最近日志打印的时候需要打印状态码，但是因为interface的原因直接获取失败，http.Request里面的response不知道怎么使用，所以就自己重写writeheader，write来截取status
type doneWriter struct {
http.ResponseWriter
done bool
status int
}
func (w *doneWriter) WriteHeader(status int) {
w.done = true
w.status= status
w.ResponseWriter.WriteHeader(status)
}
func (w *doneWriter) Write(b []byte) (int, error) {
w.done = true
return w.ResponseWriter.Write(b)
}
func myMiddleware(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
dw := &doneWriter{ResponseWriter: w}
next.ServeHTTP(dw, r)
if dw.done {
// Something already wrote a response
return
}
// Nothing else wrote a response
w.WriteHeader(http.StatusOK)
// Whatever you want here
}
}