MultipartFile attach
HttpServletRequest re
commons-io-2.0.jar (一定要用2.0以上的版本，否则没有copyInputStreamToFile方法)
commons-fileupload-1.2.1.jar
@RequestMapping(value="/add",method=RequestMethod.POST)
public String userAdd(@Validated User user,BindingResult br,MultipartFile attach,HttpServletRequest re) throws IOException{//一定要紧跟validate写，验证结果类，中间如果有其他参数，就会报错
if(br.hasErrors()){
return "user/add";
}
if(!attach.isEmpty()){
String realPath = re.getSession().getServletContext().getRealPath("/Resources/upload");
System.out.println(realPath);
File f = new File(realPath+"/"+attach.getOriginalFilename());
FileUtils.copyInputStreamToFile(attach.getInputStream(), f);
}
users.put(user.getNickname(), user);
//客户端跳转
return "redirect:/user/users";
}
<!-- 设置multipartResolver才能完成文件上传 -->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<property name="maxUploadSize" value="5000000"></property>
</bean>
<sf:form method="post" modelAttribute="user" enctype="multipart/form-data">
<%-- <sf:textarea path=""/> --%>
Username:<sf:input path="username"/> <sf:errors path="username"></sf:errors></br>
Password:<sf:password path="password"/> <sf:errors path="password"></sf:errors></br>
Nickname:<sf:input path="nickname"/>
<!-- 对于没有path的，必须要在参数里面传，才能接收 -->
FileUpload:<input type="file" name="attach"/>
<input type="submit" value="添加用户" />
</sf:form>
