CustomActionSupport （继承ActionSupport的类）

public class CustomActionSupport extends ActionSupport {
    /**
     * 获取session
     * @return Map
     * @since Dec 23, 2009
     */
    @SuppressWarnings("unchecked")
    public Map getSession() {
       ActionContext ctx = ActionContext.getContext();
       Map session = ctx.getSession();
       return session;
    }
}