Node.js http.server.listening Property
Last Updated : 05 Apr, 2023
The http.server.listening is an inbuilt application programming interface of class Server within http module which is used to check if the server is listening for connection or not.
Syntax:
const server.listening
Parameters: It does not accept any argument as a parameter.
Return Value: It does not return any value.
Example 1: Filename: index.js
JavaScript // Node.js program to demonstrate the // server.listening APi // Importing http module const http = require('http'); // Setting up PORT const PORT = process.env.PORT || 3000; // Creating http Server const httpServer = http.createServer( function (request, response) { // getting the reference of the // underlying socket object // by using socket API const value = response.socket; // display result // by using end() api response.end("socket buffersize : " + value.bufferSize, 'utf8', () => { console.log("displaying the result..."); // closing server // by using close() api httpServer.close(() => { console.log("server is closed") }) }); }); // Listening to http Server // by using listen() api httpServer.listen(PORT, () => { console.log("Server is running at port 3000..."); }); // checking if the server is listening or not if (httpServer.listening) console.log("server is listening") else console.log("server is not listening") Output:
Output: In-Console
server is listening Server is running at port 3000... displaying the result... displaying the result... server is closed server is closed
Now run http://localhost:3000/ in the browser.
Output: In-Browser
socket buffersize : 0
Example 2: Filename: index.js
JavaScript // Node.js program to demonstrate the // server.listening APi // Importing http module const http = require('http'); // Request and response handler const http2Handlers = (request, response) => { // getting the reference of the // underlying socket object // by using socket API const value = response.socket; // display result // by using end() api response.end("socket local address : " + value.localAddress, 'utf8', () => { console.log("displaying the result..."); // closing server // by using close() api httpServer.close(() => { console.log("server is closed") }) }); }; // Listening to http Server // by using listen() api const httpServer = http.createServer( http2Handlers).listen(3000, () => { console.log("Server is running at port 3000..."); }); // checking if the server is listening or not if (httpServer.listening) console.log("server is listening") else console.log("server is not listening") Output:
Output: In-Console
server is listening Server is running at port 3000... displaying the result... displaying the result... server is closed server is closed
Now run http://localhost:3000/ in the browser.
Output: In-Browser
socket local address : ::1
Reference: https://nodejs.org/dist/latest-v12.x/docs/api/http.html#http_server_listening
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