浅谈Golang中创建一个简单的服务器的方法

func sayHi(w http.ResponseWriter, r *http.Request) {
  fmt.Fprint(w,"Hi")
}

func main() {
  http.HandleFunc("/sayHi", sayHi)
  log.Fatal(http.ListenAndServe("localhost:8080", nil))
}

func sayHi(w http.ResponseWriter, r *http.Request) {
  fmt.Fprint(w,"Hi")
}

func main() {
  serveMux := http.DefaultServeMux
  serveMux.HandleFunc("/sayHi", sayHi)
  log.Fatal(http.ListenAndServe("localhost:8080", serveMux))
}

func HandleFunc(pattern string, handler func(ResponseWriter, *Request)) {
  DefaultServeMux.HandleFunc(pattern, handler)
}

func (mux *ServeMux) HandleFunc(pattern string, handler func(ResponseWriter, *Request)) {
  mux.Handle(pattern, HandlerFunc(handler))
}

func (mux *ServeMux) Handle(pattern string, handler Handler) {
  mux.mu.Lock()
  defer mux.mu.Unlock()

  if pattern == "" {
    panic("http: invalid pattern")
  }
  if handler == nil {
    panic("http: nil handler")
  }
  if _, exist := mux.m[pattern]; exist {
    panic("http: multiple registrations for " + pattern)
  }

  if mux.m == nil {
    mux.m = make(map[string]muxEntry)
  }
  mux.m[pattern] = muxEntry{h: handler, pattern: pattern}

  if pattern[0] != '/' {
    mux.hosts = true
  }
}

serveMux := http.DefaultServeMux
serveMux.HandleFunc("/sayHi", sayHi)

func ListenAndServe(addr string, handler Handler) error {
  server := &Server{Addr: addr, Handler: handler}
  return server.ListenAndServe()
}

go c.serve(ctx)

serverHandler{c.server}.ServeHTTP(w, w.req)

if handler == nil {
    handler = DefaultServeMux
  }
...
handler.ServeHTTP(rw, req)