package main import ( "fmt" "log" "net/http" ) var v string = "v1.0" type Middleware struct { Name string } func (m *Middleware) Handler(w http.ResponseWriter, r *http.Request) { //println("Hello") log.Println(r.Header.Get("User-Agent")) w.Header().Set("test", "ok") log.Println(w.Header()) fmt.Fprintln(w, "Welcome to my website", m.Name) } func main() { m := &Middleware{"Test"} http.HandleFunc("/", m.Handler) http.ListenAndServe(":8080", nil) }