'Duplicate headers received from server' Error in Chrome 16 with EPPlus 2.9

Question

I'm playing around with EPPlus 2.9 and for some reason I'm getting Duplicate headers received from server errors when I try to download single .xlsx files using Chrome 16 (It works fine in IE9).

I'm using this tutorial and I've narrowed down the problem to this line of code:

        Response.AppendHeader("Content-Disposition",
        "attachment; " +
        "filename=\"ExcelReport.xlsx\"; " +
        "size=" + fileBytes.Length.ToString() + "; " +
        "creation-date=" + DateTime.Now.ToString("R") + "; " +
        "modification-date=" + DateTime.Now.ToString("R") + "; " +
        "read-date=" + DateTime.Now.ToString("R"));

My useragent:

Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.7 (KHTML, like Gecko) Chrome/16.0.912.75 Safari/535.7

I read on this Chrome forum page that Chrome doesn't like commas (,) in Content-Disposition headers and they should be replaced with semicolons (;).

Anybody got any ideas or getting the same errors?

Greg · Accepted Answer · 2013-09-30T13:56:13.843

11

I'm dumb, DateTime.Now.ToString("R") produces Thu, 26 Jan 2012 02:05:44 GMT

I fixed it by doing this:

String timestamp_without_commas = DateTime.Now.ToString("R").Replace(",","");

Response.AppendHeader("Content-Disposition",
    "attachment; " +
    "filename=\"ExcelReport.xlsx\"; " +
    "size=" + fileBytes.Length.ToString() + "; " +
    "creation-date=" + timestamp_without_commas + "; " +
    "modification-date=" + timestamp_without_commas + "; " +
    "read-date=" + timestamp_without_commas);

I'm used to IE being cranky and Chrome playing nice...

edited Sep 30 '13 at 13:56

answered Jan 26 '12 at 07:08

Greg

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3

Had a similar problem. We had commas in the filename... Thanks – NotMe Aug 03 '12 at 13:52

score 3 · Answer 2 · answered Jan 15 '13 at 19:31

3

I had the same issue and I also had the semi colon after attachment correctly. I found my issue was having commas in the filename. So I replaced them with dashes.

answered Jan 15 '13 at 19:31

kyleb

1,968
7
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score 0 · Answer 3 · answered Aug 24 '12 at 07:59

 /// <summary>
        /// ExportToExcel is a method used for Export To Excel with template file.
        ///
        /// </summary>
        /// <param name="templateFile">The fully qualified name of the new file, or the relative file name. Do not end the path with the directory separator character.</param>
        /// <param name="dt">Datatable for export.</param>
        /// <param name="printHeaders">Datatable's header used or not, when Export it. </param>
        /// <param name="exportFileName">provide fileName only not path. </param>
        /// <param name="Response">System.Web.HttpResponse. </param>
        /// <param name="sheetNames">arg[0] means provide sheet name where you want to load data. \n (Optional Parameter) arg[1] means provide sheet name where you want to edit. (Optional Parameter) arg[2] means if your intention is to Edit sheet so provide searchText.</param>
        /// 
        public static string ExportToExcel(FileInfo templateFile, DataTable dt, bool printHeaders, string exportFileName, System.Web.HttpResponse Response, params String[] sheetNames)
        {
            try
            {
                using (ExcelPackage p = new ExcelPackage(templateFile, false))
                {
                    EPPlus.AddSheetWithTemplate(p, dt, sheetNames[0], printHeaders);


                    String[] clientName = exportFileName.Split(new char[] { '_' }, 2);

                    if (sheetNames.Count() > 2)
                    {
                        ExcelPackagePlusLibrary.EPPlus.EditSheet(p, sheetNames[1], sheetNames[2], clientName[0] ?? exportFileName);
                    }

                    Byte[] fileBytes = p.GetAsByteArray(); //Read the Excel file in a byte array

                    //Clear the response
                    Response.ClearHeaders();
                    Response.ClearContent();
                    Response.Clear();

                    //Response.Cookies.Clear();


                    //Add the header & other information
                    //Response.Cache.SetCacheability(System.Web.HttpCacheability.Private);
                    //Response.CacheControl = "private";
                    //Response.Charset = System.Text.UTF8Encoding.UTF8.WebName;
                    //Response.ContentEncoding = System.Text.UTF8Encoding.UTF8;
                    //Response.AppendHeader("Content-Length", fileBytes.Length.ToString());
                    //Response.AppendHeader("Pragma", "cache");
                    //Response.AppendHeader("Expires", "60");
                    Response.AddHeader("Content-Disposition",
                    "attachment; " +
                    "filename=" + exportFileName + "; " +
                    "size=" + fileBytes.Length.ToString() + "; " +
                    "creation-date=" + DateTime.Now.ToString("R").Replace(",", "") + "; " +
                    "modification-date=" + DateTime.Now.ToString("R").Replace(",", "") + "; " +
                    "read-date=" + DateTime.Now.ToString("R").Replace(",", ""));

                    //Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
                    Response.ContentType = "application/x-msexcel";

                    //Write it back to the client
                    Response.BinaryWrite(fileBytes);
                    Response.Flush();
                    Response.Close();

                    /* Download to Client Side. */
                    //DirectoryInfo dir = new DirectoryInfo(Server.MapPath("~/Testing/Downloaded/" + DateTime.Now.ToString("MM-dd-yyyy")));
                    //if (!dir.Exists)
                    //{
                    //    dir.Create();
                    //}
                    //File.WriteAllBytes(dir.FullName + "\\" + fileName, fileBytes);

                    return String.Empty;
                }
            }
            catch (Exception ex)
            {
                _ErrorMessage = ex.Message.ToString();
                return _ErrorMessage;
            }
        }

Just for info, the filename should have quotes around them: "filename=" + "\"" + exportFileName + "\"" + "; " because there is a bug in Firefox where it will truncate the name after the first space if the filename is not surrounded with quotes. Reference http://kb.mozillazine.org/Filenames_with_spaces_are_truncated_upon_download — Hans Petter Naumann, Apr 09 '14 at 11:29

'Duplicate headers received from server' Error in Chrome 16 with EPPlus 2.9

3 Answers3

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