node.js: create your first express webserver

In the last tutorial, we have created a simple webserver. That was great as preperation to use the expressframework, which can handle the webserverstuff for us. Let's have a look to express.

Prerequisits

node.js installed
npm installed

Install express globaly

$ npm install -g express

Create a npm project

Create your project rootfolder "express-project" and open a terminal in that folder and typpe:
$ npm init

Follow the intstructions on your terminal.

Add needed dependencies

Open package.json and add your dependencies. My package.json looks like that:

	{
	"name": "simple-express",
	"version": "1.0.0",
	"description": "simple exress sample",
	"main": "app.js",
	"scripts": {
	"test": "echo \"Error: no test specified\" && exit 1"
	},
	"keywords": [
	"exptress"
	],
	"author": "peboethig",
	"license": "MIT",
	"dependencies":
	{
	"node-mailer":"*",
	"body-parser":"*",
	"express":"*",
	"jade":"*"
	}
	}

view raw package hosted with ❤ by GitHub

You can just pick the "dependencies" object 

 

Add you dependencies

Create a file "app.js" and paste following code

	var express = require("express");
	var path = require("path");
	var bodyParser = require("body-parser");
	var nodeMailer = require("'nodemailer");
	var app = express();
	app.use(bodyParser.json());
	app.use(bodyParser.urlencoded({extended:false}));
	app.get("/", function(req, res) {
	console.log("hello world");
	res.send("hello world");
	});
	app.listen(3000, function() {
	console.log("App listening on port 3000!");
	});

view raw app.json hosted with ❤ by GitHub

This will reference your dependencies and setup your express webserver.
As you can see, the webserver will be bound on port 3000 and it will return a simple "Hello world" response and will log the same words to the console.

Start the webserver

Open a terminal in the projectroot and type:
$ node app.js 


Now you can surf http://localhost:3000 and you should see "Hello world"

Thats it