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
// 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
// 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