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

这是一个运行时异常,在struts2 的 struts.xml配置文件中  <action> 的class 指向Action类是否配置正确,如果引用的命名空间与实际对象不符   就会导致这种异常问题

Caused by: 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]

at org.apache.struts2.views.jsp.TagUtils.getStack(TagUtils.java:60)

at org.apache.struts2.views.jsp.StrutsBodyTagSupport.getStack(StrutsBodyTagSupport.java:44)

at org.apache.struts2.views.jsp.ComponentTagSupport.doStartTag(ComponentTagSupport.java:48)

at org.apache.jsp.fail.failed_jsp._jspx_meth_s_005fproperty_005f0(failed_jsp.java:288)

at org.apache.jsp.fail.failed_jsp._jspService(failed_jsp.java:241)

at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)

... 20 more

这些问题 希望能够帮助struts2 的初学者们