Struts2上传，文件上传成功，在jsp页面取不到文件名

struts.xml
XML code:

<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<!-- 系统常量定义，定义上传文件临时存放路径 -->
<constant name="struts.multipart.saveDir" value="c:\upload\"></constant>

<include file="struts-default.xml" />

<package name="base" extends="struts-default">
<interceptors>
<interceptor name="Example" class="interceptors.ExampleInterceptor">
<param name="param">iamxu</param>
</interceptor>
</interceptors>

<package name="C04.4" extends="struts-default">
<!-- Action名字，类以及导航页面定义 -->
<!-- 通过Action类处理才导航的的Action定义 -->
<action name="upload" class="base.UploadAction">
<result name="input">/upload.jsp</result>
<result name="success">/result.jsp</result>
</action>
</package>

</struts>





UploadAction.java
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