springmvc实现文件上传功能

<dependency>
  <groupId>commons-fileupload</groupId>
  <artifactId>commons-fileupload</artifactId>
  <version>1.3.2</version>
</dependency>

<form action="http://localhost:8080/springmvc_Web_exploded/fff" method="post" enctype="multipart/form-data">
 <input type="file" name="file" id="filer_input" multiple="multiple">
 <input type="submit" value="Submit">
</form>

<!-- 文件上传的bean-->
 <bean id="multipartResolver"
   class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
  <!--上传文件的最大大小，单位为字节 -->
  <property name="maxUploadSize" value="17367648787"></property>

  <!-- 上传文件的编码 -->
  <property name="defaultEncoding" value="UTF-8"></property>
</bean>

@PostMapping("/fff")
 public String file(@PathVariable("file")MultipartFile file, HttpServletRequest req) throws IOException {

 //判断文件不存在
  if (file.isEmpty()){
   return "faile.html";
  }

  //我想放到这个地方文件的路径
  String realPath = req.getServletContext().getRealPath("/WEB-INF/file");
  //返回客户端文件系统中的原始文件名
  String filename = file.getOriginalFilename();
  File myFile = new File(realPath, filename);
  if (!myFile.getParentFile().exists()){
   myFile.getParentFile().mkdir();
   System.out.println("文件夹被创建了");
  }

 //将前端传过来的文件，传到自己new的File对象中
  file.transferTo(myFile);

  return "success.html";
 }