HapiJS Module: In order to use the hapiJS module, we need to install the NPM (Node Package Manager) and the following modules (on cmd).
// Create package.json file >> npm init // Installs hapi module >> npm install @hapi/hapi --save
Import hapiJS module: Import hapiJS module and store returned instance into a variable.
Syntax:
var Hapi = require("@hapi/hapi");
Creating Server: The above syntax imports the “Hapi” module and now it creates a server. It communicates the request and response with the client and the server. It requires PORT <number> and host <string> to communicate.
Syntax:
const server = Hapi.server({port: 2020, host: 'localhost'});
Parameter: This method accepts three parameters as mentioned above and described below:
- PORT <Number>: Ports are the endpoints of communication that helps to communicate with the client and the server.
- HOST <String>: It accepts the host names like localhost/127.0.0.1, google.com, geeksforgeeks.org, etc.
The below example illustrates the HapiJS module in Node.js.
Example 1: Filename: index.js
// Node.js program to create server // using hapi module // Importing hapi module const Hapi = require( '@hapi/hapi' );
// Creating Server const server = Hapi.server({
port: 2020,
host: 'localhost'
});
// Creating route
server.route({
method: 'GET' ,
path: '/' ,
handler: (request, hnd) => {
return 'Hello GeeksForGeeks!' ;
}
});
const start = async () => { await server.start();
console.log( 'Server running at' , server.info.uri);
}; process.on( 'unhandledRejection' , (err) => {
console.log(err);
process.exit(1);
}); start(); |
Run index.js file using the following command:
node index.js
Output:
Server running at: http://localhost:2020
Now type http://localhost:2020/ in a web browser to see the output.
KoaJS Module: In order to use the KoaJS module, we need to install the NPM (Node Package Manager) and the following modules (on cmd).
// Creates package.json file >> npm init // Installs express module >> npm install koa --save // OR >> npm i koa -s
Import KoaJS module: Import KoaJS module and store returned instance into a variable.
Syntax:
var koa = require("koa"); //importing koa module
Creating Server: The above syntax imports the koa module and creates a new koa application which gets stored inside the app variable.
Syntax:
const app = new koa(); // Creating koa application
Sending and listening to the response: It communicates the request and response with the client and the server. It requires PORT <number> and IP <number> to communicate.
app.listen(PORT, IP, Callback);
Parameter: This method accepts three parameters as mentioned above and described below:
- PORT <Number>: Ports are the endpoints of communication that helps to communicate with the client and the server.
- IP <Number>: IPs represent IPv4 or IPv6 address of a host or a device.
- Callback <Function>: It accepts a function.
The below example illustrates the Koa module in Node.js.
Example 2: Filename: index.js
// Node.js program to create server // with help of Koa module // Importing koa module const koa = require( 'koa' );
// Creating new koa app const app = new koa();
// PORT configuration const PORT = process.env.PORT || 2020; // IP configuration const IP = process.env.IP || 2021; app.use( function *() {
this .body = "Hello GeeksForGeeks!";
}); // Server listening to requests app.listen(PORT, IP, ()=>{ console.log("Server started at port", PORT); }); |
Run index.js file using the following command:
node index.js
Output:
The Server is running at port 2020
Now type http://127.0.0.1:2020/ OR http://localhost:2020/ in a web browser to see the output.