(command) {
        if (command == "exit") {
            console.log("Exiting");
            socket.end();
        }
    }
    socket.on("connect", onConnect);
    socket.on("data", onData);
});
...

这首先消除了对全球的需求。这也应该允许多个套接字并防止原始错误。我认为。我是新来的,所以我想我们会看到。

修改 好的。我一直在通过telnet与您的代码进行交互。我还阅读了一些文档。首先,应将socket.on("connect", onConnect);侦听器(以及onConnect函数)移动到全局范围并更改为server.on("connection", onConnect);。这样做的原因是套接字事件侦听器connect是客户端侦听器。我们正在服务器端。新连接的服务器端侦听器是connection,服务器应该以与侦听特定端口上的连接相同的方式监听它。

这部分代码现在应该如下所示:

//more code up above here
....
    function onData(d) {
        var command = "";
        for (i=0; i <= d.length - 1; i++) {
            command += String.fromCharCode(d[i]);
            if (d[i] == PACKET_SEPARATOR || i == d.length - 1 && !connection_ack) {    
                dataHandler(command);
                command = "";
            }
        }
    }
    socket.on("data", onData);
});

function onConnect() {
    console.log("Connected to Flash");
}

server.on("connection", onConnect);
....
//more code below here

但是,代码不会通过telnet将exit识别为命令。我无法弄清楚这一点。既然你的问题没有涵盖这个问题,那可能只是我或你已经弄清楚了。

编辑2 下面的代码将其保留在本地。

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

    function onConnect() {
        console.log("Connected to Flash");
        socket.write("we're connected");
    }
....
    function onData(d) {
        var command = "";
        for (i=0; i <= d.length - 1; i++) {
            command += String.fromCharCode(d[i]);
            if (d[i] == PACKET_SEPARATOR || i == d.length - 1 && !connection_ack) {    
                dataHandler(command);
                command = "";
            }
        }
    }
    onConnect();
    socket.on("data", onData);
});