关于OutputStream问题

 try {
            String paths = path + ".zip" ;
            File files = new File(paths); // 要下载的文件绝对路径
            InputStream ins;
            ins = new BufferedInputStream(new FileInputStream(files));
            byte[] buffer = new byte[ins.available()];
            ins.read(buffer);
            ins.close();

            response.reset();
            response.addHeader("Content-Disposition", "attachment;filename="+ new 
            String(files.getName().getBytes()));
            OutputStream ous = new BufferedOutputStream(response.getOutputStream());
            response.setContentType("application/octet-stream");
            response.addHeader("Content-Length",String.valueOf(ins.available()));
            ous.write(buffer);
            ous.flush();
            ous.close();
            files.delete();
            Utils.delcutFile(fileName,mac,pathUrl);
        } catch (Exception e) {
            e.printStackTrace();
        }

请问一下这个异常是为什么呀.stream closed 

 response.addHeader("Content-Length",String.valueOf(ins.available()));

你要把异常信息贴出来啊