Servlet.service() for servlet [jsp] in context with path [/struts2Study] threw exception
java.lang.IllegalStateException: Must have the StrutsPrepareFilter execute before this one
出現這個異常說明web.xml配置出現錯誤,說明沒有 StrutsPrepareFilter過濾器,在web.xml中配置成org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter,而不是org.apache.struts2.dispatcher.ng.filter.StrutsExecuteFilter,