<bean id="BaseDao" class="com.tsinghua.dao.impl.BaseDaoimpl">
         <property name="sessionFactory"><ref bean="sessionFactory" /></property>
     </bean>
      <bean id="BaseService" class="com.tsinghua.service.BaseServiceimpl">
        <property name="basedao"><ref bean="BaseDao" /></property>
     </bean>
     <bean id="UserService" class="com.tsinghua.service.UserServiceimpl" parent="BaseService">
     <bean id="AService" class="com.tsinghua.service.AServiceimpl" parent="BaseService">
     <bean id="BService" class="com.tsinghua.service.BserServiceimpl" parent="BaseService">

     </bean>