webrtc学习笔记六(datachannel+websocket)
程序员文章站
2022-07-08 16:42:34
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2020年5月12日更新
5年前的例子又不好使了，
出现错误
websocket Failed to execute 'send' on 'WebSocket': Still in CONNECTING state
参考：https://blog.csdn.net/bossxu_/article/details/102977802
原因是
pc.createOffer 的时候websocket还没建立完，socket.send出现问题，
把这段代码加到websocket.onopen事件里就好了：
只有datachannel的例子，websocket作为转发用，
建立连接后websocket就可以关了
server.js
webrtc_datachannle.html
5年前的例子又不好使了，
出现错误
websocket Failed to execute 'send' on 'WebSocket': Still in CONNECTING state
参考：https://blog.csdn.net/bossxu_/article/details/102977802
原因是
pc.createOffer 的时候websocket还没建立完，socket.send出现问题，
把这段代码加到websocket.onopen事件里就好了：
只有datachannel的例子，websocket作为转发用，
建立连接后websocket就可以关了
server.js
//http://www.blogjava.net/linli/archive/2014/10/21/418910.html
var express = require('express'),
app = express(),
server = require('http').createServer(app);
server.listen(3000);
app.get('/', function(req, res) {
res.sendfile(__dirname + '/webrtc.html');
});
var WebSocketServer = require('ws').Server,
wss = new WebSocketServer({server: server});
function writeObj(obj){
var description = "";
for(var i in obj){
var property=obj[i];
description+=i+" = "+property+"\n";
}
console.log(description);
}
// 存储socket的数组，这里只能有2个socket，每次测试需要重启，否则会出错
var wsc = [],
index = 1;
// 有socket连入
wss.on('connection', function(ws) {
console.log('connection:');
//writeObj(ws);
// 将socket存入数组
wsc.push(ws);
// 记下对方socket在数组中的下标，因为这个测试程序只允许2个socket
// 所以第一个连入的socket存入0，第二个连入的就是存入1
// otherIndex就反着来，第一个socket的otherIndex下标为1，第二个socket的otherIndex下标为0
var otherIndex = index--,
desc = null;
if (otherIndex == 1) {
desc = 'first socket';
} else {
desc = 'second socket';
}
// 转发收到的消息
ws.on('message', function(message) {
var json = JSON.parse(message);
//console.log('received (' + desc + '): ', json);
console.log('otherIndex ---('+desc+')(' + otherIndex + '): '+json.event);
wsc[otherIndex].send(message, function (error) {
if (error) {
console.log('Send message error (' + desc + '): ', error);
}
});
});
});
webrtc_datachannle.html
<html>
<body>
<button id="sendButton" onclick="sendData()">Send</button>
<textarea id="dataChannelSend" >abc</textarea>
<textarea id="dataChannelReceive" ></textarea>
<script>
var isCaller = window.location.href.split('#')[1];
var socket = new WebSocket("ws://127.0.0.1:3000");
socket.onopen=function(){ //这部分放到onopen事件里了 2020.05.12
console.log("socket on open --->");
if(isCaller){
console.log("------->createOffer");
pc.createOffer(function(desc){
// console.log(desc);
pc.setLocalDescription(desc);
console.log("---------------->pc.setLocal");
socket.send(JSON.stringify({
"event": "_offer",
"data": {
"sdp": desc
}
}));
}, function (error) {
console.log('Failure callback: ' + error);
});
}
}
socket.onmessage = function(event){
var json = JSON.parse(event.data);
//console.log('onmessage: ', json);
//如果是一个ICE的候选，则将其加入到PeerConnection中，否则设定对方的session描述为传递过来的描述
if( json.event === "_ice_candidate" ){
pc.addIceCandidate(new RTCIceCandidate(json.data.candidate));
} else {
pc.setRemoteDescription(new RTCSessionDescription(json.data.sdp));
console.log("---------------->pc.setRemote");
// 如果是一个offer，那么需要回复一个answer
if(json.event === "_offer") {
console.log("------->createAnswer");
pc.createAnswer(function(desc){
pc.setLocalDescription(desc);
console.log("---------------->pc.setLocal");
socket.send(JSON.stringify({
"event": "_answer",
"data": {
"sdp": desc
}
}));
}, function (error) {
console.log('Failure callback: ' + error);
});
}else{
console.log("------->receive Answer---('"+json.event+"')");
}
}
};
var iceServer = null;
var pc = new webkitRTCPeerConnection(iceServer,{optional: [{RtpDataChannels: true}]});
try {
sendChannel = pc.createDataChannel('sendDataChannel',{reliable: true});
} catch (e) {
alert('createDataChannel() failed with exception: ' + e.message);
}
sendChannel.onopen = console.log('--Send channel open state is : ' +sendChannel.readyState);
sendChannel.onclose = console.log('--Send channel close state is: ' +sendChannel.readyState);
// 发送ICE候选到其他客户端
pc.onicecandidate = function(event){
console.log("onicecandidate----------->");
if (event.candidate !== null) {
console.log("event.candidate != null");
socket.send(JSON.stringify({
"event": "_ice_candidate",
"data": {
"candidate": event.candidate
}
}));
}else{
console.log("event.candidate == null");
}
};
sendChannel.onmessage = function(event) {
console.log("-sendChannel--★★★★★---ondatachannel");
document.getElementById('dataChannelReceive').value = event.data;
};
function sendData() {
var data = document.getElementById('dataChannelSend').value;
console.log("---->>>>sendData():"+data);
sendChannel.send(data);
}
// if(isCaller){ //这部分放到onopen事件里了 2020.05.12
// console.log("------->createOffer");
// pc.createOffer(function(desc){
// // console.log(desc);
// pc.setLocalDescription(desc);
// console.log("---------------->pc.setLocal");
// socket.send(JSON.stringify({
// "event": "_offer",
// "data": {
// "sdp": desc
// }
// }));
// }, function (error) {
// console.log('Failure callback: ' + error);
// });
// }
</script>
</body>
</html>
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