HSSFWORKbook导出Excel问题

我想意见导出多个Excel，filename = new String(filename.getBytes("gbk"), "ISO-8859-1") + ".xls";// 处理中文文件名
response.setContentType("application/vnd.ms-excel");
response.setHeader("Content-disposition", "attachment;filename=" + filename);
// response.setContentLength(workbook.getBytes().length);
log.info("buildExcelDocument in size:" + workbook.getBytes().length);
ouputStream = response.getOutputStream();
workbook.write(ouputStream);
ouputStream.flush();
ouputStream.close();
workbook.close();
多次调用这个为什么只导出一个Excel文件啊

http://blog.csdn.net/jimmy609/article/details/41038537