How to Create a Simple http Web Server Using Node.js

Node.js is a powerful platform for building scalable network applications. In this tutorial, we’ll walk through the steps to create your first web server using Node.js. By the end, you will have a basic understanding of how to set up a server, handle requests, and send responses.

Prerequisites

Before we start, ensure you have the following:

1. Node.js installed: You can download it from nodejs.org.
2. A code editor (like Visual Studio Code, Atom, or Sublime Text).
3. Basic knowledge of JavaScript.

Step 1: Create a New Project

First, let’s create a new directory for our project. Open your terminal and run the following commands:

mkdir my-node-server
cd my-node-server
npm init -y

This will create a new directory and initialize a new Node.js project with a package.json file.

Step 2: Create the Server File

Next, create a file named server.js in your project directory:

touch server.js

Open server.js in your code editor, and let’s start coding our server!

Step 3: Write the Server Code

Add the following code to server.js:

// Import the built-in http module
const http = require('http');

// Define the hostname and port
const hostname = '127.0.0.1'; // localhost
const port = 3000; // You can choose any available port

// Create the server
const server = http.createServer((req, res) => {
    res.statusCode = 200; // Set the response status code to 200 (OK)
    res.setHeader('Content-Type', 'text/html'); // Set the content type
    res.end('<h1>Hello, World!</h1><p>This is my first Node.js server!</p>'); // Send the response
});

// Make the server listen on the specified port
server.listen(port, hostname, () => {
    console.log(`Server running at http://${hostname}:${port}/`);
});

Explanation of the Code:

1. Import the HTTP Module: We use Node.js’s built-in http module to create an HTTP server.
2. Define Hostname and Port: Here, we set the hostname to localhost and the port to 3000. You can change the port if needed.
3. Create the Server: We use http.createServer() to create a new server that listens for incoming requests.
4. Send a Response: Inside the server callback, we set the response status and content type, and send a simple HTML response.
5. Start the Server: Finally, we make the server listen on the specified hostname and port.

Step 4: Run Your Server

Go back to your terminal and run the following command to start your server:

node server.js

You should see the following output:

Server running at http://127.0.0.1:3000/

Step 5: Access Your Server

Open your web browser and navigate to http://127.0.0.1:3000/. You should see a page displaying:

Hello, World!
This is my first Node.js server!

Congratulations! You have successfully built your first web server with Node.js.

Step 6: Adding Routing

Now that you have a basic server, let’s add some routing to handle different requests. Update your server.js file with the following code:

const http = require('http');

const hostname = '127.0.0.1';
const port = 3000;

const server = http.createServer((req, res) => {
    if (req.url === '/') {
        res.statusCode = 200;
        res.setHeader('Content-Type', 'text/html');
        res.end('<h1>Home Page</h1><p>Welcome to the home page!</p>');
    } else if (req.url === '/about') {
        res.statusCode = 200;
        res.setHeader('Content-Type', 'text/html');
        res.end('<h1>About Page</h1><p>This is the about page!</p>');
    } else {
        res.statusCode = 404;
        res.setHeader('Content-Type', 'text/html');
        res.end('<h1>404 Not Found</h1><p>The page you are looking for does not exist.</p>');
    }
});

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

Explanation of the Routing Code:

• We check the req.url property to determine which page the user is trying to access.
• Depending on the URL (either / or /about), we send different HTML responses.
• If the URL does not match any of our defined routes, we return a 404 Not Found response.

Step 7: Test the Routes

1. Refresh your browser at http://127.0.0.1:3000/ to see the home page.
2. Go to http://127.0.0.1:3000/about to see the about page.
3. Try accessing a non-existent page (e.g., http://127.0.0.1:3000/unknown) to see the 404 error page.

Conclusion

In this tutorial, you’ve learned how to build a basic web server using Node.js. You created a server, handled requests, and implemented routing to respond to different URLs.

Node.js is a powerful tool for developing server-side applications, and this is just the beginning. As you grow more comfortable with Node.js, you can explore frameworks like Express.js to build more complex applications with ease.