如何在golang中间件中获取Response statusCode？

Question

How do I get Response statusCode in golang middleware?

ResponseWriter have only WriteHeader interface, I can't find get interface.

Answer 1

This method is feasible.

    type loggingResponseWriter struct {
        http.ResponseWriter
        statusCode int
    }

    func NewLoggingResponseWriter(w http.ResponseWriter) *loggingResponseWriter {
        return &loggingResponseWriter{w, http.StatusOK}
    }

    func (lrw *loggingResponseWriter) WriteHeader(code int) {
        lrw.statusCode = code
        lrw.ResponseWriter.WriteHeader(code)
    }

    func wrapHandlerWithLogging(wrappedHandler http.Handler) http.Handler {
        return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
            log.Printf("--> %s %s", req.Method, req.URL.Path)

            lrw := NewLoggingResponseWriter(w)
            wrappedHandler.ServeHTTP(lrw, req)

            statusCode := lrw.statusCode
            log.Printf("<-- %d %s", statusCode, http.StatusText(statusCode))
        })
    }