Node.js Http2ServerResponse.writeHead() Method
The Http2ServerResponse.writeHead() is an inbuilt application programming interface of the class Http2ServerResponse within the http2 module which is used to send the response header to the request.
Syntax:
response.writeHead(statusCode[, statusMessage][, headers])
Parameters: This method accepts the following argument as a parameter.
- statusCode: It is the 3-digit HTTP status code.
- statusMessage: It is a human-readable status message. It is an optional parameter.
- headers: This is the response header passed as a parameter. It is an optional parameter.
Return Value: This method has nothing to return.
How to generate a Private key and Public certificate?
1. Filename: Private key
Open notepad and copy-paste the following key and save the file as private-key.pem
-----BEGIN RSA PRIVATE KEY----- MIICXQIBAAKBgQC38R9wXcUbhOd44FavgmE5R3K4JeYOHLnI7dUq1B8/Gv7l3SOg JKef/m9gM1KvUx951mapXGtcWgwB08J3vUE2YOZ4tWJArrVZES0BI/RmFAyhQFP5 HcWl3LSM9LRihP98F33oIkKaCxA5LxOrkgpV4HrUzIKTABDYah7RPex1WQIDAQAB AoGBAIXR71xxa9gUfc5L7+TqBs+EMmrUb6Vusp8CoGXzQvRHMJCMrMFySV0131Nu o0YYRDsAh1nJefYLMNcXd1BjqI+qY8IeRsxaY+9CB2KKGVVDO2uLdurdC2ZdlWXT Vwr3dDoyR0trnXJMmH2ijTeO6bush8HuXxvxJBjvEllM5QYxAkEA3jwny9JP+RFu 0rkqPBe/wi5pXpPl7PUtdNAGrh6S5958wUoR4f9bvwmTBv1nQzExKWu4EIp+7vjJ fBeRZhnBvQJBANPjjge8418PS9zAFyKlITq6cxmM4gOWeveQZwXVNvav0NH+OKdQ sZnnDiG26JWmnD/B8Audu97LcxjxcWI8Jc0CQEYA5PhLU229lA9EzI0JXhoozIBC TlcKFDuLm88VSmlHqDyqvF9YNOpEdc/p2rFLuZS2ndB4D+vu6mjwc5iZ3HECQCxy GBHRclQ3Ti9w76lpv+2kvI4IekRMZWDWnnWfwta+DGxwCgw2pfpleBZkWqdBepb5 JFQbcxQJ0wvRYXo8qaUCQQCgTvWswBj6OTP7LTvBlU1teAN2Lnrk/N5AYHZIXW6m nUG9lYvH7DztWDTioXMrruPF7bdXfZOVJD8t0I4OUzvC -----END RSA PRIVATE KEY-----
2. Filename: Public certificate
Open notepad and copy-paste the following key and save the file as public-cert.pem
-----BEGIN CERTIFICATE----- MIICfzCCAegCCQDxxeXw914Y2DANBgkqhkiG9w0BAQsFADCBgzELMAkGA1UEBhMC SU4xEzARBgNVBAgMCldlc3RiZW5nYWwxEDAOBgNVBAcMB0tvbGthdGExFDASBgNV BAoMC1BhbmNvLCBJbmMuMRUwEwYDVQQDDAxSb2hpdCBQcmFzYWQxIDAeBgkqhkiG 9w0BCQEWEXJvZm9mb2ZAZ21haWwuY29tMB4XDTIwMDkwOTA1NTExN1oXDTIwMTAw OTA1NTExN1owgYMxCzAJBgNVBAYTAklOMRMwEQYDVQQIDApXZXN0YmVuZ2FsMRAw DgYDVQQHDAdLb2xrYXRhMRQwEgYDVQQKDAtQYW5jbywgSW5jLjEVMBMGA1UEAwwM Um9oaXQgUHJhc2FkMSAwHgYJKoZIhvcNAQkBFhFyb2ZvZm9mQGdtYWlsLmNvbTCB nzANBgkqhkiG9w0BAQEFAAOBjQAwgYkCgYEAt/EfcF3FG4TneOBWr4JhOUdyuCXm Dhy5yO3VKtQfPxr+5d0joCSnn/5vYDNSr1MfedZmqVxrXFoMAdPCd71BNmDmeLVi QK61WREtASP0ZhQMoUBT+R3Fpdy0jPS0YoT/fBd96CJCmgsQOS8Tq5IKVeB61MyC kwAQ2Goe0T3sdVkCAwEAATANBgkqhkiG9w0BAQsFAAOBgQATe6ixdAjoV7BSHgRX bXM2+IZLq8kq3s7ck0EZrRVhsivutcaZwDXRCCinB+OlPedbzXwNZGvVX0nwPYHG BfiXwdiuZeVJ88ni6Fm6RhoPtu2QF1UExfBvSXuMBgR+evp+e3QadNpGx6Ppl1aC hWF6W2H9+MAlU7yvtmCQQuZmfQ== -----END CERTIFICATE-----
Example 1: Filename: index.js
Javascript
