The Struts dispatcher cannot be found. This is usually caused by using Struts tags without the...

异常信息：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.

问题描述: 在jsp页面中使用struts2.0标签,访问jsp页面时会出现异常.

web.xml部分配置文件:

<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>*.action</url-pattern>
  </filter-mapping>

问题原因:

如果想要在jsp文件中，采用 struts的tag，那么jsp必须是通过action跳转得到，也就是必须通过web.xml所配置的过滤器访问文件，否则会有异常。
解决办法：
方案一：将web.xml 的过滤器，从 *.action 修改为： /* 。

方案二：web.xml 中再添加一个filter 
 <filter-mapping> 
    <filter-name>struts2</filter-name> 
    <url-pattern>*.jsp</url-pattern> 
</filter-mapping> 
<filter-mapping>
  <filter-name>struts2</filter-name>
  <url-pattern>*.action</url-pattern>
  </filter-mapping>