JAVA判斷上傳表單中file是否為空

原文鏈接：https://www.cnblogs.com/koal/p/4491432.html   （侵刪）

<form action="update.do"method="post" enctype="multipart/form-data" >  
文件上傳：<input name="myfile"  type="file"><br>  
<input type="submit" value="上傳">  
</form>

MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request; 
        CommonsMultipartFile file = (CommonsMultipartFile) multipartRequest.getFile("myfile");
         if (!file.isEmpty()) {
            System.out.println("非空");
        }else
        {
            System.out.println("空的");
        }