【springboot+easypoi】大数据量excel导出

@RequestMapping("export")
public void export(HttpServletResponse response) {
        Map<String, Object> params = new HashMap<>();
        Workbook workbook = bigExcel(1, params, null, new ExportParams("海贼王", "海贼王"),         new Page<>());
        ExcelExportUtil.closeExportBigExcel();
        downLoadExcel("海贼王.xls", response, workbook);
}
private Workbook bigExcel(int pageNum, Map<String, Object> params, Workbook workbook, ExportParams exportParams, Page<SysUser> page) {
        page.setCurrent(pageNum);
        page.setSize(1000);
        page.setCondition(params);
        page = this.getData(sysUserService.queryPage(page));
        List<SysUser> users =             FastJsonUtils.toList(FastJsonUtils.toJSONString(page.getRecords()), SysUser.class);
        workbook = ExcelExportUtil.exportBigExcel(exportParams, SysUser.class, users);
        if (page.getPages() > pageNum) {
                bigExcel(pageNum + 1, params, workbook, exportParams, page);
        }
        return workbook;
}

private void downLoadExcel(String fileName, HttpServletResponse response, Workbook workbook) {
        try {
            response.setCharacterEncoding("UTF-8");
            response.setHeader("Content-Disposition", "attachment;filename=" +         URLEncoder.encode(fileName, "UTF-8"));
            response.setHeader("content-Type", "application/vnd.ms-excel");
            workbook.write(response.getOutputStream());
        } catch (IOException e) {
            throw new NormalException(e.getMessage());
        }
}