Exception on invoking write() method twice on XSSFWorkbook instance.

[Renjith Panikar]

I could see the same topic being covered at several places, but i dint get a clear picture from those.

Issue is,

I have a download link in JSp page to download excel file. I have this file in HTTPSession.
To pop up save excel box, i invoked write(OutputStream) on XSSFWorkbook instance.
But when i click on the link for the second time, this exception occoured.

Request processing failed; nested exception is org.apache.xmlbeans.impl.values.XmlValueDisconnectedException

it will be really helpful if some one can help me to resolve it.

[Ulf Dittmer]

Please post an SSCCE (<- this is a link) that demonstrates the problem.

[Renjith Panikar]

	/**
	* This method is used to download the error excel file whcih is 
	* created after validating an excel file.
	* Error file will be set to HTTPSession only once. 
	* Each time when a user clicks the download link in a JSP file, a URL similar to 
	* "http://host:port/context1/test.htm?&event=downloadError" will be triggered to the application.
	* On receiving the request, this method will be invoked.
	* This method takes the Excel file from session and write it to output stream.
	*/
	@RequestMapping(params = "event=downloadError")
	public ModelAndView writeToExcel(HttpServletRequest request,
			HttpServletResponse response) throws IOException {
		HttpSession session = request.getSession();
		Workbook workbook = (Workbook) session.getAttribute("Failed_File"); 
        response.setContentType("application/vnd.ms-excel");
        response.setHeader("Content-Disposition","attachment; filename=Error.xlsx");
        workbook.write(response.getOutputStream());
		response.flushBuffer();
		return null;
	}

First time when the user clicks the link, a pop up will come asking the user to save/open the file.
User will click on the download link again, if he close the file by mistake.
This time, it will not give a pop up and an exception "Request processing failed;
nested exception is org.apache.xmlbeans.impl.values.XmlValueDisconnectedException " can be
seen on console. This exception occours when we invoke .write(OutputStream) on
same Workbook instance for the second time. Hpe this give a clear picture.

[Renjith Panikar]

RESOLVED

This is what i did to resolve it.
Instead of keeping the Workbook in session, I took getBytes() from MultipartFile (File uploaded) and kept it in session.
Validation errors are also uploaded to session.
Now I have both Original file and errors in session.
I will create a new XSSFWorkbook instance from the following code.
Workbook workbook = null;
try{
workbook = new XSSFWorkbook(new ByteArrayInputStream(multipartFileBytes));
}catch(OfficeXmlFileException exception){
workbook = new HSSFWorkbook(new ByteArrayInputStream(multipartFileBytes));
}
Now, workbook.write(OutputStream) will be invoked on different instances of Workbook on each request.

Let me know if you see any issues in this approach.