大家好，我是structs的初学者，第一个调试程序报错，一直发现不了错误，请各位帮帮忙！报错信息是：
javax.servlet.ServletException: Cannot find ActionMappings or ActionFormBeans collection
org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:846)
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:779)
org.apache.jsp.login_jsp._jspService(login_jsp.java:85)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:324)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
root cause
javax.servlet.jsp.JspException: Cannot find ActionMappings or ActionFormBeans collection
org.apache.struts.taglib.html.FormTag.lookup(FormTag.java:798)
org.apache.struts.taglib.html.FormTag.doStartTag(FormTag.java:506)
org.apache.jsp.login_jsp._jspx_meth_html_form_0(login_jsp.java:101)
org.apache.jsp.login_jsp._jspService(login_jsp.java:75)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:324)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
我的配置文件写法如下：
web.xml:
<?xml version= "1.0 " encoding= "UTF-8 "?>
<web-app xmlns= "http://java.sun.com/xml/ns/j2ee " xmlns:xsi= "http://www.w3.org/2001/XMLSchema-instance " version= "2.4 " xsi:schemaLocation= "http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd ">
<servlet>
<servlet-name> action </servlet-name>
<servlet-class> org.apache.struts.action.ActionServlet </servlet-class>
<init-param>
<param-name> config </param-name>
<param-value> /WEB-INF/struts-config.xml </param-value>
</init-param>
<init-param>
<param-name> debug </param-name>
<param-value> 3 </param-value>
</init-param>
<init-param>
<param-name> detail </param-name>
<param-value> 3 </param-value>
</init-param>
<load-on-startup> 0 </load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name> action </servlet-name>
<url-pattern> *.do </url-pattern>
</servlet-mapping>
</web-app>
structs-config.xml:
<?xml version= "1.0 " encoding= "UTF-8 "?>