使用nodejs客户端访问golang websocket服务器

Question

I am a newbie to NodeJS. Assume that I have a echo server implemented with Golang's websocket package:

package main

import (
    "code.google.com/p/go.net/websocket"
    "log"
    "net/http"
)

func EchoServer(ws *websocket.Conn) {
    var msg string
    websocket.Message.Receive(ws, &msg)
    log.Printf("Message Got: %s
", msg)
    websocket.Message.Send(ws, msg)
}

func main() {
    http.Handle("/echo", websocket.Handler(EchoServer))
    err := http.ListenAndServe(":8082", nil)
    if err != nil {
        panic(err.Error())
    }
}

What should the nodejs client code look like ?

Answer 1

I think this is what you're looking for. Quick example using your server code:

var WebSocketClient = require('websocket').client;

var client = new WebSocketClient();

client.on('connectFailed', function(error) {
    console.log('Connect Error: ' + error.toString());
});

client.on('connect', function(connection) {
    console.log('WebSocket client connected');
    connection.on('error', function(error) {
        console.log("Connection Error: " + error.toString());
    });
    connection.on('close', function() {
        console.log('echo-protocol Connection Closed');
    });
    connection.on('message', function(message) {
        if (message.type === 'utf8') {
            console.log("Received: '" + message.utf8Data + "'");
        }
    });

    connection.sendUTF("Hello world");
});

client.connect('ws://127.0.0.1:8082/echo', "", "http://localhost:8082");

To get this to work, you'll need to modify the WebsocketClient code in lib/WebSocketCLient.js. Comment these lines out (lines 299-300 on my machine):

        //this.failHandshake("Expected a Sec-WebSocket-Protocol header.");
        //return;

For some reason the websocket library you provided doesn't seem to send the "Sec-Websocket-Protocol" header, or at least the client doesn't find it. I haven't done too much testing, but a bug report should probably be filed somewhere.

Here's an example using a Go client:

package main

import (
    "fmt"
    "code.google.com/p/go.net/websocket"
)

const message = "Hello world"

func main() {
    ws, err := websocket.Dial("ws://localhost:8082/echo", "", "http://localhost:8082")
    if err != nil {
        panic(err)
    }
    if _, err := ws.Write([]byte(message)); err != nil {
        panic(err)
    }
    var resp = make([]byte, 4096)
    n, err := ws.Read(resp)
    if err != nil {
        panic(err)
    }
    fmt.Println("Received:", string(resp[0:n]))
}