golang实现http server提供文件下载功能

golang实现http server提供文件下载功能

func FileDownload(w http.ResponseWriter, r *http.Request) {
    filename := get_filename_from_request(r)

    file, _ := os.Open(filename)
    defer file.Close()

    fileHeader := make([]byte, 512)
    file.Read(fileHeader)

    fileStat, _ := file.Stat()

    w.Header().Set("Content-Disposition", "attachment; filename=" + filename)
    w.Header().Set("Content-Type", http.DetectContentType(fileHeader))
    w.Header().Set("Content-Length", strconv.FormatInt(fileStat.Size(), 10))

    file.Seek(0, 0)
    io.Copy(w, file)

    return
}