Node.js HTTP Module

The Built-in HTTP Module

Node.js includes a powerful built - in HTTP module that enables you to create HTTP servers and make HTTP requests.

Key Features

Make HTTP requests to other servers

Handle different HTTP methods (GET, POST, PUT, DELETE, etc.)

Work with request and response headers

Handle streaming data for large payloads

Including the HTTP Module

const http = require('http');

// Or using ES modules (Node.js 14 + with "type": "module" in package.json)

// import http from 'http';

Creating an HTTP Server

The HTTP module's createServer()

Basic HTTP Server Example

// Import the HTTP module const http = require('http');
// Create a server object const server = http.createServer((req, res) => {

// Set the response HTTP header with HTTP status and Content type res.writeHead(200, { 'Content - Type': 'text/plain' });

res.end('Hello, World!\n');
});
// Define the port to listen on const PORT = 3000;
// Start the server and listen on the specified port server.listen(PORT, 'localhost', () => {
console.log(`Server running at http://localhost:${PORT}/`);
});
Understanding the Code http.createServer()

Running the Server

Working with HTTP Headers

HTTP headers let you send additional information with your response.
The res.writeHead()

Setting Response Headers

const server = http.createServer((req, res) => {
// Set status code and multiple headers res.writeHead(200, {

'Content - Type': 'text/html',
'X - Powered - By': 'Node.js',
'Cache - Control': 'no - cache, no - store, must - revalidate',

'Set-Cookie': 'sessionid=abc123; HttpOnly'
});
res.end('<h1>Hello, World!</h1>');
});
server.listen(3000, () => {
console.log('Server running at http://localhost:3000/');
});

Common HTTP Status Codes

Code

Message

Description

Standard response for successful HTTP requests

Created

Moved Permanently

Bad Request

Unauthorized

Authentication is required

Forbidden

Server refuses to authorize the request