node.js web server module

What is web server ?

Web servers can refer to hardware or software or both of them working together.

Web servers are computers that are usually setup in facilities called Data Centers and operated by hosting companies.The files stored on web servers are read by browsers.Browsers communicates with web servers to bring you information from internet.

Purpose of Web server

• Store website so that people can visit them on internet.
• It serves file as per request.
• It can send same or different file to one or more than one user at the same time.

Today I am discussing a small node.js application probably you are familiar with this example but it is mandatory to create a base.During this example I will discuss about starting a web server using node js.In node js one thing is very interesting that you need not install any other setup like Apache Tomcat or any other for node js application.You can run your application with node js setup that you have already install during your first "Hello World" console application.

Now our level has gone high and today we are discussing our first "Hello World" web application.

for this purpose I have to create two files

1. index.html : which display on browser after server is started.
2. server.js : before running our first application on browser server should be started and that will be done by server.js.

At first we create a sever and for that purpose we have write following code .

var http = require('http');  
var fs = require('fs');  
var url = require('url');  
  
// Create a server  
http.createServer( function (request, response) {    
   // Parse the request containing file name  
   var pathname = url.parse(request.url).pathname;  
     
   // Print the name of the file for which request is made.  
   console.log("Request for " + pathname + " received.");  
     
   // Read the requested file content from file system  
   fs.readFile(pathname.substr(1), function (err, data) {  
      if (err) {  
         console.log(err);  
         // HTTP Status: 404 : NOT FOUND  
         // Content Type: text/plain  
         response.writeHead(404, {'Content-Type': 'text/html'});  
      }else{      
         //Page found       
         // HTTP Status: 200 : OK  
         // Content Type: text/plain  
         response.writeHead(200, {'Content-Type': 'text/html'});      
           
         // Write the content of the file to response body  
         response.write(data.toString());         
      }  
      // Send the response body   
      response.end();  
   });     
}).listen(8081);  
// Console will print the message  
console.log('Server running at http://127.0.0.1:8081/'); 

After that open cmd and type command

node server.js

after that create html file write this inside body tag

 
      Hello Word!
  

copy this link and paste inside browser url
http://127.0.0.1:8081/index.html
and you will obtain this output