springMVC实现多文件上传的方式有两种，一种是我们经常使用的以字节流的方式进行文件上传，另外一种是使用springMVC包装好的解析器进行上传。这两种方式对于实现多文件上传效率上却有着很大的差距，下面我们通过实例来看一下这两种方式的实现方式，同时比较一下在效率上到底存在着多大的差距。
1.下载相关jar包。需要引入的jar出了springMVC的jar包外，还需要引入com.springsource.org.apache.commons.fileupload-1.2.0.jar和com.springsource.org.apache.commons.io-1.4.0.jar。所有的jar包可以通过“点击这里”进行下载。
2.配置springAnnotation-servlet.xml文件（文件名称可以自定义，只要和web.xml中引入的名称一样即可）：
<?xml version="1.0" encoding="UTF-8"?>
<!-- Bean头部 -->
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:util="http://www.springframework.org/schema/util"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.0.xsd">
<!-- 注解扫描包 -->
<context:component-scan base-package="com.tgb.web.controller.annotation"></context:component-scan>
<!-- 代替下面的两行代码 -->
<mvc:annotation-driven/>
<!-- 静态资源访问 -->
<mvc:resources location="/img/" mapping="/img/**"/>
<mvc:resources location="/js/" mapping="/js/**"/>
<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<property name="defaultEncoding" value="utf-8"></property>
<property name="maxUploadSize" value="10485760000"></property>
<property name="maxInMemorySize" value="40960"></property>
</bean>
</beans>3. 配置web.xml文件：
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
<display-name>springMVC1</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>springMVC</servlet-name>
<!-- springMVC的分发器 -->
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath*:config/springAnnotation-servlet.xml</param-value>
</init-param>
<!-- 表示当Tomcat已启动的时候初始化这个Servlet -->
<load-on-startup>1</load-on-startup>
</servlet>
<filter>
<filter-name>encodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value> <!--设置你想用的字符集，我这里用的是GB18030-->
</init-param>
<init-param>
<param-name>forceEncoding</param-name>
<param-value>true</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>encodingFilter</filter-name>
<url-pattern>/*</url-pattern> <!--设置你想过滤的页面或者是Servlet，根据自己的需要配置-->
</filter-mapping>
<servlet-mapping>
<servlet-name>springMVC</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>4. jsp页面代码：<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<script type="text/javascript" src="../js/jquery-1.7.2.js"></script>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<script type="text/javascript">
i = 1;
j = 1;
$(document).ready(function(){
$("#btn_add1").click(function(){
document.getElementById("newUpload1").innerHTML+=‘<div id="div_‘+i+‘"><input name="file" type="file" /><input type="button" value="删除" onclick="del_1(‘+i+‘)"/></div>‘;
i = i + 1;
});
$("#btn_add2").click(function(){
document.getElementById("newUpload2").innerHTML+=‘<div id="div_‘+j+‘"><input name="file_‘+j+‘" type="file" /><input type="button" value="删除" onclick="del_2(‘+j+‘)"/></div>‘;
j = j + 1;
});
});
function del_1(o){
document.getElementById("newUpload1").removeChild(document.getElementById("div_"+o));
}
function del_2(o){
document.getElementById("newUpload2").removeChild(document.getElementById("div_"+o));
}
</script>
</head>
<body>
<h1>springMVC字节流输入上传文件</h1>
<form name="userForm1" action="/springMVC7/file/upload" enctype="multipart/form-data" method="post">
<div id="newUpload1">
<input type="file" name="file">
</div>
<input type="button" id="btn_add1" value="增加一行" >
<input type="submit" value="上传" >
</form>
<br>
<br>
<hr align="left" width="60%" color="#FF0000" size="3">
<br>
<br>
<h1>springMVC包装类上传文件</h1>
<form name="userForm2" action="/springMVC7/file/upload2" enctype="multipart/form-data" method="post"">
<div id="newUpload2">
<input type="file" name="file">
</div>
<input type="button" id="btn_add2" value="增加一行" >
<input type="submit" value="上传" >
</form>
</body>
</html>5.实现上传功能的java bean：package com.tgb.web.controller.annotation.upload;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.util.Date;
import java.util.Iterator;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.swing.filechooser.FileNameExtensionFilter;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
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;
import org.springframework.web.servlet.ModelAndView;
import com.tgb.web.controller.entity.User;
@Controller
@RequestMapping("/file")
public class UploadController {
@RequestMapping("/upload" )
public String addUser(@RequestParam("file") CommonsMultipartFile[] files,HttpServletRequest request){
for(int i = 0;i<files.length;i++){
System.out.println("fileName---------->" + files[i].getOriginalFilename());
if(!files[i].isEmpty()){
int pre = (int) System.currentTimeMillis();
try {
//拿到输出流，同时重命名上传的文件
FileOutputStream os = new FileOutputStream("H:/" + new Date().getTime() + files[i].getOriginalFilename());
//拿到上传文件的输入流
FileInputStream in = (FileInputStream) files[i].getInputStream();
//以写字节的方式写文件
int b = 0;
while((b=in.read()) != -1){
os.write(b);
}
os.flush();
os.close();
in.close();
int finaltime = (int) System.currentTimeMillis();
System.out.println(finaltime - pre);
} catch (Exception e) {
e.printStackTrace();
System.out.println("上传出错");
}
}
}
return "/success";
}
@RequestMapping("/upload2" )
public String upload2(HttpServletRequest request,HttpServletResponse response) throws IllegalStateException, IOException {
//创建一个通用的多部分解析器
CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver(request.getSession().getServletContext());
//判断 request 是否有文件上传,即多部分请求
if(multipartResolver.isMultipart(request)){
//转换成多部分request
MultipartHttpServletRequest multiRequest = (MultipartHttpServletRequest)request;
//取得request中的所有文件名
Iterator<String> iter = multiRequest.getFileNames();
while(iter.hasNext()){
//记录上传过程起始时的时间，用来计算上传时间
int pre = (int) System.currentTimeMillis();
//取得上传文件
MultipartFile file = multiRequest.getFile(iter.next());
if(file != null){
//取得当前上传文件的文件名称
String myFileName = file.getOriginalFilename();
//如果名称不为“”,说明该文件存在，否则说明该文件不存在
if(myFileName.trim() !=""){
System.out.println(myFileName);
//重命名上传后的文件名
String fileName = "demoUpload" + file.getOriginalFilename();
//定义上传路径
String path = "H:/" + fileName;
File localFile = new File(path);
file.transferTo(localFile);
}
}
//记录上传该文件后的时间
int finaltime = (int) System.currentTimeMillis();
System.out.println(finaltime - pre);
}
}
return "/success";
}
@RequestMapping("/toUpload" )
public String toUpload() {
return "/upload";
}
}
字节流实现文件上传的传递效率，结果显示传递三个文件用时分别为534ms，453ms和387ms。
使用springMVC解析器进行文件上传用时分别为2ms，1ms和2ms。
通过对比这两种方式我们可以发现使用springMVC进行多文件的效率显然要比字符流写入方式效率上要高得多。
springMVC两种方式实现多文件上传及效率比较,布布扣,bubuko.com
原文：http://blog.csdn.net/a1314517love/article/details/24183273
