java导出excel 浏览器直接下载或者或以文件形式导出

 /**
  * excel表格直接下载
  */
 public static void exportExcelByDownload(HSSFWorkbook wb,HttpServletResponse httpServletResponse,String fileName) throws Exception {
     //响应类型为application/octet- stream情况下使用了这个头信息的话，那就意味着不想直接显示内容
     httpServletResponse.setContentType(MediaType.APPLICATION_OCTET_STREAM_VALUE);

     //attachment为以附件方式下载
     httpServletResponse.setHeader("Content-Disposition","attachment;filename=" + URLEncoder.encode(
             fileName + ".xls",
             "utf-8"));
     /**
      * 代码里面使用Content-Disposition来确保浏览器弹出下载对话框的时候。
      * response.addHeader("Content-Disposition","attachment");一定要确保没有做过关于禁止浏览器缓存的操作
      */
     httpServletResponse.setHeader("Cache-Control", "No-cache");
     httpServletResponse.flushBuffer();

     wb.write(httpServletResponse.getOutputStream());
     wb.close();
 }

 /**
  * excel以文件的形式导出
  * @throws Exception
  */
 public static void exportExcelByFile(HSSFWorkbook wb,String fileName,String path) throws Exception{

     ByteArrayOutputStream stream = new ByteArrayOutputStream();
     wb.write(stream);
     FileOutputStream outputStream = new FileOutputStream(path + fileName);
     outputStream.write(stream.toByteArray());
     stream.close();
     outputStream.close();

 }