java生成多个Excel数据文件打成压缩包zip下载，在putNextEntry(entry)报 stream close 的错误？

Question

java生成多个Excel数据文件打成压缩包zip下载，总是在第二个Excel文件时在putNextEntry(entry)报 stream close 的错误？使用的是ZipOutputStream

```public ByteArrayOutputStream downFileByStream(HttpServletResponse response,List excels,List fileNames) throws IOException{
OutputStream toClient =null;
ZipOutputStream zipOut=null;
try {
toClient=new BufferedOutputStream(response.getOutputStream());

zipOut = new ZipOutputStream(toClient);
Date now=new Date();
SimpleDateFormat f=new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
response.setContentType("application/zip");
response.setHeader("Connection", "close"); // 表示不能用浏览器直接打开

response.setHeader("Content-Disposition","attachment; filename="+ new String(("费用统计- "+f.format(now)+".zip").getBytes("GB2312"), "ISO8859-1"));
response.setHeader("Pragma", "public");
response.setHeader("Cache-Control","must-revalidate, post-check=0,pre-check=0");
response.setHeader("Expires", "0");
//zipOut.setEncoding("UTF8");
for(int i=0;i<excels.size();i++){
// zipOut = new ZipOutputStream(bout);
ZipEntry entry = new ZipEntry( new String(fileNames.get(i).getBytes("GB2312"), "ISO8859-1"));
zipOut.putNextEntry(entry);
excels.get(i).write(zipOut);
// zipOut.closeEntry();
//zipOut.flush();

    }

// zipOut.flush();
// zipOut.closeEntry();//20190821新加了关闭实体，测试一下是否可以了
// zipOut.close();//再增加一个流关闭
}catch (Exception e){
e.printStackTrace();
System.out.println("导出失败");
}

求解大神

Answer 1

刚才在网上找到了答案
XSSFWorkbook的write()方法传去MemoryStream对象后，会自动关闭传入的参数，导致再次使用putNextEntry()方法是报错Stream closed

解决方法：
将XSSFWorkbook转换成ByteArrayOutputStream，用ByteArrayOutputStream对象将流写入zip对象中

        ZipEntry entry = new ZipEntry(fileNames);
        zipOut.putNextEntry(entry);
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        workbook.get(i).write(bos);
        bos.writeTo(zipOut);
        zipOut.closeEntry();
        bos.close();