http2.go

package main

import (
	"context"
	"crypto/tls"
	"fmt"
	"io"
	"log"
	"net/http"
	"time"
	
	"golang.org/x/net/http2"
)

func main() {
	go startHttp2Server()
	time.Sleep(100 * time.Millisecond)

	if err := startHttp2Client(); err != nil {
		log.Fatalf("Error in HTTP/2 client: %v", err)
	}
}

func startHttp2Server() {
	server := &http.Server{
		Addr:    ":8080",
		Handler: http.HandlerFunc(handle),
		TLSConfig: &tls.Config{
			NextProtos: []string{"h2"}, // Specify HTTP/2 protocol
		},
	}

	log.Println("Starting HTTP/2 server on :8080")
	log.Fatal(server.ListenAndServeTLS("server.crt", "server.key"))
}

func handle(w http.ResponseWriter, r *http.Request) {
	w.WriteHeader(http.StatusOK)
	time.Sleep(time.Second)
	fmt.Fprintf(w, "Hello, HTTP/2 client!")
}

func startHttp2Client() error {
	client := http.Client{
		Transport: &http2.Transport{
			TLSClientConfig: &tls.Config{
				NextProtos:         []string{"h2"},
				InsecureSkipVerify: true,
			},
		},
	}

	ctx, cancel := context.WithCancel(context.Background())
	time.AfterFunc(100*time.Millisecond, cancel)
	req, err := http.NewRequestWithContext(ctx, http.MethodGet, "https://localhost:8080", nil)
	if err != nil {
		return err
	}

	resp, err := client.Do(req)
	if err != nil {
		fmt.Printf("%#v\n", err)
		return err
	}
	defer resp.Body.Close()

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return err
	}

	fmt.Printf("Response from server: %s\n", body)
	return nil
}