go web: 4 处理默认错误

src--|
     handlers--|
               test--|
                     test.go
     logger--|
             logger.go
     |
     main.go

// myHost 做中间件和Handler全局错误使用。免得一个panic把全局挂挂
func myHost(handler http.Handler) http.Handler {
    ourFunc := func(w http.ResponseWriter, r *http.Request) {
        var err error
        defer func() {
            rec := recover()
            if rec != nil {
                switch t := rec.(type) {
                case string:
                    err = errors.New(t)
                case error:
                    err = t
                default:
                    err = errors.New("Unknown error")
                }
                http.Error(w, err.Error(), http.StatusInternalServerError)
                logger.Errorln(
                    fmt.Sprintf("%s %s \n %s", r.Method, r.URL, err.Error()))
            }
        }()
        //记录时间
        start := time.Now()
        handler.ServeHTTP(w, r)
        logger.Infoln(
            fmt.Sprintf("%s %s %s", r.Method, r.URL, time.Now().Sub(start)))

    }
    return http.HandlerFunc(ourFunc)
}