这是我的struts.xml配置文件，其中有一个登录拦截器。我想使用不同的文件上传拦截器，以不同的操作使用不同的文件类型，并使用给定的最大大小。但是问题出在这里：它总是采用默认值maximumSize和allowedType。请帮我我在哪里做错了？

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">

    <struts>
<constant name="struts.enable.DynamicMethodInvocation"
    value="false" />
<constant name="struts.devMode" value="false" />
<constant name="struts.custom.i18n.resources"
    value="ApplicationResources" />

<package name="default" extends="struts-default" namespace="/">
    <result-types>
        <result-type name="tiles"
            class="org.apache.struts2.views.tiles.TilesResult" />
    </result-types>

    <interceptors>
        <interceptor name="nlogin" class="com.picvik.interceptor.LoginInterceptor"/>
        <interceptor-stack name="loginStack">
            <interceptor-ref name="servletConfig"/>
            <interceptor-ref name="params"/>
            <interceptor-ref name="nlogin"/>
            <interceptor-ref name="prepare"/>
            <interceptor-ref name="chain"/>
            <interceptor-ref name="modelDriven"/>
            <interceptor-ref name="staticParams"/>
            <interceptor-ref name="params"/>
            <interceptor-ref name="conversionError"/>
            <interceptor-ref name="validation"/>
            <interceptor-ref name="workflow"/>
        </interceptor-stack>
    </interceptors>
    <!-- <default-interceptor-ref name="loginStack"/>  -->

    <global-results>
        <result name="login" type="tiles">/login.tiles</result>
    </global-results>


    <action name="home" 
        class="com.picvik.action.HomeAction">
        <interceptor-ref name="loginStack"/>
        <result name="success" type="tiles">/home.tiles</result>
        <result name="error" type="tiles">/welcome.tiles</result>
    </action>
    <action name="registration" 
        class="com.picvik.action.RegisterAction" method="execute">
        <result name="success" type="tiles">/register.tiles</result>
    </action>
    <action name="register" 
        class="com.picvik.action.RegisterAction" method="register">
        <result name="success" type="tiles">/registerverify.tiles</result>
        <result name="error" type="tiles">/register.tiles</result>
        <result name="input" type="tiles">/register.tiles</result>
    </action>
    <action name="verify" 
        class="com.picvik.action.RegisterAction" method="verify">
        <result name="success" type="tiles">/login.tiles</result>
        <result name="error" type="tiles">/registerverify.tiles</result>
    </action>

     <action name="login" class="com.picvik.action.LoginAction">
        <result name="success" type="tiles">/home.tiles</result>
        <result name="input" type="tiles">/login.tiles</result>
    </action>

    <action name="dologin" class="com.picvik.action.LoginAction" method="login">
        <interceptor-ref name="defaultStack"/>
        <result name="success" type="tiles">/home.tiles</result>
        <result name="input" type="tiles">/login.tiles</result>
    </action>

    <action name="logout" class="com.picvik.action.LoginAction" method="logout">
        <interceptor-ref name="defaultStack"/>
        <result name="success" type="tiles">/login.tiles</result>
    </action>

    <action name="viewprofile" class="com.picvik.action.ViewProfileAction">
        <interceptor-ref name="loginStack"/>
        <result name="success" type="tiles">/viewprofile.tiles</result>
    </action>
    <action name="editprofile" class="com.picvik.action.ViewProfileAction">
        <interceptor-ref name="loginStack"/>
        <result name="success" type="tiles">/editprofile.tiles</result>
    </action>
    <action name="saveprofile" class="com.picvik.action.ViewProfileAction" method = "saveProfile">
        <interceptor-ref name="loginStack"/>
        <result name="success" type="tiles">/home.tiles</result>
        <result name="input" type="tiles">/editprofile.tiles</result>
    </action>

    <action name="changeprofilephoto" class="com.picvik.action.ChangeProfilePhotoAction">
        <interceptor-ref name="loginStack"/>
        <result name="success" type="tiles">/changephoto.tiles</result>
        <result name="input" type="tiles">/changephoto.tiles</result>
    </action>

    <action name="uploadprofilephoto"
            class="com.picvik.action.ChangeProfilePhotoAction" method="uploadProfilePhoto">
         <interceptor-ref name="fileUpload">
            <param name="maximumSize">2097152</param>
            <param name="allowedTypes">
                image/png,image/gif,image/jpeg,image/pjpeg
            </param>
        </interceptor-ref>
        <interceptor-ref name="loginStack"></interceptor-ref>
        <result name="success" type= "redirectAction">
            <param name="actionName">viewprofile</param>
        </result>
        <result name="input" type="tiles">/changephoto.tiles</result>
    </action>
    <!-- video upload-->
    <action name="videouploader"
            class="com.picvik.action.UploadVideoAction" method="execute">
        <interceptor-ref name="loginStack"></interceptor-ref>
        <result name="success" type="tiles">/videoupload.tiles</result>
    </action>

