spring mvc文件上传

 <!-- SpringMVC上传文件时，需要配置MultipartResolver处理器 -->  
    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">  
        <property name="defaultEncoding" value="UTF-8"/>  
        <!-- 指定所上传文件的总大小不能超过200KB。注意maxUploadSize属性的限制不是针对单个文件，而是所有文件的容量之和 -->  
        <property name="maxUploadSize" value="20000000"/>  
    </bean>  
      
    <!-- SpringMVC在超出上传文件限制时，会抛出org.springframework.web.multipart.MaxUploadSizeExceededException -->  
    <!-- 该异常是SpringMVC在检查上传的文件信息时抛出来的，而且此时还没有进入到Controller方法中 -->  
    <bean id="exceptionResolver" class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">  
        <property name="exceptionMappings">  
            <props>  
                <!-- 遇到MaxUploadSizeExceededException异常时，自动跳转到/WEB-INF/jsp/error_fileupload.jsp页面 -->  
                <prop key="org.springframework.web.multipart.MaxUploadSizeExceededException">error_fileupload</prop>  
            </props>  
        </property>  
    </bean>  

package com.example.controller;

import java.util.Iterator;

import javax.servlet.http.HttpServletRequest;

import org.springframework.format.datetime.joda.MillisecondInstantPrinter;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.MultipartHttpServletRequest;
import org.springframework.web.multipart.commons.CommonsMultipartFile;
import org.springframework.web.multipart.commons.CommonsMultipartResolver;

@Controller
public class uploadController {
    @RequestMapping("upload")
    public String init(){
        return "upload";
    }
    /**
     * 单文件上传
     * @param file
     * @return
     */
    @RequestMapping("upload_submit")
    public String submit(@RequestParam CommonsMultipartFile file){
        System.out.println(file.getOriginalFilename());
        System.out.println(file.getSize());
        System.out.println(file.getContentType());
        return "hello";
    }
    /**
     * 多文件上传
     * @param request
     * @return
     */
    @RequestMapping("upload_submit2")
    public String sumbit2(HttpServletRequest request){
        CommonsMultipartResolver commonsMultipartResolver=new CommonsMultipartResolver(request.getSession().getServletContext());
        if(commonsMultipartResolver.isMultipart(request)){
            MultipartHttpServletRequest multipartHttpServletRequest=(MultipartHttpServletRequest) request;
            Iterator<String> iterator=multipartHttpServletRequest.getFileNames();
            while(iterator.hasNext()){
                MultipartFile multipartFile=multipartHttpServletRequest.getFile(iterator.next());
                System.out.println(multipartFile.getOriginalFilename());
            }
        }
        return "hello";
    }

}