download zipped excel help!!!

[alex ho kwong yiu]

Hi all,

i believe it is related to i/o question,

there is an existing code which work fine to output excel stream for user download /save in local directory

   ServletOutputStream out= response.getOutputStream();
		try {
			//Setup the output
			log.debug("type: " + request.getParameter("type"));
			String datatype = request.getParameter("type");
			if (datatype.equals("Excel")) {
				log.debug("EXCEL");
				 
				HSSFWorkbook wb = (HSSFWorkbook) request.getSession().getAttribute("workbook");
				request.getSession().removeAttribute("workbook");
	        	                                String contentType = "";
				DateFormat dateFormat = new SimpleDateFormat("MM-dd-yyyy");
                                          		Date date = new Date();
		        response.setHeader("Content-Disposition","attachment; filename=" + dateFormat.format(date).toString() + ".xls");
				response.setContentType(contentType);
				out = response.getOutputStream();
				wb.write(out);		
				out.flush();
				out.close();
				System.out.println("Download servlet Pass"); 

i try to modify it to output compressed excel(zipped version) for user download but fail, it show java.util.zip.ZipException: no current ZIP entry

what's wrong of the modified code?

  protected void doGet(HttpServletRequest request, HttpServletResponse response) 
		throws ServletException, IOException {
		ServletOutputStream out= response.getOutputStream();
		ZipOutputStream zipOut = new ZipOutputStream(out);
		try {
			//Setup the output
			log.debug("type: " + request.getParameter("type"));
			String datatype = request.getParameter("type");
			if (datatype.equals("Excel")) {
				log.debug("EXCEL");		 
				HSSFWorkbook wb = (HSSFWorkbook) request.getSession().getAttribute("workbook");
				//HSSFWorkbook wb = (HSSFWorkbook) request.getAttribute("workbook");
				if(wb == null) {
					System.out.println("Download servlet Fail 123");
				}
				request.getSession().removeAttribute("workbook");
	        	String contentType = "application/zip";
		DateFormat dateFormat = new SimpleDateFormat("MM-dd-yyyy");
		        Date date = new Date();
		        ByteArrayOutputStream output = new ByteArrayOutputStream();
		        ZipEntry entry = new ZipEntry(dateFormat.format(date));
		        zipOut.putNextEntry(entry);
		        response.setHeader("Content-Disposition","attachment; filename=" + dateFormat.format(date).toString() + ".zip");
				response.setContentType(contentType);
				out = response.getOutputStream();
				zipOut = new ZipOutputStream(out);
				wb.write(zipOut);		
				zipOut.closeEntry();
				out.flush();
				out.close();
				
				zipOut.flush();
				zipOut.close();
				System.out.println("Download servlet Pass");

i have searched post, it seems that i need read file (inputstream) and then transfer outputstream of zipOut, but it seems doesn't fix my case,
the wb object stored in memory

please help