SpringMVC中的文件上传

这是用的是SpringMVC-3.1.1、commons-fileupload-1.2.2和io-2.0.1

首先是web.xml

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<?xml version="1.0" encoding="UTF-8"?>

<web-app version="2.5"

xmlns="http://java.sun.com/xml/ns/javaee"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<servlet>

<servlet-name>upload</servlet-name>

<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>

<load-on-startup>1</load-on-startup>

</servlet>

<servlet-mapping>

<servlet-name>upload</servlet-name>

<url-pattern>/</url-pattern>

</servlet-mapping>

<filter>

<filter-name>SpringCharacterEncodingFilter</filter-name>

<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>

<init-param>

<param-name>encoding</param-name>

<param-value>UTF-8</param-value>

</init-param>

</filter>

<filter-mapping>

<filter-name>SpringCharacterEncodingFilter</filter-name>

<url-pattern>/*</url-pattern>

</filter-mapping>

<welcome-file-list>

<welcome-file>/WEB-INF/jsp/user/add.jsp</welcome-file>

</welcome-file-list>

</web-app>

接下来是SpringMVC的配置文件upload-servlet.xml

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<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xmlns:mvc="http://www.springframework.org/schema/mvc"

xmlns:context="http://www.springframework.org/schema/context"

xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<context:component-scan base-package="com.jadyer"/>

<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">

<property name="prefix" value="/WEB-INF/jsp/"/>

<property name="suffix" value=".jsp"/>

</bean>

<!-- 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="200000"/>

</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>

</beans>

下面是用于上传的表单页面//WEB-INF//jsp//user//add.jsp

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<%@ page language="java" pageEncoding="UTF-8"%>

<form action="<%=request.getContextPath()%>/user/add" method="POST" enctype="multipart/form-data">

username: <input type="text" name="username"/><br/>

nickname: <input type="text" name="nickname"/><br/>

password: <input type="password" name="password"/><br/>

yourmail: <input type="text" name="email"/><br/>

yourfile: <input type="file" name="myfiles"/><br/>

yourfile: <input type="file" name="myfiles"/><br/>

yourfile: <input type="file" name="myfiles"/><br/>

<input type="submit" value="添加新用户"/>

</form>

下面是上传成功后打印用户信息的页面//WEB-INF//jsp//user//list.jsp

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<%@ page language="java" pageEncoding="UTF-8"%>

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>

<c:forEach items="${users}" var="user">

${user.value.username}----${user.value.nickname}----${user.value.password}----${user.value.email}

<a href="<%=request.getContextPath()%>/user/${user.value.username}">查看</a>

<a href="<%=request.getContextPath()%>/user/${user.value.username}/update">编辑</a>

<a href="<%=request.getContextPath()%>/user/${user.value.username}/delete">删除</a>

<br/>

</c:forEach>

<br/>

<a href="<%=request.getContextPath()%>/user/add">继续添加用户</a>

下面是上传文件内容过大时的提示页面//WEB-INF//jsp//error_fileupload.jsp

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<%@ page language="java" pageEncoding="UTF-8"%>

<h1>文件过大，请重新选择</h1>

接下来是用到的实体类User.Java

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package com.jadyer.model;

/**

* User

* @author 宏宇

* @create May 12, 2012 1:24:43 AM

*/

public class User {

private String username;

private String nickname;

private String password;

private String email;

/*==四个属性的getter()、setter()略==*/

public User() {}

public User(String username, String nickname, String password, String email) {

this.username = username;

this.nickname = nickname;

this.password = password;

this.email = email;

}

}

最后是核心的UserController.java

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package com.jadyer.controller;

import java.io.File;

import java.io.IOException;

import java.util.HashMap;

import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.io.FileUtils;

import org.springframework.stereotype.Controller;

import org.springframework.ui.Model;

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 com.jadyer.model.User;

/**

* SpringMVC中的文件上传

* @see 第一步：由于SpringMVC使用的是commons-fileupload实现，故将其组件引入项目中

* @see 这里用到的是commons-fileupload-1.2.2.jar和commons-io-2.0.1.jar

* @see 第二步：在####-servlet.xml中配置MultipartResolver处理器。可在此加入对上传文件的属性限制

* @see 第三步：在Controller的方法中添加MultipartFile参数。该参数用于接收表单中file组件的内容

* @see 第四步：编写前台表单。注意enctype="multipart/form-data"以及<input type="file" name="****"/>

* @author 宏宇

* @create May 12, 2012 1:26:21 AM

*/

@Controller

@RequestMapping("/user")

public class UserController {

private final static Map<String,User> users = new HashMap<String,User>();

//模拟数据源,构造初始数据

public UserController(){

users.put("张起灵", new User("张起灵", "闷油瓶", "02200059", "menyouping@yeah.net"));

users.put("李寻欢", new User("李寻欢", "李探花", "08866659", "lixunhuan@gulong.cn"));

users.put("拓拔野", new User("拓拔野", "搜神记", "05577759", "tuobaye@manhuang.cc"));

users.put("孙悟空", new User("孙悟空", "美猴王", "03311159", "sunhouzi@xiyouji.zh"));

}

@RequestMapping("/list")

public String list(Model model){

model.addAttribute("users", users);

return "user/list";

}

@RequestMapping(value="/add", method=RequestMethod.GET)

public String addUser(){

return "user/add";

}

@RequestMapping(value="/add", method=RequestMethod.POST)

public String addUser(User user, @RequestParam MultipartFile[] myfiles, HttpServletRequest request) throws IOException{

//如果只是上传一个文件，则只需要MultipartFile类型接收文件即可，而且无需显式指定@RequestParam注解

//如果想上传多个文件，那么这里就要用MultipartFile[]类型来接收文件，并且还要指定@RequestParam注解

//并且上传多个文件时，前台表单中的所有<input type="file"/>的name都应该是myfiles，否则参数里的myfiles无法获取到所有上传的文件

for(MultipartFile myfile : myfiles){

if(myfile.isEmpty()){

System.out.println("文件未上传");

}else{

System.out.println("文件长度: " + myfile.getSize());

System.out.println("文件类型: " + myfile.getContentType());

System.out.println("文件名称: " + myfile.getName());

System.out.println("文件原名: " + myfile.getOriginalFilename());

System.out.println("========================================");

//如果用的是Tomcat服务器，则文件会上传到\\%TOMCAT_HOME%\\webapps\\YourWebProject\\WEB-INF\\upload\\文件夹中

String realPath = request.getSession().getServletContext().getRealPath("/WEB-INF/upload");

//这里不必处理IO流关闭的问题，因为FileUtils.copyInputStreamToFile()方法内部会自动把用到的IO流关掉，我是看它的源码才知道的

FileUtils.copyInputStreamToFile(myfile.getInputStream(), new File(realPath, myfile.getOriginalFilename()));

}

}

users.put(user.getUsername(), user);

return "redirect:/user/list";

}

}

补充：记得建立这个目录，用于存放上传的文件，即//WEB-INF//upload//