Node.js Http2ServerResponse.hasHeader() Method
The Http2ServerResponse.hasHeader() is an inbuilt application programming interface of the class Http2ServerResponse within the http2 module which is used to check if the header identified by name is currently set in the outgoing headers or not.
Syntax:
response.hasHeader(name)
Parameters: This method accepts the name of the header as the parameter.
Return Value: This method returns true if and only if the header identified by name is currently set in the outgoing headers or not.
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.hasHeader() 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) => { // Setting new header response.setHeader( 'Content-Type' , 'hello world; charset=utf-8' ); // Checking if the header is present or not // by using hasHeader() method const value = response.hasHeader( 'Content-Type' ) // Display the header if (value) console.log( "header is present" ) else console.log( "header is not present" ) }; // 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( "status : " + responsesocket[ ":status" ]); }); 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:
header is present status : 200 Received: hello Received: priority weight : 16 client destroyed server destroyed
Example 2: Filename: index.js
Javascript
// Node.js program to demonstrate the // Http2ServerResponse.hasHeader() 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) => { // Setting new header response.setHeader( 'Foo' , 'bar' ); response.setHeader( 'Set-Cookie' , [ 'foo=bar' , 'bar=baz' ]); // Checking if the header is present or not // by using hasHeader() method const value = response.hasHeader( 'Content-Type' ) // Display the header if (value) console.log( "header is present" ) else console.log( "header is not present" ) }; // Creating and initializing server // by using http2.createServer() method const server = http2.createServer(options, http2Handlers); server.on( 'stream' , (stream, requestHeaders) => { // Getting all information of this http2stream object // by using state method const status = stream.state; stream.end( "The sum weight of all Http2Stream : " + status.sumDependencyWeight); // 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' : '/www.w3wiki.net' }); 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:
header is not present Received: The sum weight of all Http2Stream : 0 client destroyed server destroyed
Reference: https://nodejs.org/dist/latest-v12.x/docs/api/http2.html#http2_response_hasheader_name