Skip to main content

HTTP Module in Node.js

The HTTP module in Node.js allows you to create an HTTP server that can handle incoming HTTP requests and send HTTP responses. It's a fundamental part of building web applications in Node.js.

Setting Up an HTTP Server​

To get started, you need to import the HTTP module and create an HTTP server. Here's a basic example:

index.js
const http = require('http');

// Create an HTTP server
const server = http.createServer((req, res) => {
  res.writeHead(200, { 'Content-Type': 'text/html' });
  res.end('Hello, World!\n');
});

// Listen on a specific port and host
const port = 3000;
const hostname = 'localhost';
server.listen(port, hostname, () => {
  console.log(`Server running at http://${hostname}:${port}/`);
});

In this example, we import the HTTP module, create a server, and specify a response when someone accesses the server. We then listen on a specific port and host.

http://localhost:3000

Hello, World!

Handling Different HTTP Methods​

HTTP supports various methods like GET, POST, PUT, and DELETE. You can handle these methods in your server. Here's an example of handling GET and POST requests:

index.js
const http = require('http');

const server = http.createServer((req, res) => {
  if (req.method === 'GET') {
    // Handle GET request
    res.writeHead(200, { 'Content-Type': 'text/html' });
    res.end('This is a GET request.\n');
  } else if (req.method === 'POST') {
    // Handle POST request
    let body = '';
    req.on('data', (chunk) => {
      body += chunk;
    });
    req.on('end', () => {
      res.writeHead(200, { 'Content-Type': 'text/html' });
      res.end(`This is a POST request with data: ${body}\n`);
    });
  }
});

const port = 4000;
const hostname = '127.0.0.1';
server.listen(port, hostname, () => {
  console.log(`Server running at http://${hostname}:${port}/`);
});

In this code, we check the request method (GET or POST) and respond accordingly.

Handling URL Paths​

You can also handle different URL paths by parsing the req.url property. Here's an example:

index.js
const http = require('http');

const server = http.createServer((req, res) => {
  const { method, url } = req;
  if (method === 'GET' && url === '/hello') {
    res.writeHead(200, { 'Content-Type': 'text/html' });
    res.end('<p>Hello, Node.js!</p>');
  } else {
    res.writeHead(404, { 'Content-Type': 'text/html' });
    res.end('<p>Not Found</p>');
  }
});

const port = 3000;
const hostname = '127.0.0.1';
server.listen(port, hostname, () => {
  console.log(`Server running at http://${hostname}:${port}/`);
});

Visit http://127.0.0.1:3000/hello in your browser

http://127.0.0.1:3000/hello

Hello, Node.js!

Visit http://127.0.0.1:3000 in your browser

http://127.0.0.1:3000/

Not Found

In this example, we check both the method and the URL path.