在Java Excel系列文章（二）中心先生成电子表格，然后提供下载功能返回页面如下：
先在(二)中将输出流转化为字节数组，返回至controller层
byte[] byteArray = out.toByteArray();
return byteArray;```
@ApiOperation(value="导出箱号模板", notes="导出箱号模板")
@RequestMapping(value="/exportExcelTemplate",method = RequestMethod.GET)
public void exportExcelTemplate(HttpServletRequest request, HttpServletResponse response) throws IOException{
String fileName = new String("箱号信息模板.xls".getBytes("UTF-8"),"iso-8859-1");
byte[] templateBytes = containerNumService.exportExcelTemplate();
response.setContentType("application/x-msdownload");
response.setContentLength(templateBytes.length);
response.setHeader("Content-Disposition", "attachment;filename="+fileName);//设置下载的文件名
response.getOutputStream().write(templateBytes);
}
