@RequestMapping("update")
    public String update(Person per,MultipartFile file,HttpServletRequest request) throws Exception {
     String realPath = request.getSession().getServletContext().getRealPath("upload");
     String fileName = file.getOriginalFilename();//取文件名
     //解决同名问题
     fileName = UUID.randomUUID().toString().replace("-", "")+fileName.substring(fileName.lastIndexOf("."));
     File f1=new File(realPath,fileName);
     if(!f1.exists()){
         f1.mkdirs();//如果不存在则创建其目录
     }
     file.transferTo(f1);//执行上传
     per.setFilepath(fileName);//改变一下路径
        perdb.updatePerson(per);// 实现修改功能
        return "redirect:list.do";
    }

springmvc.xml的配置

    <!-- 配置视图解析器 -->
    <bean
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!-- 前缀 -->
        <property name="prefix" value="/WEB-INF/per/"></property>
        <!-- 后缀 -->
        <property name="suffix" value=".jsp"></property>
    </bean>
    <!-- 配置spring mvc上传图片大小,multipartResolver名不能改 -->
    <bean id="multipartResolver"
        class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
    <property name="maxUploadSize" value="104857600"></property>
    </bean>

下载

   @RequestMapping("download")
    public String download(HttpServletRequest request,HttpServletResponse response,Person per) throws Exception{//下载
        String filepath="//upload//"+per.getFilepath();//从upload下取图片的路径
        FileDownLoad.download(filepath, request, response);
        return null;
    }