上传单个文件
准备
1. 如果你项目中使用了spring security的话，参考上一篇文章，使用上篇的第二种方法，并去掉MultipartFilter（如果有配置的话），否则得不到文件
2. 流程中的变量（如用var标签定义的变量），都需要实现Serializable接口。
实现过程
在pom.xml文件中加入下列依赖：
<!-- 支持文件上传 -->
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.2.1</version>
</dependency>
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.4</version>
</dependency>在spring-servlet.xml(Spring MVC的配置文件)中加入文件上传解析器：
<!-- 文件上传解析器-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!-- one of the properties available; the maximum file size in bytes -->
<property name="maxUploadSize" value="10485760"/>
</bean>实体类，记住要实现Serializable接口，属性类型是MultipartFile：
@Component
public class GoodsEntity implements Serializable{
private static final long serialVersionUID = 1L;
private MultipartFile images;
public MultipartFile getImages() {
return images;
}
public void setImages(MultipartFile images) {
this.images = images;
}
}流程定义代码，没什么特别的：
<?xml version="1.0" encoding="UTF-8"?>
<flow xmlns="http://www.springframework.org/schema/webflow"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/webflow
http://www.springframework.org/schema/webflow/spring-webflow-2.0.xsd">
<var name="goods" class="com.huanle.model.entity.GoodsEntity"/>
<view-state id="viewfirst" view="/views/user/releasegoods/release_first.jsp" model="goods">
<transition on="submit" to="viewsecond"></transition>
</view-state>
<view-state id="viewsecond" view="/views/user/releasegoods/second.jsp" model="goods">
<transition on="submit" to="performReleaseGoodsAction"></transition>
</view-state>
<action-state id="performReleaseGoodsAction" >
<evaluate expression="goodsService.save(goods)"></evaluate>
<transition to="returntouserindex"></transition>
</action-state>
<end-state id="returntouserindex" view="/views/user/seller/index.jsp"></end-state>
<global-transitions>
<transition on="cancel" to="returntouserindex"></transition>
</global-transitions>
</flow>上传表单代码，无需特别配置：
<form:form action="${flowExecutionUrl}&_eventId=submit&${_csrf.parameterName}=${_csrf.token}" method="post" commandName="goods" enctype="multipart/form-data">
<input type="hidden" name="_flowExecutionKey" value="${flowExecutionKey}"/>
商品图片：<form:input id="images" path="images" type="file" multiple="multiple" />
<input type="submit" >
</form:form>就这样就可以了
上传多个文件
上传单个文件可在前面上传单个文件基础上稍作修改就可以实现了。
实现
首先，实体类要修改，使用List来存储多个文件：
@Component
public class GoodsEntity implements Serializable{
private static final long serialVersionUID = 1L;
private List<MultipartFile> images;
public List<MultipartFile> getImages() {
return images;
}
public void setImages(List<MultipartFile> images) {
this.images = images;
}
}上传表单也要修改：
<form:form action="${flowExecutionUrl}&_eventId=submit&${_csrf.parameterName}=${_csrf.token}" method="post" commandName="goods" enctype="multipart/form-data">
<input type="hidden" name="_flowExecutionKey" value="${flowExecutionKey}"/>
商品图片：<form:input path="images" type="file" multiple="multiple"/>
<input type="submit" value="提交">
</form:form>增加一个multiple="multiple"属性即可。
