Node.js Tutorial - Node.js Web

HTTP Response Codes

The HTTP specification contains a large number of response codes a server can return to clients.

We'll use a few of the more common responses in most of our applications.

200OKEverything went fine.
301Moved PermanentlyThe requested URL has been moved, and the client should rerequest it at the URL specified in the response.
400Bad RequestThe format of the client's request is invalid and needs to be fixed.
401UnauthorizedThe client has asked for something it does not have permission to view.
403ForbiddenThe server is refusing to process this request. This is not the same as 401, where the client can try again with authentication.
404Not FoundThe client has asked for something that does not exist.
500Internal Server ErrorSomething happened resulting in the server being unable to process the request.
503Service UnavailableThis indicates some sort of runtime failure.

Your First JSON Server

Here is the trivial server, which is saved to simple_server.js:

var http = require('http');
// w  w w.j  a  va  2  s.  c om
function  handle_incoming_request (req, res) {
    console.log("INCOMING REQUEST: " + req.method + " " + req.url);
    res.writeHead(200, { "Content-Type" : "application/json" });
    res.end(JSON.stringify( { error: null }) + "\n");

var s = http.createServer(handle_incoming_request);

Run this program in one terminal window (Mac/Linux) or command prompt (Windows) by typing

node simple_server.js

Now, in another terminal window, type

curl -X GET http://localhost:8080

We should see


In the window where you ran the curl command, you should see