简单的文件下载

public void downloadDeviceTemp(HttpServletRequest request, HttpServletResponse response) {
        try {
            String realPath = request.getSession().getServletContext().getRealPath("/page");
            //读到流中
            InputStream stream = new FileInputStream(realPath + "/examine/excel/devicetemp/device_keypoint_temp.xlsx");
            //重置 清除首部的空白行
            response.reset();
            //不存在的文件类型,出现下载提示
            response.setContentType("bin");
            String fileName = new String("重点点位设备导入模板.xlsx".getBytes("gb2312"), "ISO8859-1");
            response.addHeader("Content-Disposition", "attachment; filename="" + fileName + """);
            byte[] b = new byte[100];
            int len;
            while ((len = stream.read(b)) > 0) {
                response.getOutputStream().write(b, 0, len);
            }
            stream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }