spring mvc实现文件上传与下载功能

  <!-- spring mvc -->  <dependency>   <groupId>org.springframework</groupId>   <artifactId>spring-webmvc</artifactId>   <version>4.3.13.RELEASE</version>  </dependency>    <!-- 文件上传与下载 -->  <dependency>   <groupId>commons-fileupload</groupId>   <artifactId>commons-fileupload</artifactId>   <version>1.3.3</version>  </dependency>

 <bean id="multipartResolver"   class="org.springframework.web.multipart.commons.CommonsMultipartResolver">   <!-- 上传文件大小上限，单位为字节（10MB） -->  <property name="maxUploadSize">    <value>10485760</value>   </property>   <!-- 请求的编码格式，必须和jSP的pageEncoding属性一致，以便正确读取表单的内容，默认为ISO-8859-1 -->  <property name="defaultEncoding">   <value>UTF-8</value>  </property> </bean>

<form action="upload" enctype="multipart/form-data" method="post"> <table>  <tr>   <td>文件描述:</td>   <td><input type="text" name="description"></td>  </tr>  <tr>   <td>请选择文件:</td>   <td><input type="file" name="file"></td>  </tr>  <tr>   <td><input type="submit" value="上传"></td>  </tr> </table></form>

//上传文件会自动绑定到MultipartFile中@RequestMapping(value="/upload",method=RequestMethod.POST)public String upload(HttpServletRequest request,  @RequestParam("description") String description,  @RequestParam("file") MultipartFile file) throws Exception {  //如果文件不为空，写入上传路径 if(!file.isEmpty()) {  //上传文件路径  String path = request.getServletContext().getRealPath("/file/");  //上传文件名  String filename = file.getOriginalFilename();  File filepath = new File(path,filename);  //判断路径是否存在，如果不存在就创建一个  if (!filepath.getParentFile().exists()) {   filepath.getParentFile().mkdirs();  }  //将上传文件保存到一个目标文件当中  file.transferTo(new File(path + File.separator + filename));  return "success"; } else {  return "error"; } }