如何通过Websocket发送arraybuffer作为二进制文件？

Question

我正在与Mozilla Europe合作开展一个项目.在这个项目中,我使用了由Worlize(服务器端)和Mozilla(客户端)的Nodeocket,Node.js尝试将文件从客户端上传到服务器.
我目前的目标是将一个arraybuffer文件发送到服务器.创建arraybuffer并发送它很好.
但是我的服务器告诉我这arraybuffer是一条utf8消息而不是二进制消息.

我误解了什么吗？如果没有,我该如何纠正？

客户端:

    reader = new FileReader();
    reader.readAsArrayBuffer(file);
    reader.onload = function(e) {
        connection.send(e.target.result); 
    };

服务器端:

ws.on('message', function(message,flags) {
if (!flags.binary) {
    //some code
}
else {
    console.log('It\'s a binary');
}

我也尝试Blob过,同样的结果.二进制部分是不可见的.

Answer 1

Gecko11.0 ArrayBuffer已经实现了对二进制数据的发送和接收支持.

connection = new WebSocket( 'ws://localhost:1740' );
connection.binaryType = "arraybuffer";
connection.onopen = onopen;
connection.onmessage = onmessage;
connection.onclose = onclose;
connection.onerror = onerror;

发送二进制数据:

function sendphoto() {
    imagedata = context.getImageData( 0, 0, imagewidth, imageheight );
    var canvaspixelarray = imagedata.data;
    var canvaspixellen = canvaspixelarray.length;
    var bytearray = new Uint8Array( canvaspixellen );
    for ( var i = 0; i < canvaspixellen; ++i ) {
        bytearray[i] = canvaspixelarray[i];
    }
    connection.send( bytearray.buffer );
    context.fillStyle = '#ffffff';
    context.fillRect( 0, 0, imagewidth, imageheight );
}

接收二进制数据:

if ( event.data instanceof ArrayBuffer ) {
    var bytearray = new Uint8Array( event.data );
    var tempcanvas = document.createElement( 'canvas' );
    tempcanvas.height = imageheight;
    tempcanvas.width = imagewidth;
    var tempcontext = tempcanvas.getContext( '2d' );
    var imgdata = tempcontext.getImageData( 0, 0, imagewidth, imageheight );
    var imgdatalen = imgdata.data.length;
    for ( var i = 8; i < imgdatalen; i++ ) {
        imgdata.data[i] = bytearray[i];
    }
    tempcontext.putImageData( imgdata, 0, 0 );
    var img = document.createElement( 'img' );
    img.height = imageheight;
    img.width = imagewidth;
    img.src = tempcanvas.toDataURL();
    chatdiv.appendChild( img );
    chatdiv.innerHTML = chatdiv.innerHTML + "<br />";
}

Answer 2

Note: Prior to version 11, Firefox only supported sending data as a string.

来源：https ://developer.mozilla.org/en/WebSockets/Writing_WebSocket_client_applications