Send Excel file to the SpringBoot-Angular2 client

I have to send an Excel from the SpringBoot server to the client in Angular2, Excel does not exist and can not be created because I do not have written permissions, so it will have to be put in a buffer or something ...

The problem I'm having is that I can not put the HSSFWorkbook where I have the data to the answer that I have to send to the client.

 @RequestMapping(method = RequestMethod.GET, path = "/{download}/{data}/{nameFile}", produces = MediaType.APPLICATION_JSON_VALUE)
            public synchronized void download(HttpServletResponse response , @PathVariable("data") Boolean data, @PathVariable("nameFile") String nameFile) {

            response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
             response.setHeader("Content-disposition", "attachment; filename="+nameFile+"result.xlsx");

             String eyelash = "People";

             try {  
                HSSFWorkbook workbook = new HSSFWorkbook();
                HSSFSheet sheet = workbook.createSheet(eyelash);

                String[] header = { "Name","Surname","Dni","Age","Tlf" };
                HSSFRow rowhead = sheet.createRow((short) 0);
                HSSFCell cell;
                int cellnum = 0;

                if (data) {
                    int myRowData = 1;
                    HSSFRow row = sheet.createRow((short) myRowData);
                    ArrayList list = mlService.selectAll();

                    for (int i = 0; i < list.size(); i++) {
                        row.createCell(0).setCellValue(list.get(i).getName().substring(0, 4));
                        row.createCell(1).setCellValue(list.get(i).getSurname().substring(4, 6));
                        row.createCell(2).setCellValue(list.get(i).getDni());
                        row.createCell(3).setCellValue(list.get(i).getYear());
                        row.createCell(4).setCellValue(list.get(i).getTlf());

                        myRowData++;
                        row = sheet.createRow((short) myRowData);
                    }
                } 

                final InputStream is = new FileInputStream(workbook) ; //error
                IOUtils.copy(is, response.getOutputStream());
                response.flushBuffer();

            } catch (Exception ex) {
                ex.printStackTrace();
                System.out.println(ex.getMessage());
                // deal with error, e.g. response.setStatus(500) to signal an internal server error
            }
    }

Then I wait for a boolean and the file type (there can be many), in this example I have said that it is always the same.

Then the Http response where I add the headers and tell the browser what kind of format the file has.

Then I build the file with HSSFWorkbook, the construction is correct And finally I want to send it to the client where I try to put the woorkbook to the inputStream file but it does not stop because it is not a file or something of that and supposedly when I get it, it would get into the response buffer ...

I do not know if I'm on the right track or what ... besides I get an error ...

Finally the SpringBoot will create the Excel and send it to the client without having created it.

Thank you.