node.js /socket.io/socket.io.js not found

问题:

i keep on getting the error /socket.io/socket.io.js 404 (Not Found) Uncaught ReferenceError: io is not defined

my code is

var express = require('express'), http = require('http');
var app = express();
var server = http.createServer(app);
var io = require('socket.io').listen(server);

server.listen(3000);

and

<script src="/socket.io/socket.io.js"></script>

what is the problem ???

any help is welcome!

回答1:

Copying socket.io.js to a public folder (something as resources/js/socket.io.js) is not the proper way to do it.

If Socket.io server listens properly to your HTTP server, it will automatically serve the client file to via http://localhost:<port>/socket.io/socket.io.js, you don't need to find it or copy in a publicly accessible folder as resources/js/socket.io.js & serve it manually.

Code sample
Express 3.x - Express 3 requires that you instantiate a http.Server to attach socket.io to first

var express = require('express')
  , http = require('http');
//make sure you keep this order
var app = express();
var server = http.createServer(app);
var io = require('socket.io').listen(server);

//... 

server.listen(8000);

Happy Coding :)

回答2:

How to find socket.io.js for client side

install socket.io

npm install socket.io

find socket.io client

find ./ | grep client | grep socket.io.js

result:

./node_modules/socket.io/node_modules/socket.io-client/dist/socket.io.js

copy socket.io.js to your resources:

cp ./node_modules/socket.io/node_modules/socket.io-client/dist/socket.io.js /home/proyects/example/resources/js/

in your html:

<script type="text/javascript" src="resources/js/socket.io.js"></script>

回答3:

It seems that this question may have never been answered (although it may be too late for the OP, I'll answer it for anyone who comes across it in the future and needs to solve the problem).

Instead of doing npm install socket.io you have to do npm install socket.io --save so the socket.io module gets installed in your web development folder (run this command at the base location/where your index.html or index.php is). This installs socket.io to the area in which the command is run, not globally, and, in addition, it automatically corrects/updates your package.json file so node.js knows that it is there.

Then change your source path from '/socket.io/socket.io.js' to 'http://' + location.hostname + ':3000/socket.io/socket.io.js'.

回答4:

... "You might be wondering where the /socket.io/socket.io.js file comes from, since we neither add it and nor does it exist on the filesystem. This is part of the magic done by io.listen on the server. It creates a handler on the server to serve the socket.io.js script file."

from the book Socket.IO Real-time Web Application Development, page 56

回答5:

while this doesn't have anything to do with the OP, if you're running across this issue while maintaining someone else's code, you might find that the problem is caused by the coder setting io.set('resource', '/api/socket.io'); in the application script, in which case your HTML code would be <script>type="text/javascript" src="/api/socket.io/socket.io.js"></script>.

回答6:

You must just follow https://socket.io/get-started/chat/ and all will work.

var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);
http.listen(3000, function(){
  console.log('listening on *:3000');
});