@RequestMapping("/download")
	public void download(HttpServletResponse res ,HttpServletRequest req) throws IOException {
	    OutputStream os = res.getOutputStream();
	    try {
	        res.reset();
	        res.setHeader("Content-Disposition", "attachment; filename=down.xls");
	        res.setContentType("application/octet-stream; charset=utf-8");
	        os.write(FileUtils.readFileToByteArray(getDictionaryFile(req)));
	        os.flush();
	    } finally {
	        if (os != null) {
	            os.close();
	        }
	    }
	}

	 private File getDictionaryFile(HttpServletRequest req) {
		File file =new File(req.getSession().getServletContext().getRealPath("/WEB-INF/down.xls"));
		return file;
	}

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