GroupExchangeNetworkFeedBack groupExchangeNetworkFeedBack = groupExchangeNetworkFeedBackBiz.getGroupExchangNetworkFeedBackById(feedBackId);		String attachName = groupExchangeNetworkFeedBack.getAttachment();		String attachUrl = groupExchangeNetworkFeedBack.getAttachmentUrl();	           		// 取得HttpServletResponse对象        HttpServletResponse response = ServletActionContext.getResponse();		//获取web应用程序在服务器上的路径需要访问ServletAPI		ServletContext context = ServletActionContext.getServletContext();		 // 通知浏览器以下载方式打开文件      //  response.setHeader("content-disposition", "attachment;filename=" + URLEncoder.encode(exportFileName, "utf-8"));		response.setHeader("content-disposition", "attachment;filename=" + new String(attachName.getBytes("gbk"), "ISO8859-1"));      //  String realPath = context.getRealPath(attachUrl);           // 构造子节输入流        InputStream is = new FileInputStream(attachUrl + "/" + attachName);     // 构造子节输出流        OutputStream os = response.getOutputStream();        byte[] b = new byte[1024];        int len = 0;        while ((len = is.read(b)) > 0) {            os.write(b, 0, len);        }        is.close();        os.close();                return null;