Return Excel document from Spring Controller using Apache POI

Question

I am trying to send a Excel file back to the user. In some way my excel file gets corrupted even if it is empty. When I open the file Excel tells me that the file is corrupt. If i remove ``` response.getOutputStream().write(excelService.exportEventsToCSV()); ``` I get an empty excel file. ``` @RequestMapping(value = "/events/excel", method = RequestMethod.GET) public void getEventsAsExcel(HttpServletResponse response) { try { response.setHeader("Content-disposition", "attachment; filename=test.xls"); response.getOutputStream().write(excelService.exportEventsToCSV()); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } ``` My XML generation is very simple. Just empty document ``` @Override public byte[] exportEventsToCSV() { try { HSSFWorkbook workbook = new HSSFWorkbook(); HSSFSheet worksheet = workbook.createSheet("POI Worksheet"); HSSFCellStyle cellStyle = workbook.createCellStyle(); workbook.write(fileOut); return workbook.getBytes(); } catch (FileNo…

Accepted Answer

You seem to be doing some very strange things around getting the output out, and I'm fairly sure that `workbook.getBytes()` isn't returning what you think it is...

I would strongly suggest you change `exportEventsToCSV` to return the workbook, then you can do the much simpler:

```
Workbook wb = excelService.exportEventsToCSV();
response.setHeader("Content-disposition", "attachment; filename=test.xls");
wb.write( response.getOutputStream() );
```

That should work fine and give the end user the kind of thing they were expecting

Return Excel document from Spring Controller using Apache POI

Solution

Problem