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);
}