java.lang.IllegalStateException: Cannot ?400报错

excel导出弹出下载框时报错，但是东西都可以出来，对程序没有什么影响，但是控制台报错，java.lang.IllegalStateException: Cannot call sendRedirect() after the response has been committed  看着不舒服，求大神解决下！！！以下是添加下载框的代码。。。

String fileName = "台账统计表" + DateUtils.getDate("yyyyMMddHHmmss");
        ByteArrayOutputStream os = new ByteArrayOutputStream();
        workbook.write(os);
        byte[] content = os.toByteArray();
        InputStream is = new ByteArrayInputStream(content);
        // 设置response参数，可以打开下载页面
        response.reset();
        response.setContentType("application/vnd.ms-excel;charset=utf-8");
        response.setHeader("Content-Disposition", "attachment;filename="+ new String((fileName + ".xls").getBytes(), "iso-8859-1"));
        ServletOutputStream out = response.getOutputStream();
        BufferedInputStream bis = null;
        BufferedOutputStream bos = null;

        try {
            bis = new BufferedInputStream(is);
            bos = new BufferedOutputStream(out);
            byte[] buff = new byte[2048];
            int bytesRead;
            // Simple read/write loop.
            while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {
                bos.write(buff, 0, bytesRead);
            }
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        } finally {
            if (bis != null)
                bis.close();
            if (bos != null)
                bos.close();
        }