springMVC實作 多檔案上傳的方式有兩種，一種是我們經常使用的以位元組流的方式進行檔案上傳，另外一種是使用springMVC包裝好的解析器進行上傳。這兩種方式對于實 現多檔案上傳效率上卻有着很大的差距，下面我們通過執行個體來看一下這兩種方式的實作方式，同時比較一下在效率上到底存在着多大的差距。
2.配置springAnnotation-servlet.xml檔案（檔案名稱可以自定義，隻要和web.xml中引入的名稱一樣即可）：
<?xml version="1.0" encoding="UTF-8"?>
<!-- Bean頭部 -->
<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">
<!-- 注解掃描包 -->
<context:component-scan base-package="com.tgb.web.controller.annotation"></context:component-scan>
<!-- 代替下面的兩行代碼 -->
<mvc:annotation-driven/>
<!-- 靜态資源通路 -->
<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>
</beans>
3. 配置web.xml檔案：
<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的分發器 -->
<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>
<!-- 表示當Tomcat已啟動的時候初始化這個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> <!--設定你想用的字元集，我這裡用的是GB18030-->
</init-param>
<init-param>
<param-name>forceEncoding</param-name>
<param-value>true</param-value>
</init-param>
</filter>
<filter-mapping>
<url-pattern>/*</url-pattern> <!--設定你想過濾的頁面或者是Servlet，根據自己的需要配置-->
</filter-mapping>
<servlet-mapping>
<servlet-name>springMVC</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
4. jsp頁面代碼：
<%@ 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位元組流輸入上傳檔案</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="上傳" >
</form>
<br>
<hr align="left" width="60%" color="#FF0000" size="3">
<h1>springMVC包裝類上傳檔案</h1>
<form name="userForm2" action="/springMVC7/file/upload2" enctype="multipart/form-data" method="post"">
<div id="newUpload2">
<input type="button" id="btn_add2" value="增加一行" >
</body>
</html>
5.實作上傳功能的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 {
//拿到輸出流，同時重命名上傳的檔案
FileOutputStream os = new FileOutputStream("H:/" + new Date().getTime() + files[i].getOriginalFilename());
//拿到上傳檔案的輸入流
FileInputStream in = (FileInputStream) files[i].getInputStream();
//以寫位元組的方式寫檔案
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("上傳出錯");
}
}
return "/success";
@RequestMapping("/upload2" )
public String upload2(HttpServletRequest request,HttpServletResponse response) throws IllegalStateException, IOException {
//建立一個通用的多部分解析器
CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver(request.getSession().getServletContext());
//判斷 request 是否有檔案上傳,即多部分請求
if(multipartResolver.isMultipart(request)){
//轉換成多部分request
MultipartHttpServletRequest multiRequest = (MultipartHttpServletRequest)request;
//取得request中的所有檔案名
Iterator<String> iter = multiRequest.getFileNames();
while(iter.hasNext()){
//記錄上傳過程起始時的時間，用來計算上傳時間
//取得上傳檔案
MultipartFile file = multiRequest.getFile(iter.next());
if(file != null){
//取得目前上傳檔案的檔案名稱
String myFileName = file.getOriginalFilename();
//如果名稱不為“”,說明該檔案存在，否則說明該檔案不存在
if(myFileName.trim() !=""){
System.out.println(myFileName);
//重命名上傳後的檔案名
String fileName = "demoUpload" + file.getOriginalFilename();
//定義上傳路徑
String path = "H:/" + fileName;
File localFile = new File(path);
file.transferTo(localFile);
//記錄上傳該檔案後的時間
int finaltime = (int) System.currentTimeMillis();
System.out.println(finaltime - pre);
}
@RequestMapping("/toUpload" )
public String toUpload() {
return "/upload";
}
6.最後看背景列印資料，資料來源于背景列印的上傳檔案所用的時間，第一幅圖檔是使用位元組流寫入方式完成三個檔案上傳中每個檔案用時，第二幅圖檔是使用springMVC包裝好的解析器進行的三個相同的檔案上傳中每個檔案的用時：
位元組流實作檔案上傳的傳遞效率，結果顯示傳遞三個檔案用時分别為534ms，453ms和387ms。
使用springMVC解析器進行檔案上傳用時分别為2ms，1ms和2ms。
通過對比這兩種方式我們可以發現使用springMVC進行多檔案的效率顯然要比字元流寫入方式效率上要高得多。