func proxyHandler(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
u, _ := url.Parse("http://127.0.0.1:9000/")
proxy := httputil.NewSingleHostReverseProxy(u)
proxy.ServeHTTP(w, r)
}
原文：https://www.cnblogs.com/thotf/p/12731763.html