比如说你有个SampleAction，在execute(ActionMapping mapping, ...)中写了句
return mapping.findForward("some_page");
那么你相应的在struts-config.xml中就必须有类似如下的配置：
<action ... type="org.someone.struts.action.SampleAction">
<forward name="some_page" path="/samplepages/some_page.jsp"></forward>
</action>