The Struts dispatcher cannot be found. 使用struts标签时该报错的解决方案

错误场景:

条件1:struts2核心过滤器过滤url-pattern为*.action

条件2:JSP页面中使用了struts标签

条件3:通过url直接访问该JSP页面

错误提示:

The Struts dispatcher cannot be found.  This is usually caused by using Struts tags without the associated filter. Struts tags are only usable when the request has passed through its servlet filter, which initializes the Struts dispatcher needed for this tag. - [unknown location]

解决方案:

错误提示说的很清楚:该错误通常是由使用struts标签时未关联核心过滤器所致.Struts标签只有当请求通过核心过滤器时才能生效,因为Struts标签需要核心过滤器对其进行初始化.

1.将web.xml中核心过滤器的映射改为/*

<filter>
  <filter-name>struts2</filter-name>
  <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
</filter>
  
<filter-mapping>
  <filter-name>struts2</filter-name>
  <url-pattern>/*</url-pattern>
</filter-mapping>

 

2.或者为核心过滤器追加对*.jsp的过滤

<filter-mapping>
  <filter-name>struts2</filter-name>
  <url-pattern>*.action</url-pattern>
</filter-mapping>
  
<filter-mapping>
  <filter-name>struts2</filter-name>
  <url-pattern>*.jsp</url-pattern>
</filter-mapping>