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();

}