dongsi3826 2018-06-05 11:22
浏览 254


I am working on a go project where I need to serve files stored in mongodb. The files are stored in a GridFs. I use as package to connect and query the db.

I can retrieve the file from the db, that is not hard.

f, err := s.files.OpenId(id)

But how can I serve that file with http? I work with the JulienSchmidt router to handle all the other restfull requests. The solutions I find always use static files, not files from a db.

Thanks in advance

  • 写回答

1条回答 默认 最新

  • duanbishai5271 2018-06-05 11:32

    Tip: Recommended to use instead of (the latter is not maintained anymore).

    The mgo.GridFile type implements io.Reader, so you could use io.Copy() to copy its content into the http.ResponseWriter.

    But since mgo.GridFile also implements io.Seeker, you may take advantage of http.ServeContent(). Quoting its doc:

    The main benefit of ServeContent over io.Copy is that it handles Range requests properly, sets the MIME type, and handles If-Match, If-Unmodified-Since, If-None-Match, If-Modified-Since, and If-Range requests.

    Example handler serving a file:

    func serveFromDB(w http.ResponseWriter, r *http.Request) {
        var gridfs *mgo.GridFS // Obtain GridFS via Database.GridFS(prefix)
        name := "somefile.pdf"
        f, err := gridfs.Open(name)
        if err != nil {
            log.Printf("Failed to open %s: %v", name, err)
            http.Error(w, "something went wrong", http.StatusInternalServerError)
        defer f.Close()
        http.ServeContent(w, r, name, time.Now(), f) // Use proper last mod time
    本回答被题主选为最佳回答 , 对您是否有帮助呢?



  • ¥30 关于#c++#的问题,请各位专家解答!
  • ¥15 App的会员连续扣费
  • ¥15 不同数据类型的特征融合应该怎么做
  • ¥15 用proteus软件设计一个基于8086微处理器的简易温度计
  • ¥15 用联想小新14Pro
  • ¥15 multisim中关于74ls192n和DSWPK开关仿真图分析(减法计数器)
  • ¥15 w3wp,exe 中发生未处理的 Microsoft ,NETFramework 异常。
  • ¥20 C51单片机程序及仿真(加减器)
  • ¥15 AQWA | 水动力分析 二阶波浪力
  • ¥15 c语言题目:成绩管理系统