如果某些权限检查失败，如何提前终止我的处理程序？

Question

我正在寻找一种方法来实现权限检查功能，使用http这个想法是有些API应该只由登录会话使用。func CheckPermissionFilter(w http.ResponseWriter, r *http.Response){    sid, err := r.Cookie("sid")    // check the permission with sid, if permission is granted then just let the     // process go on, otherwise, just break the filter chain and return Http Error Code.}func SomeHttpHandler(w http.ResponseWriter, r *http.Response){     CheckPermissionFilter(w, r)     // if not breaked by above filter function, process the request...   }我对权限检查没有问题，但我找不到破坏HTTP请求处理的方法。

Answer 1

处理程序中的调用不能提前终止后者。相反，您应该定义为中间件（另请参阅装饰器模式）：CheckPermissionFilterSomeHttpHandlerCheckPermissionFilter




package main

import (

    "net/http"

)

func main() {

    http.Handle("/foo", CheckPermissionFilter(SomeHttpHandler))

    // ...

}

func CheckPermissionFilter(h http.HandlerFunc) http.HandlerFunc {

    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {

        sid, err := r.Cookie("sid")

        // handle err

        if !Validate(sid) {

            http.Error(w, "Unauthorized", http.StatusUnauthorized)

            return

        }

        h(w, r)

    })

}

func SomeHttpHandler(w http.ResponseWriter, r *http.Request) {

    // ...

}

func Validate(sid string) bool {

    return true // simplistic implementation for this example

}