文件上传功能

1. 引入依赖

<!--文件上传-->
<dependency>
   <groupId>commons-fileupload</groupId>
   <artifactId>commons-fileupload</artifactId>
   <version>1.3.1</version>
</dependency>

2. 后端

 //上传文件
private void testUpload(HttpServletRequest request, HttpServletResponse response) throws Exception {
   
        //1.确认该操作是否支持文件上传操作，前端页面上是否写入:enctype="multipart/form-data"
        if (ServletFileUpload.isMultipartContent(request)) {
   
            //2.创建磁盘工厂对象,用于将页面上传的文件保存到磁盘中
            DiskFileItemFactory factory = new DiskFileItemFactory();
            //3.获取Servlet文件上传核心对象
            ServletFileUpload fileUpload = new ServletFileUpload(factory);
            //4.从request中读取数据
            List<FileItem> fileItems