关于Spring的3层托管设置问题

以为tomcat的报错！！
严重: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener
org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [com.shunshi.dao.impl.user.UserDAOImpl] for bean with name 'userDao' defined in ServletContext resource [/WEB-INF/applicationContext.xml]; nested exception is java.lang.ClassNotFoundException: com.shunshi.dao.impl.user.UserDAOImpl
Caused by: java.lang.ClassNotFoundException: com.shunshi.dao.impl.user.UserDAOImpl
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1645)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1491)
at org.springframework.util.ClassUtils.forName(ClassUtils.java:229)
at org.springframework.beans.factory.support.AbstractBeanDefinition.resolveBeanClass(AbstractBeanDefinition.java:327)
at org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1073)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:283)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:352)
at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:246)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:189)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:49)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4135)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4630)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:785)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:445)
at org.apache.catalina.core.StandardService.start(StandardService.java:519)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:710)
at org.apache.catalina.startup.Catalina.start(Catalina.java:581)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414)
2011-4-13 10:21:15 org.apache.catalina.core.StandardContext start
严重: Error listenerStart
2011-4-13 10:21:15 org.apache.catalina.core.StandardContext start
严重: Context [/mytest] startup failed due to previous errors
以下是Spring的配置！
<aop:config>
<aop:pointcut id="serviceOperation" expression="execution(* com.shunshi.service.impl.*.*.*(..))"/>
<aop:advisor advice-ref="txAdvice" pointcut-ref="serviceOperation"/>
</aop:config>
<!-- Dao层的托管 -->   <bean id="userDao" class="com.shunshi.dao.impl.user.UserDAOImpl">
  <property name="sessionFactory" ref="sessionFactory"/>
   </bean><!-- Service层的托管 -->   <bean id="userService" class="com.shunshi.service.impl.user.UserServiceImpl">
  <property name="userDao" ref="userDao"></property>
   </bean><!-- Action层的托管 -->   <bean id="userAction" class="com.shunshi.web.action.user.SaveUserAction" scope="prototype">
  <property name="userService" ref="userService" />
   </bean>
跪求高人指出错误问题！！