Spring MVC上传文件

网页上传文件，首先需要了解MIME多媒体类型

http://www.w3school.com.cn/media/media_mimeref.asp

再看web.xml配置，巩固之前的知识

<?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>webtest</display-name>



  <listener>

        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>

    </listener>

    <context-param>

        <param-name>contextConfigLocation</param-name>

        <param-value>

            /WEB-INF/config/applicationContext.xml

            /WEB-INF/config/codeifAction.xml

        </param-value>

    </context-param>



    <servlet>

        <servlet-name>dispatcherServlet</servlet-name>

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

        <init-param>

            <param-name>contextConfigLocation</param-name>

            <param-value>/WEB-INF/config/codeifAction.xml</param-value>

        </init-param>

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

    </servlet>

    <!-- 拦截所有以do结尾的请求 -->

    <servlet-mapping>

        <servlet-name>dispatcherServlet</servlet-name>

        <url-pattern>*.do</url-pattern>

    </servlet-mapping>



  <welcome-file-list>

    <welcome-file>index.do</welcome-file>

  </welcome-file-list>

</web-app>

接着是applicationContext.xml

<?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:p="http://www.springframework.org/schema/p"

    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/context http://www.springframework.org/schema/context/spring-context-3.0.xsd"

    default-lazy-init="true">



    <!-- 启动Spring MVC的注解功能，完成请求和注解POJO的映射 -->

    <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter" lazy-init="false" />



    <!-- 另外最好还要加入DefaultAnnotationHandlerMapping，不然会被 XML或其它的映射覆盖！ -->

    <bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping" />



    <!-- 对模型视图名称的解析，即在模型视图名称添加前后缀 -->

    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" p:prefix="/WEB-INF/jsp/" p:suffix=".jsp" />



    <!-- 支持上传文件 -->

    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"/>



</beans>

在spring中，文件被包装为multipart类型。

接着是controller

package com.codeif.action;



import java.io.File;

import java.util.Date;



import javax.servlet.http.HttpServletRequest;



import org.springframework.stereotype.Controller;

import org.springframework.ui.ModelMap;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestParam;

import org.springframework.web.multipart.MultipartFile;



@Controller

public class UploadAction {



    @RequestMapping(value = "/upload.do")

    public String upload(@RequestParam(value = "file", required = false) MultipartFile file, HttpServletRequest request, ModelMap model) {



        System.out.println("开始");

        String path = request.getSession().getServletContext().getRealPath("upload");//获取网页根目录的upload目录的绝对路径

        String fileName = file.getOriginalFilename();  //从页面上传过来的文件名

//        String fileName = new Date().getTime()+".jpg";

        System.out.println(path);

        File targetFile = new File(path, fileName);

        if(!targetFile.exists()){

            targetFile.mkdirs();

        }



        //保存

        try {

            file.transferTo(targetFile);

        } catch (Exception e) {

            e.printStackTrace();

        }

        model.addAttribute("fileUrl", request.getContextPath()+"/upload/"+fileName);



        return "result";

    }



}

最后是网页表单类型：

<!DOCTYPE html>  

<html>  

<head>  

<meta charset="utf-8">  

<title>上传图片</title>  

</head>  

<body>  

<form action="upload.do" method="post" enctype="multipart/form-data">  

<input type="file" name="file" /> <input type="submit" value="Submit" /></form>  

</body>  

</html> 

注意这里的enctype="multipart/form-data"

这就是设置请求的mime的，默认为application/x-www-form-urlencoded，不能用于文件上传；只有使用了multipart/form-data，才能完整的传递文件数据，进行下面的操作.

这样就完成了文件上传

 

可用uploadify插件美化上传

 

注意，spring数据绑定中若出现了multipartFile，则不能绑定其他POJO对象，因为会在multipartFile中数据会干扰对象绑定，只能使用简单类型的数据。