    <action name="uploadvideo"
            class="com.picvik.action.UploadVideoAction" method="uploadVideo">
         <interceptor-ref name="fileUpload">
            <param name="maximumSize">209715200</param>
            <param name="allowedTypes">
                video/mp4
            </param>
        </interceptor-ref>
        <interceptor-ref name="loginStack"></interceptor-ref>
        <result name="success" type= "redirectAction">
            <param name="actionName">editvideo</param>
        </result>
        <result name="input" type="tiles">/videoupload.tiles</result>
    </action>
    <action name="editvideo"
            class="com.picvik.action.UploadVideoAction" method="editVideo">
        <interceptor-ref name="loginStack"></interceptor-ref>
        <result name="success" type= "redirectAction">
            <param name="actionName">home</param>
        </result>
        <result name="input" type="tiles">/editvideo.tiles</result>
    </action>
    <action name="savevideos"
            class="com.picvik.action.UploadVideoAction" method="saveVideo">
        <interceptor-ref name="loginStack"></interceptor-ref>
        <result name="success" type= "redirectAction">
            <param name="actionName">listVideo</param>
        </result>
        <result name="error" type="tiles">/editvideo.tiles</result>
    </action>
    <!-- video upload ends here-->

    <!-- photo upload -->
    <action name="photouploader"
            class="com.picvik.action.UploadPhotoAction">
        <interceptor-ref name="loginStack"></interceptor-ref>
        <result name="success" type="tiles">/photoupload.tiles</result>
    </action>

    <action name="uploadphoto"
            class="com.picvik.action.UploadPhotoAction" method="uploadPhoto">
         <interceptor-ref name="fileUpload">
            <param name="maximumSize">20971520</param>
            <param name="allowedTypes">
                image/png,image/gif,image/jpeg,image/pjpeg
            </param>
        </interceptor-ref>
        <interceptor-ref name="loginStack"></interceptor-ref>
        <result name="success" type= "redirectAction">
            <param name="actionName">editphoto</param>
        </result>
        <result name="input" type="tiles">/photoupload.tiles</result>
    </action>

    <action name="editphoto"
            class="com.picvik.action.UploadPhotoAction" method="editPhoto">
        <interceptor-ref name="loginStack"></interceptor-ref>
        <result name="success" type= "redirectAction">
            <param name="actionName">home</param>
        </result>
        <result name="input" type="tiles">/editphoto.tiles</result>
    </action>
    <action name="savephotos"
            class="com.picvik.action.UploadPhotoAction" method="savePhoto">
        <interceptor-ref name="loginStack"></interceptor-ref>
        <result name="success" type= "redirectAction">
            <param name="actionName">listalbum</param>
        </result>
        <result name="error" type="tiles">/editphoto.tiles</result>
    </action>

    <action name="listalbum"
            class="com.picvik.action.ViewAlbumAction" method="listAlbum">
        <interceptor-ref name="loginStack"></interceptor-ref>
        <result name="success" type="tiles">/listalbum.tiles</result>
    </action>

    <action name="listphoto"
            class="com.picvik.action.ViewAlbumAction" method="listPhoto">
        <interceptor-ref name="loginStack"></interceptor-ref>
        <result name="success" type="tiles">/listphoto.tiles</result>
    </action>

    <action name="listalbumphoto"
            class="com.picvik.action.ViewAlbumAction" method="listAlbumPhoto">
        <interceptor-ref name="loginStack"></interceptor-ref>
        <result name="success" type="tiles">/listalbumphoto.tiles</result>
    </action>

    <action name="viewphoto"
            class="com.picvik.action.ViewAlbumAction" method="viewPhoto">
        <interceptor-ref name="loginStack"></interceptor-ref>
        <result name="success" type="tiles">/viewphoto.tiles</result>
    </action>

    <action name="commentonphoto"
            class="com.picvik.action.CommentAction" method="commentOnPhoto">
        <interceptor-ref name="loginStack"></interceptor-ref>
        <result name="success" type= "redirectAction">
            <param name="actionName">listphoto</param>
        </result>
    </action>

    <action name="commentonalbum"
            class="com.picvik.action.CommentAction" method="commentOnAlbum">
        <interceptor-ref name="loginStack"></interceptor-ref>
        <result name="success" type= "redirectAction">
            <param name="actionName">listalbum</param>
        </result>
    </action>

</package>