准备
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/webflowhttp://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
参考文档
Handling File Uploads in webflow
Spring’s multipart (file upload) support in Spring MVC
