@RequestMapping("/fileDownload.do")
public void fileDownload(RMap rmap, ModelMap model, HttpServletRequest request, HttpServletResponse response) throws IOException {		
	UMap umap = fileService.selectAttachFile(rmap, model);
	byte[] imageData = (byte[]) umap.get("file");
	String filename = (String) umap.get("attach_file_name");
	response.setContentType("application/octet-stream");
	response.setHeader("Content-Disposition", "attachment;filename=" + filename);
	response.getOutputStream().write(imageData);
}