请问如何解决references unmapped class hibernate，急！！！谢了先

<?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" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd" version="2.4">
  <display-name>Jointsoft EPG System</display-name>
  <filter>
    <filter-name>DataProviderFilter</filter-name>
    <filter-class>com.jointsoft.epg.jdo.DataProviderFilter</filter-class>
  </filter>
  <filter-mapping>
    <filter-name>DataProviderFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>
  <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>2</param-value>
    </init-param>
    <load-on-startup>2</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>action</servlet-name>
    <url-pattern>*.do</url-pattern>
  </servlet-mapping>
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
  <jsp-config>
    <taglib>
      <taglib-uri>/tags/struts-html</taglib-uri>
      <taglib-location>/WEB-INF/struts-html.tld</taglib-location>
    </taglib>
    <taglib>
      <taglib-uri>/tags/struts-logic</taglib-uri>
      <taglib-location>/WEB-INF/struts-logic.tld</taglib-location>
    </taglib>
    <taglib>
      <taglib-uri>/tags/struts-bean</taglib-uri>
      <taglib-location>/WEB-INF/struts-bean.tld</taglib-location>
    </taglib>
    <taglib>
      <taglib-uri>/tags/app</taglib-uri>
      <taglib-location>/WEB-INF/app.tld</taglib-location>
    </taglib>
  </jsp-config>
  <error-page>
    <exception-type>java.lang.Exception</exception-type>
    <location>/Error.jsp</location>
  </error-page>
</web-app>