Unable to connect to a websocket in node js - javascript

I have a websocket with URL "ws://localhost:1122" running in my machine. I am able to connect to the websocket when using it with normal javascript and deploying it in a jetty server.
But while using node js I could not connect to the web socket. I use the following code in both cases
var socket = new WebSocket(URL);
While using node js I have addded the following var WebSocket = require("ws"). But the readyState of the socket never become OPEN in node js.
Is there anything I am missing in node js because while using jetty as a server and normal javascript I am able to connect to the websocket.
Here is my app.js
var http = require('http');
http.createServer(function (req, res) {
res.writeHead(200, { 'Content-Type': 'text/plain' });
res.end('Hello World\n');
}).listen(1131, "localhost");
var WebSocket = require("ws");
var wsUri = "ws://localhost:1122";
var socket;
printer();
function printer() {
socket = new WebSocket(wsUri);
console.log(socket.readyState);
}

Because of the asynchronous nature of Node.js, socket.readyState doesn't immediately reflect the state of the connection.
Instead, you should use the event emitter interface to check if/when the connection is being made:
socket = new WebSocket(wsUri);
socket.on('open', function() {
console.log('connection opened');
}).on('close', function() {
console.log('connection closed');
}).on('error', function(e) {
console.log('connection error', e);
});

Related

WebSocket stops working in Vue/Node application

I have a Node/Vue application. I am consuming a WebSocket from Binance, a crypto exchange. I can see the quotes on the server console as I log them, I can send them to the browser for a short period of time before the client stops logging them.
Browser just using WebSocket API
Node using ws library
Node code, this I am running as it's own service as its just this.
'use strict';
const WebSocket = require('ws');
const binanceWS = new WebSocket('wss://stream.binance.com:9443/ws/btcusdt#trade')
const server = new WebSocket.Server({ port: 5002 });
//websocket connection event will return a socket you can later use
binanceWS.on("open", function() {
console.log("connected to Binance");
});
binanceWS.on('message', function(data){
console.log(data);
server.on('connection', function connection(ws){
console.log("Connected a new client");
ws.send(data);
});
server.on('closed', function (id){
console.log("connection closed");
console.log(id);
});
server.on('error', function (err){
console.log(err)
})
})
On the Client side I am using Vue and in the app.js file I have this on the created hook.
let socket = new WebSocket("ws://localhost:5002")
socket.addEventListener('message', function(event){
let quotes = JSON.parse(event.data);
console.log(quotes.p)
});
socket.addEventListener('error', function(event){
console.log("closing because " + event);
})
Right now I am only listening to the consoles in the above app.vue file.
What I see in the browser console is a lot of quotes, then they stop after a second or 2. There can be over a thousand quotes in some times. Then on occasion I see a console.log('created') that I have in a child component of app.vue. In many cases this is the last thing in the console after hundreds of quotes.
In the console.log for the server I see a lot of sessions being created with one page refresh. So much that it fills my console.
So I'm not sure I am creating the connections correcly, I am not sure if Vue is somehow stopping the console.log's?
I don't see any errors anywhere and the entire time in my server console the Binance API continues streaming.
you have to write server event listener outside binance on message handler;
then you can pass messages from binance to the server by emitting new event to the server
on receiving message from binance you can send data to all connection on the server
Or Try this code I think it will work :
'use strict';
const WebSocket = require('ws');
const binanceWS = new WebSocket('wss://stream.binance.com:9443/ws/btcusdt#trade')
const server = new WebSocket.Server({ port: 5002 });
server.on('connection', function connection(ws){
console.log("Connected a new client");
});
server.on('closed', function (id){
console.log("connection closed");
console.log(id);
});
server.on('error', function (err){
console.log(err)
})
//websocket connection event will return a socket you can later use
binanceWS.on("open", function() {
console.log("connected to Binance");
});
binanceWS.on('message', function(data){
console.log(data);
server.clients.forEach(function each(client) {
if (client.readyState === WebSocket.OPEN) {
client.send(data);
}
});
})

