java 下载文件的问题，太纠结了

文件能够正确的上传回显，但是下载的时候后台总是会报文件找不到的错误，（http:\localhost:80\gms\upload\123456.xlsx (文件名、目录名或卷标语法不正确。)）但是这个路径直接贴到浏览器里面是可以下载到的，下载的代码如下：

public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { try { request.setCharacterEncoding("UTF-8"); String downFilename = request.getParameter("curfile"); String filepath = request.getParameter("path"); response.setContentType("text/plain"); response.setHeader("Location", downFilename); response.setHeader("Content-Disposition", "attachment; filename=" + downFilename); OutputStream outputStream = response.getOutputStream(); InputStream inputStream = new FileInputStream(filepath); byte[] buffer = new byte[1024]; int i = -1; while ((i = inputStream.read(buffer)) != -1) { outputStream.write(buffer, 0, i); } outputStream.flush(); outputStream.close(); } catch (FileNotFoundException e1) { e1.printStackTrace(); System.out.println("没有找到您要的文件"); } catch (Exception e) { e.printStackTrace(); System.out.println("系统错误，请及时与管理员联系"); } } public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); }