无法使用GOLANG和POLYMER http将上传的文件保存在服务器上:无此文件 [英] Not able to save uploaded file on server using GOLANG and POLYMER http: no such file

问题描述

我正在使用vaadin上传功能，将聚合物上的文件上传到Web应用程序中.而且我正在将golang用于后端.

I am using vaadin upload to upload files on web application with polymer. And I am using golang for back-end.

<vaadin-upload target="../upload" max-files="20" accept="application/pdf,image/*" 
method="POST"> </vaadin-upload>

我检查了vaadin上传中使用的编码类型为 multipart/form-data . 我的golang代码如下.

I checked that encoding type used in vaadin upload is multipart/form-data. My golang code is below.

func upload(w http.ResponseWriter, r *http.Request) {
    fmt.Println("method:", r.Method)
    if r.Method == "GET" {
        crutime := time.Now().Unix()
        h := md5.New()
        io.WriteString(h, strconv.FormatInt(crutime, 10))
        token := fmt.Sprintf("%x", h.Sum(nil))

        t, _ := template.ParseFiles("upload.gtpl")
        t.Execute(w, token)
    } else {
        r.ParseMultipartForm(32 << 20)
        file, handler, err := r.FormFile("uploadFile")
        if err != nil {
            fmt.Println(err)
            return
        }
        defer file.Close()
        fmt.Fprintf(w, "%v", handler.Header)
        f, err := os.OpenFile("./test/"+handler.Filename, os.O_WRONLY|os.O_CREATE, 0666)
        if err != nil {
            fmt.Println(err)
            return
        }
        defer f.Close()
        io.Copy(f, file)
    }
}

它在服务器端 http:没有该文件时出错.当提供的文件字段名称不存在于请求中或文件字段中时，我检查了FormFile返回的此错误.

It gives error on server side http: no such file. I checked this error is returned by FormFile when the provided file field name is either not present in the request or not a file field.

如何更正表单文件名.虽然前端一切都很好

How do I correct my form file name. Although everything seems fine on front-end

推荐答案

为面临相同问题的人解答我自己的问题.找到一些可以在不知道键值的情况下访问文件的代码.

func UploadHandler(res http.ResponseWriter, req *http.Request) {  
      var (  
           status int  
           err  error  
      )  
      defer func() {  
           if nil != err {  
                http.Error(res, err.Error(), status)  
           }  
      }()  
      // parse request  
     // const _24K = (1 << 20) * 24  
      if err = req.ParseMultipartForm(32 << 20); nil != err {  
           status = http.StatusInternalServerError  
           return  
      } 
        fmt.Println("No memory problem")
      for _, fheaders := range req.MultipartForm.File {  
           for _, hdr := range fheaders {  
                // open uploaded  
                var infile multipart.File  
                if infile, err = hdr.Open(); nil != err {  
                     status = http.StatusInternalServerError  
                     return  
                }  
                // open destination  
                var outfile *os.File  
                if outfile, err = os.Create("./uploaded/" + hdr.Filename); nil != err {  
                     status = http.StatusInternalServerError  
                     return  
                }  
                // 32K buffer copy  
                var written int64  
                if written, err = io.Copy(outfile, infile); nil != err {  
                     status = http.StatusInternalServerError  
                     return  
                }  
                res.Write([]byte("uploaded file:" + hdr.Filename + ";length:" + strconv.Itoa(int(written))))  
           }  
      }  
 } 

这篇关于无法使用GOLANG和POLYMER http将上传的文件保存在服务器上:无此文件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！