Node.js Server crashed when Refresh Browser

I tried to build a chat box server by node.js. When the browser requestes the page, it workes well at first. But when I refresh the page, the Server crashes.
Below is the error message:
events.js:183
throw er; // Unhandled 'error' event
^
Error: read ECONNRESET
at _errnoException (util.js:1022:11)
at TCP.onread (net.js:615:25)
I used the node --inspect index.js, but could not find the point.
Below is the code of index.js:
const http = require('http');
const fs = require('fs');
const extract = require('./extract');
const wss = require('./websockets-server');
var handleError = function (err,res) {
res.writeHead(404);
res.end();
}
var server = http.createServer(function (req, res) {
console.log("Responding to a request.");
var filePath = extract(req.url);
console.log("filePath:"+filePath);
fs.readFile(filePath,function (err,data) {
if(err){
handleError(err,res);
return;
}else {
res.end(data);
}
})
})
server.listen(3000);
When I comment the 4th line, the import of websockets-server. Server works well when I refresh the page. Maybe it's about the websocket while it works without websocket.
Below is code of websockets-server.js:
const WebSocket = require('ws');
var WebSocketServer = WebSocket.Server;
var port = 3001;
var ws = new WebSocketServer({
port:port
});
var message = [];
console.log('websockets server started');
ws.on('connection', function (socket) {
console.log('client connection established');
message.forEach(function (msg) {
socket.send(msg);
})
socket.on('message', function (data) {
console.log('message received: ' + data);
message.push(data);
ws.clients.forEach(function (clientSocket) {
clientSocket.send(data);
});
});
});
Does the problem is about the websocket? Whether should I do process when the client shutdown the connection with the server while refreshing the page.
extract.js below:
const path = require('path');
var extractFilePath = function (url) {
var filePath;
var fileName = 'index.html';
if(url.length > 1){
fileName = url.substring(1);
}
console.log('The fileName is: ' + fileName);
filePath = path.resolve(__dirname, 'app', fileName);
return filePath;
}
module.exports = extractFilePath;
I guess that you maybe execute var ws = new WebSocket("ws://localhost:3001"); in html file. I haven't figured out exact reason about your error as I'm not proficient in WebSocket. But there is a solution:
window.onbeforeunload = function () {
ws.close();
}
close connection before reload, then the error will not reappear.
You need to add an error listener on the socket. Error listener only on the websocket instance does not help in this case.
socket.on('error', function(e){
console.log(e);
});
The ECONNRESET error means that the other side (browser) closed the connection abruptly. On browser refresh, browser simple killed the connection with the websocket server.
To solve this, you have to listen for the error event on the websocket server instance.
// listen for "error" event so that the whole app doesn't crash
wss.on("error", function(error){
console.log(error);
}
I was having the same problem, but it resolved after this command:
npm install #ionic/app-scripts#nightly --save-dev

Node js server not working

I am trying to make a node js server with ws module. But it's not working. It says upgrade required.
My server side code:
var WebSocketServer = require('ws').Server;
wss = new WebSocketServer({port: 8080});
wss.on('connection', function(ws) {
ws.on('message', function(message) {
console.log('Msg received in server: %s ', message);
});
ws.send('Msg from server');
});
Client side code:
var WebSocket = require('ws');
var ws = new WebSocket('ws://localhost:8080/');
ws.on('open', function() {
ws.send('Msg from client');
});
ws.on('message', function(data, flags) {
console.log('Msg received in client: %s ', data);
});
Running npm update as an administrator should update the packages and solve your issue.
Here is a similar issue reported fixed by another user.
I didn't able to fix the problem. Then I used Socket.io. It works well.

Connecting to a test websocket server works, but connecting to my Node.js server fails

I'm using the code below to test websockets on my browser:
this.webSocket = new WebSocket("ws://echo.websocket.org");
this.webSocket.onopen = function(evt) {
cc.log("Send Text WS was opened.");
};
this.webSocket.onmessage = function(evt) {
this.socketSendTextTimes++;
var textStr = "response text msg: " + evt.data + this.socketSendTextTimes;
cc.log(textStr);
};
The code works well, but if I connect to my own server running the code below:
var http = require('http');
var io = require('socket.io');
var server = http.createServer(function(req, res) {
// Send HTML headers and message
res.writeHead(200,{ 'Content-Type': 'text/html' });
res.end('<h1>Hello!</h1>');
});
var socket = io.listen(server);
socket.set('destroy upgrade', false);
socket.on('connection', function(client) {
client.on('message', function(event) {
console.log('Received message from client!', event);
});
client.on('disconnect', function() {
console.log('Server has disconnected');
});
});
server.listen(8080);
console.log('start to listen');
My browser displays:
hello!
But the listening socket does not do anything. How can I connect to the Socket.IO server using websockets?
Socket.IO uses alternate transport methods than the native websocket, even when emulating websockets themselves. You will need the client library to connect to Socket.IO sockets.

Insert getusermedia to node.js and socket.io based chat engine

I have this code running in
Client side:
$(function(){
var iosocket = io.connect();
iosocket.on('connect', function () {
$('#incomingChatMessages').append($('<li>Connected</li>'));
iosocket.on('message', function(message) {
$('#incomingChatMessages').append($('<li></li>').text(message));
});
iosocket.on('disconnect', function() {
$('#incomingChatMessages').append('<li>Disconnected</li>');
});
});
$('#outgoingChatMessage').keypress(function(event) {
if(event.which == 13) {
event.preventDefault();
iosocket.send($('#outgoingChatMessage').val());
$('#incomingChatMessages').append($('<li></li>').text($('#outgoingChatMessage').val()));
$('#outgoingChatMessage').val('');
}
});
});
Server Side
var fs = require('fs'), http = require('http'), socketio = require('socket.io');
var server = http.createServer(function(req, res) {
res.writeHead(200, { 'Content-type': 'text/html'});
res.end(fs.readFileSync(__dirname + '/index.html'));
}).listen(8080, function() {
console.log('Listening at: localhost');
});
socketio.listen(server).on('connection', function (socket) {
socket.on('message', function (msg) {
console.log('Message Received: ', msg);
socket.broadcast.emit('message', msg);
});
});
Question :
How can I include the getUserMedia and other WEBRTC API's to create a simple video application ?
Have you looked at, or found, an opensource code set named webrtc.io. If you look at the example code (in the webrtc.io-demo project), you will find a really good example of how to use the getusermedia and peerconnection API's. This code does implement node.js but websocket.io instead of socket.io. I do not know that much about either, so I am not sure if there exists any compatibility between them.

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