How to get Recent Journal Article in Action Class Liferay6.1 Hook

The Recent Article is stored in PortletSession. And it's a Object of 

java.util.Stack having 20 Objects of JournalArticle.

The Snippet is as below.

PortletSession portletSession = portletRequest.getPortletSession();

        Stack<JournalArticle> recentArticles =
            (Stack<JournalArticle>)portletSession.getAttribute(
                WebKeys.JOURNAL_RECENT_ARTICLES);