JavaWeb导出Excel问题小计

注意，要在写入response.getOutputStream()输出流前设置response相关配置，否则无法写入response配置

进入如response.setHeader源码，可知当response的outputstream有数据后便不可以设置response其他配置

 正确代码，可如下

    @RequestMapping("/export")
    public void export(HttpServletResponse response) throws Exception {
        ByteArrayOutputStream outputStream=new ByteArrayOutputStream();
        String fileName = excelService.exportExcel(outputStream);
        response.setContentType(MediaType.APPLICATION_OCTET_STREAM_VALUE);
        response.setCharacterEncoding("UTF-8");
        response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName, "UTF-8"));
　　　　 //一定在response设置后再写入数据
        response.getOutputStream().write(outputStream.toByteArray());
        System.out.println("导出成功");
    }