struts2 json plugin includeProperties 包孕MAP属性

<action name="dl" class="com.dqgb.action.document.DocumentAction" method="getDocumentList">
???<result type="json">
????<param name="includeProperties">^documentss\[\d+\]\.attachGroup\.attachs.*</param>
???</result>
</action>

?

其中attachs为Set集合