node.js 在浏览器中接收 WebSocket ArrayBuffer 数据 - 接收字符串
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Receiving WebSocket ArrayBuffer data in the browser - receiving string instead
提问by svinja
I have a node.js server application and a browser client. Sending ArrayBufferdata browser -> server works perfectly, but server -> browser results in a string "[object ArrayBuffer]"being received. This happens in the latest versions of both Chrome and Firefox.
我有一个 node.js 服务器应用程序和一个浏览器客户端。发送ArrayBuffer数据浏览器 -> 服务器工作正常，但服务器 -> 浏览器会导致"[object ArrayBuffer]"接收到一个字符串。这发生在 Chrome 和 Firefox 的最新版本中。
Server:
服务器：
var serverPort = 9867;
// dependencies
var webSocketServer = require('websocket').server;
var http = require('http');
var players = {};
var nextPlayerId = 0;
// create http server
var server = http.createServer(function(request, response) { });
server.listen(serverPort, function() {
console.log((new Date()) + " Server is listening on port " + serverPort);
});
// create websocket server
var wServer = new webSocketServer({ httpServer: server });
// connection request callback
wServer.on('request', function(request) {
var connection = request.accept(null, request.origin);
connection.binaryType = "arraybuffer";
var player = {};
player.connection = connection;
player.id = nextPlayerId;
nextPlayerId++;
players[player.id] = player;
console.log((new Date()) + ' connect: ' + player.id);
// message received callback
connection.on('message', function(message) {
if (message.type == 'binary' && 'binaryData' in message && message.binaryData instanceof Buffer) {
// this works!
console.log('received:');
console.log(message);
}
});
// connection closed callback
connection.on('close', function(connection) {
console.log((new Date()) + ' disconnect: ' + player.id);
delete players[player.id];
});
});
function loop() {
var byteArray = new Uint8Array(2);
byteArray[0] = 1;
byteArray[0] = 2;
for (var index in players) {
var player = players[index];
console.log('sending: ');
console.log(byteArray.buffer);
player.connection.send(byteArray.buffer);
}
}
timerId = setInterval(loop, 500);
Client:
客户：
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<script type="text/javascript">
window.WebSocket = window.WebSocket || window.MozWebSocket;
var connection = new WebSocket('ws://127.0.0.1:9867');
connection.binaryType = "arraybuffer";
// most important part - incoming messages
connection.onmessage = function (event) {
document.getElementById("log").innerHTML += typeof(event.data) + ' ';
document.getElementById("log").innerHTML += event.data + ' ';
if (event.data instanceof ArrayBuffer) {
// string received instead of a buffer
}
};
window.onkeydown = function(e) {
var byteArray = new Uint8Array(2);
byteArray[0] = 1;
byteArray[1] = e.keyCode;
connection.send(byteArray.buffer);
};
</script>
<div id='log'>Log: </div>
</body>
</html>
What am I doing wrong?
我究竟做错了什么？
Edit:
编辑：
From the node.js websocket source:
来自 node.js websocket 源代码：
WebSocketConnection.prototype.send = function(data, cb) {
if (Buffer.isBuffer(data)) {
this.sendBytes(data, cb);
}
else if (typeof(data['toString']) === 'function') {
this.sendUTF(data, cb);
}
So if you use an Uint8Array, it sends the data as a string, instead of using sendBytes, as sendBytesneeds a Bufferobject. As in the answer below, I need sendBytes. As I can't pass an ArrayBufferto sendBytes, I did this on the server:
因此，如果您使用Uint8Array，它会将数据作为字符串发送，而不是使用sendBytes，因为sendBytes需要一个Buffer对象。正如下面的答案，我需要sendBytes. 由于我无法传递ArrayBufferto sendBytes，我在服务器上执行了此操作：
function loop() {
var buffer = new Buffer(2);
buffer[0] = 1;
buffer[1] = 2;
for (var index in players) {
var player = players[index];
console.log('sending: ');
console.log(buffer);
player.connection.send(buffer);
}
}
Now it works.
现在它起作用了。
Conclusion:
结论：
While Chrome and Firefox websockets .send()a Uint8Arraybuffer as binary data, it seems node.js websockets send it as stringdata, and you need a Bufferbuffer to send binary.
虽然Chrome和Firefox的WebSockets.send()一个Uint8Array缓冲的二进制数据，似乎node.js中的WebSockets将其作为string数据，你需要一个Buffer缓冲区来发送二进制。
采纳答案by Tanaka Kenji
send binary data use sendBytes()method.
发送二进制数据使用sendBytes()方法。
回答by Janne
I've been playing with websockets recently and at least this seems to work:
我最近一直在玩 websockets，至少这似乎有效：
if(event.data instanceof ArrayBuffer)
{
var wordarray = new Uint16Array(event.data);
for (var i = 0; i < wordarray.length; i++)
{
console.log(wordarray[i]);
wordarray[i]=wordarray[i]+1;
}
console.log("End of binary message");
console.log("sending changes");
ws.send(wordarray.buffer);
}
Basically I'm just creating a new array based on event.data
基本上我只是基于 event.data 创建一个新数组