// Node.js program to demonstrate the // Http2ServerResponse.writeHead() method const http2 = require( 'http2' ); const fs = require( 'fs' ); // Private key and public certificate for access const options = { key: fs.readFileSync( 'private-key.pem' ), cert: fs.readFileSync( 'public-cert.pem' ), }; // Request and response handler const http2Handlers = (request, response) => { // Sending the data to the client // by using response.writeHead() method response.writeHead(200, { 'Content-Length' : Buffer.byteLength( 'hello world' ), 'Content-Type' : 'text/plain; charset=utf-8' }); // Sending the signal to the client response.end( "hello world" ) }; // Creating and initializing server // by using http2.createServer() method const server = http2.createServer(options, http2Handlers); server.on( 'stream' , (stream, requestheader) => { stream.write( 'hello ' ); // Getting all information of this http2stream object // by using state method const status = stream.state; stream.end( "priority weight : " + status.weight); // Stopping the server // by using the close() method server.close(() => { console.log( "server destroyed" ); }) }); server.listen(8000); // Creating and initializing client // by using tls.connect() method const client = http2.connect( 'http://localhost:8000' ); const req = client.request({ ':method' : 'GET' , ':path' : '/' }); req.on( 'response' , (responsesocket) => { console.log(responsesocket); }); req.on( 'data' , (data) => { console.log( 'Received: %s ' , data.toString().replace(/(\n)/gm, "" )); }); req.on( 'end' , () => { client.close(() => { console.log( "client destroyed" ); }) }); |
Run the index.js file using the following command:
node index.js
Output:
[Object: null prototype] { ':status': 200, 'content-length': '11', 'content-type': 'text/plain; charset=utf-8', date: 'Sun, 06 Dec 2020 14:12:00 GMT' } Received: hello world client destroyed server destroyed
Example 2: Filename: index.js
Javascript
// Node.js program to demonstrate the // Http2ServerResponse.writeHead() method const http2 = require( 'http2' ); const fs = require( 'fs' ); // Private key and public certificate for access const options = { key: fs.readFileSync( 'private-key.pem' ), cert: fs.readFileSync( 'public-cert.pem' ), }; // Request and response handler const http2Handlers = (request, response) => { // Sending the data to the client // by using response.writeHead() method response.writeHead(200, { 'Content-Length' : Buffer.byteLength( 'hello world' ), 'Content-Type' : 'text/plain; charset=utf-8' }); // Sending the signal to client response.end( "hello world" ) }; // Creating and initializing server // by using http2.createServer() method const server = http2.createServer( options, http2Handlers); server.on( 'stream' , (stream, requestheader) => { // Stopping the server // by using the close() method server.close(() => { console.log( "server destroyed" ); }) }); server.listen(8000); // Creating and initializing client // by using tls.connect() method const client = http2.connect( 'http://localhost:8000' ); const req = client.request({ ':method' : 'GET' , ':path' : '/' }); req.on( 'response' , (responsesocket) => { console.log(responsesocket); }); req.on( 'end' , () => { client.close(() => { console.log( "client destroyed" ); }) }); |
Run the index.js file using the following command:
node index.js
Output:
[Object: null prototype] { ':status': 200, 'content-length': '11', 'content-type': 'text/plain; charset=utf-8', date: 'Sun, 06 Dec 2020 14:39:31 GMT' }
Reference:
https://nodejs.org/dist/latest-v12.x/docs/api/http2.html#http2_response_writehead_statuscode_statusmessage_headers