@Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    if (!ServletFileUpload.isMultipartContent(request)) {
        PrintWriter writer = response.getWriter();
        writer.println("Error: enctype=multipart/form-data");
        writer.flush();
        return;
    }
    DiskFileItemFactory diskFileItemFactory = new DiskFileItemFactory();
    diskFileItemFactory.setSizeThreshold(1024 * 1024 * 3);
    diskFileItemFactory.setRepository(new File(System.getProperty("java.io.tmpdir")));
    ServletFileUpload fileUpload = new ServletFileUpload(diskFileItemFactory);
    fileUpload.setFileSizeMax(1024 * 1024 * 30);
    fileUpload.setSizeMax(1024 * 1024 * 50);
    String fileUploadPath = getServletContext().getRealPath("./") ;
    File uploadFileDir = new File(fileUploadPath);
    try {
        @SuppressWarnings("unchecked")
        List<FileItem> fileItemList = fileUpload.parseRequest(new ServletRequestContext(request));
        if (fileItemList != null && fileItemList.size() > 0) {
        for (FileItem item : fileItemList) {
            String fn = new File(item.getName()).getName();
            String fp = fileUploadPath + File.separator + fn;
            File storeFile = new File(fp);
            System.out.println(fp);
            item.write(storeFile);
            request.setAttribute("resMsg", "OK");
        }
        }
    } catch (Exception ex) {
        request.setAttribute("exMsg", ex.getMessage());
    }

    }