Golang net/http 后端阻塞请求

有几个选项。第一个是返回一个 error 响应：

func handle(w http.ResponseWriter,r *http.Request) {
    if r.UserAgent() == "test/1.0" {
        //Allow
    } else {
        http.Error(w,"forbidden",http.StatusForbidden)
        return
    }
}

第二种是hijack与服务器的连接并粗暴地关闭连接：

func handle(w http.ResponseWriter,r *http.Request) {
    if r.UserAgent() == "test/1.0" {
        //Allow
    } else {
        if h,ok := w.(http.Hijacker); ok {
            c,_,err := h.Hijack()
            if err != nil {
                c.Close()
                return
            }
        }
        // fallback to error response
        http.Error(w,http.StatusForbidden)
        return
    }
}