Node.js Http2ServerResponse.getHeaders() Method

The Http2ServerResponse.getHeaders() is an inbuilt application programming interface of class Http2ServerResponse within the http2 module which is used to return a shallow copy of the current outgoing headers.

Syntax:

response.getHeaders()

Parameters: This method does not accept any arguments as a parameter.

Return Value: This method returns a shallow copy of the current outgoing headers.

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-----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-----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-----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-----END CERTIFICATE-----

Example 1: Filename: index.js

Javascript

// Node.js program to demonstrate the
// Http2ServerResponse.getHeaders() 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'
  );

  // Getting header's object
  // by using getHeaders() method
  const value = response.getHeaders()

  // Display the header
  console.log(value);
};

// 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:

{ 'content-type': 'hello world; charset=utf-8' }
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.getHeaders() 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']);

    // Getting header's object
    // by using getHeaders() method
    const value = response.getHeaders()

    // Display the header
    console.log(value);
};

// 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.geeksforgeeks.org' });

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:

{ foo: 'bar', 'set-cookie': [ 'foo=bar', 'bar=baz' ] }
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_getheaders