用jbiulder建了一个基于strust的web application,编译后放到tomcat的webapps\root目录下, 通过ie访问出现问题, 请问怎么解决?

type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception javax.servlet.ServletException: Cannot find ActionMappings or ActionFormBeans collection
org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:848)
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:781)
org.apache.jsp.strust.WebModule1.input_jsp._jspService(org.apache.jsp.strust.WebModule1.input_jsp:83)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:322)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
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:773)
org.apache.struts.taglib.html.FormTag.doStartTag(FormTag.java:481)
org.apache.jsp.strust.WebModule1.input_jsp._jspx_meth_html_form_0(org.apache.jsp.strust.WebModule1.input_jsp:135)
org.apache.jsp.strust.WebModule1.input_jsp._jspx_meth_html_html_0(org.apache.jsp.strust.WebModule1.input_jsp:110)
org.apache.jsp.strust.WebModule1.input_jsp._jspService(org.apache.jsp.strust.WebModule1.input_jsp:75)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:322)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
note The full stack trace of the root cause is available in the Apache Tomcat/5.5.9 logs.