Node.js server without a framework - Learn web development 编辑

This article provides a simple static file server built with pure Node.js without the use of a framework.

Node.js has many frameworks to help you get your server up and running.

The most popular are:

• Express: A widely used framework.
• Hapi.js: A rich framework for building applications and services
• Total: The all-in-one Node.js framework, which does not depend on any other framework, or module.

These will not suit every situation. A developer may need to build their own server without other dependencies.

Example

A simple static file server built with Node.js:

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

http.createServer(function (request, response) {
    console.log('request ', request.url);

    var filePath = '.' + request.url;
    if (filePath == './') {
        filePath = './index.html';
    }

    var extname = String(path.extname(filePath)).toLowerCase();
    var 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'
    };

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

    fs.readFile(filePath, function(error, content) {
        if (error) {
            if(error.code == 'ENOENT') {
                fs.readFile('./404.html', function(error, content) {
                    response.writeHead(404, { 'Content-Type': 'text/html' });
                    response.end(content, 'utf-8');
                });
            }
            else {
                response.writeHead(500);
                response.end('Sorry, check with the site admin for error: '+error.code+' ..\n');
            }
        }
        else {
            response.writeHead(200, { 'Content-Type': contentType });
            response.end(content, 'utf-8');
        }
    });

}).listen(8125);
console.log('Server running at http://127.0.0.1:8125/');

Breakdown

Lines 1 through 3 load modules provided by Node.js, roughly similar to imports.

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

Afterward is the function for creating the server. https.createServer returns a Server object, which we can start up by listening on port 8125.

http.createServer(function (request, response) {
    ...
}).listen(8125);

The following lines deal with fixing the request URL if it does not specify a file.

var filePath = '.' + request.url;
if (filePath == './') {
    filePath = './index.html';
}

For example, if the URL sent is example.org, it will be interpreted as example.org/index.html.

Next, we look for the extension of the file being requested and see if it matches with one of our MIME types. If no matches are found, we use the application/octet-stream as the default type.

var 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'
};

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

Lastly, we respond to the client with the file information. This function reads the file using our previously prepared filePath variable.

fs.readFile(filePath, function(error, content) {
    ...
});

The first thing we do is to compensate for any possible errors. Most often, the error will be ENOENT, in which case we reply with a 404 error.

if(error.code == 'ENOENT') {
    fs.readFile('./404.html', function(error, content) {
        response.writeHead(404, { 'Content-Type': 'text/html' });
        response.end(content, 'utf-8');
    });
}
else {
    response.writeHead(500);
    response.end('Sorry, check with the site admin for error: '+error.code+' ..\n');
}

Finally, if there are no errors, we send over the requested file.

response.writeHead(200, { 'Content-Type': contentType });
response.end(content, 'utf-8');

To do

Perhaps an extended version serving static files and handling dynamic requests.