go的http包

type Handler interface {    ServeHTTP(ResponseWriter, *Request)}type HandlerFunc func(ResponseWriter, *Request)  HandlerFunc为特定函数类型

The HandlerFunc type is an adapter to allow the use of ordinary functions as HTTP handlers.

 If f is a function with the appropriate signature, HandlerFunc(f) is a Handler that calls f.

func (f HandlerFunc) ServeHTTP(w ResponseWriter, r *Request)ServeHTTP calls f(w, r).  ServeHTTP调用该方法