struts.xml文件的某个package中添加<default-action-ref name="error"></default-action-ref>
<package name="index" namespace="/" extends="struts-default">
<default-action-ref name="error"></default-action-ref>
<action name="error" class="cn.orlion.actions.StudentsAction" method="error">
<result>
/404.jsp
</result>
</action>
</package>
这样当访问不存在的action时就会请求设置的默认的action如:http://localhost:8080/Struts2Demo/dawdawdawdawdawd.action