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[英]How to separate JSON data from ArrayBuffer receiving from websocket
[英]Receiving WebSocket ArrayBuffer data in the browser - receiving string instead
我有一個node.js服務器應用程序和一個瀏覽器客戶端。 發送ArrayBuffer
數據瀏覽器 - >服務器工作正常,但服務器 - >瀏覽器導致收到字符串"[object ArrayBuffer]"
。 這種情況發生在Chrome和Firefox的最新版本中。
服務器:
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);
客戶:
<!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>
我究竟做錯了什么?
編輯:
來自node.js websocket源:
WebSocketConnection.prototype.send = function(data, cb) {
if (Buffer.isBuffer(data)) {
this.sendBytes(data, cb);
}
else if (typeof(data['toString']) === 'function') {
this.sendUTF(data, cb);
}
因此,如果您使用Uint8Array
,它會將數據作為字符串發送,而不是使用sendBytes
,因為sendBytes
需要一個Buffer
對象。 如下面的答案,我需要sendBytes
。 因為我無法將ArrayBuffer
傳遞給sendBytes
,所以我在服務器上執行了此操作:
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);
}
}
現在它有效。
結論:
當Chrome和Firefox .send()
將Uint8Array
緩沖區作為二進制數據時,似乎node.js websockets將其作為string
數據發送,並且您需要一個Buffer
緩沖區來發送二進制文件。
我最近一直在玩websockets,至少這似乎有用:
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);
}
基本上我只是基於event.data創建一個新數組
使用sendBytes()
方法發送二進制數據。
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