扩展HTTP处理程序

感谢＃go-nuts上的“
cronos”帮助，我设法解决了这一问题。

该解决方案允许我使用自定义处理程序类型，链中间件，并避免重复包装处理程序（即appHandler（myHandler），中间件…）：

type appHandler func(http.ResponseWriter, *http.Request) *appErrortype appError struct {    Code  int    Error error}func (fn appHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {    if e := fn(w, r); e != nil {        switch e.Code {        case http.StatusNotFound: notFound(w, r)        case http.StatusInternalServerError: serverError(w, r, e.Error, e.Code)        default: serverError(w, r, e.Error, e.Code)        }    }}func use(h appHandler, middleware ...func(http.Handler) http.Handler) http.Handler {    var res http.Handler = h    for _, m := range middleware {        res = m(res)    }    return res}func someMiddleware(h http.Handler) http.Handler {    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {        w.Header().Set("Cache-Control", "max-age=0, private, must-revalidate")        w.Header().Set("X-Accel-Expires", "0")        h.ServeHTTP(w, r)    })}func myHandler(w http.ResponseWriter, r *http.Request) *appError {    err := doSomething()    if err != nil {        return &appError{500, err}    }    // render your template, etc.    return nil}

路线如下所示：

r.Handle("/route", use(myHandler, someMiddleware))

您显然可以进行修改

appHandler

appError

http.Handle("/",someMiddleware(r))