如何在 golang 中间件中获取响应状态码？

Question

如何在 golang 中间件中获取响应状态码？

ResponseWriter 只有 WriteHeader 接口，我找不到 get 接口。

Answer 1

使用内格罗尼。它的工作原理与 @huangapple 答案相同，但处理程序实际上实现了所有接口。

import (
    "github.com/urfave/negroni"
)

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 := negroni.NewResponseWriter(w)
        wrappedHandler.ServeHTTP(lrw, req)

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

Answer 2

这种方法是可行的。

    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))
        })
    }

Answer 3

长话短说，您应该自己包装 http.ResponseWriter 或使用库。如果你想自己实现，可以从Negroni源代码中找到一些提示