How to build a nodejs project

Build a Node.js project

With the popularity of Node.js, more and more developers are paying attention to this JavaScript runtime. Many people want to know how to set up a Node.js project. This article will introduce how to build a Node.js project and introduce some useful tools and techniques.

1. Install Node.js

First make sure you have installed Node.js. You can download the Node.js installer from the Node.js official website (https://nodejs.org) and follow the wizard to install it.

After the installation is completed, you can open the terminal (Windows system can open cmd through the "run" command) and enter the "node -v" command to test whether Node.js has been successfully installed. If the installation is successful, the version number of Node.js will be output.

2. Choose an IDE

The next step is to choose a development tool (IDE) to write Node.js code. Commonly used Node.js development tools include Visual Studio Code, Sublime Text, Atom, WebStorm, etc.

In this article, we will use Visual Studio Code for development.

3. Create a new project

Open Visual Studio Code, select "Open Folder", then create a new folder and name it "myapp".

Create a new folder in the folder and name it "public". This will be where we store static files, such as JavaScript and CSS files.

Next create a new file under the "myapp" folder and name it "app.js". This will be the entry point file for our Node.js application.

4. Write code in app.js

Open "app.js" and enter the following code:

const http = require('http');
const fs = require('fs');
const path = require('path');

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

const server = http.createServer((req, res) => {
  console.log(`Request for ${req.url} received.`);

  let filePath = '.' + req.url;
  if (filePath == './') {
    filePath = './public/index.html';
  }

  const extname = String(path.extname(filePath)).toLowerCase();
  const mimeTypes = {
    '.html': 'text/html',
    '.js': 'text/javascript',
    '.css': 'text/css',
    '.json': 'application/json',
    '.png': 'image/png',
    '.jpg': 'image/jpg',
    '.gif': 'image/gif',
    '.svg': 'image/svg+xml',
    '.wav': 'audio/wav',
    '.mp4': 'video/mp4',
    '.woff': 'application/font-woff',
    '.ttf': 'application/font-ttf',
    '.eot': 'application/vnd.ms-fontobject',
    '.otf': 'application/font-otf',
    '.wasm': 'application/wasm'
  };

  const contentType = mimeTypes[extname] || 'application/octet-stream';

  fs.readFile(filePath, (err, content) => {
    if (err) {
      if (err.code == 'ENOENT') {
        res.writeHead(404, { 'Content-Type': 'text/html' });
        res.end(`<h1>404 Not Found</h1><p>The requested URL ${req.url} was not found on this server.</p>`);
      } else {
        res.writeHead(500, { 'Content-Type': 'text/html' });
        res.end(`<h1>500 Internal Server Error</h1><p>Sorry, we couldn't process your request. Please try again later.</p>`);
      }
    } else {
      res.writeHead(200, { 'Content-Type': contentType });
      res.end(content, 'utf-8');
    }
  });
});

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

This code snippet creates an HTTP server and The request is matched against the corresponding file. For example, if "/about.html" is requested, the server will look for the about.html file in the myapp/public folder and return it. If the request does not match a file, a 404 error is returned.

5. Add routing

We can extend the application by adding routing. Here we will add a simple route to handle GET requests to the "/hello" path.

Add the following code to the end of the app.js file:

server.on('request', (req, res) => {
  if (req.method === 'GET' && req.url === '/hello') {
    res.writeHead(200, { 'Content-Type': 'text/plain' });
    res.end('Hello, world!\n');
  }
});

This code snippet listens for requests and returns a simple " Hello, world!" string.

6. Run the application

Now that we have completed the development of the Node.js application, we need to run the application. Enter the following command in the terminal:

node app.js

This will start the application and bind it to port 3000.

Now, entering "http://localhost:3000/" in the browser will open our static web page. And entering "http://localhost:3000/hello" will return the "Hello, world!" string.

7. Summary

Node.js is a very popular JavaScript runtime that can help developers quickly build highly scalable applications. By using the tips and tools introduced in this article, you can easily build a Node.js application.

I hope this article can be helpful to you, and I wish you success in building your own Node.js project!

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