.The Struts dispatcher cannot be found. This is usually caused by using Struts

1.The Struts dispatcher cannot be found.  This is usually caused by using Struts tags without the associated filter. Strut   
2.s tags are only usable when the request has passed through its servlet filter, which initializes the Struts dispatcher n   

3.eeded for this tag. - [unknown location] 

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：web.xml 中添加一个filter 

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