SpringMvc下载excel文件

@RequestMapping
	public void download(HttpServletRequest request,
			HttpServletResponse response) throws Exception {
		response.setContentType("text/html;charset=UTF-8"); 
		BufferedInputStream in = null;
		BufferedOutputStream out = null;
		request.setCharacterEncoding("UTF-8");
		String rootpath = request.getSession().getServletContext().getRealPath(
				"/");
		String fileName = request.getParameter("f");
		fileName=CommonProperty.getValue(fileName);
		try {
			File f = new File(rootpath + "template/" + fileName);
			response.setContentType("application/x-excel");
			response.setCharacterEncoding("UTF-8");
			  response.setHeader("Content-Disposition", "attachment; filename="+fileName);
			response.setHeader("Content-Length",String.valueOf(f.length()));
			in = new BufferedInputStream(new FileInputStream(f));
			out = new BufferedOutputStream(response.getOutputStream());
			byte[] data = new byte[1024];
			int len = 0;
			while (-1 != (len=in.read(data, 0, data.length))) {
				out.write(data, 0, len);
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if (in != null) {
				in.close();
			}
			if (out != null) {
				out.close();
			}
		}

	}