function - 类型如何间接引用其他函数基方法？

Question

首先，我仍然不清楚如何提出这个问题，但我无法理解，有人可以帮助我理解这一点。如果我重命名“serveHTTP”或没有该方法，为什么下面的代码会出错。

prog.go:17: cannot use &status (type *statusHandler) as type http.Handler in argument to httptest.NewServer:
*statusHandler does not implement http.Handler (missing ServeHTTP method)
[process exited with non-zero status]

对于下面的代码

type statusHandler int

func (s *statusHandler) aServeHTTP(w http.ResponseWriter, r *http.Request) {
    log.Println(" inside status handler serve http")
}

func main() {
    status := statusHandler(400)
    s := httptest.NewServer(&status)
    log.Println("value of s is %d", s)
    defer s.Close()
}

http://play.golang.org/p/QZIrWALAm_

Answer 1

ServeHTTP 需要满足 http.Handler界面。

type Handler interface {
        ServeHTTP(ResponseWriter, *Request)
}

Interfaces in Go provide a way to specify the behavior of an object: if something can do this, then it can be used here.

参见 Interfaces and Types in Effective Go了解更多信息。