Unknow Entity : Hibernate

最近做一个java ee的项目。从别人那儿接手的。
他的model是myeclipse反向工程自动生成的。
结果出了这么个异常：
org.springframework.orm.hibernate3.HibernateSystemException: Unknown entity不知道我的配置文件是不是哪儿出了问题？
请各位大虾帮忙看看~~。applicationContext.xml如下：
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
                     http://www.springframework.org/schema/beans/spring-beans.xsd 
                     http://www.springframework.org/schema/tx 
                     http://www.springframework.org/schema/tx/spring-tx.xsd 
                     http://www.springframework.org/schema/aop 
                     http://www.springframework.org/schema/aop/spring-aop.xsd">    
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName">
<value>com.mysql.jdbc.Driver</value>
</property>
<property name="url">
<value>jdbc:mysql://localhost:3306/sms</value>
</property>
<property name="username">
<value>root</value>
</property>
<property name="password">
<value>root</value>
</property>
</bean>
<bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
    <property name="dataSource">
        <ref bean="dataSource" />
    </property>  
    <property name="hibernateProperties">
        <props>
           <prop key="hibernate.dialect">
               org.hibernate.dialect.MySQLDialect
           </prop>
        </props>
    </property> 
    <property name="mappingResources">
        <list>
            <value>com/model/Users.hbm.xml</value>
            
            <!-- 这里可以添加所有需要的POJ映射文件 -->
            
        </list>
    </property> 
</bean>

<bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
    <property name="sessionFactory" ref="sessionFactory" />
</bean>
    
    <bean id="transactionInterceptor" class="org.springframework.transaction.interceptor.TransactionInterceptor">
        <!-- 事务拦截器bean需要依赖注入的一个事务管理器 -->
        <property name="transactionManager" ref="transactionManager" />
        <property name="transactionAttributes">
           <!-- 下面定义的是事物传播属性 -->
           <props>
              <prop key="insert*">PROPAGATION_REQUIRED</prop> 
              <prop key="update*">PROPAGATION_REQUIRED</prop> 
              <prop key="save*">PROPAGATION_REQUIRED</prop> 
              <prop key="find*">PROPAGATION_SUPPORTS,readOnly</prop> 
              <prop key="get*">PROPAGATION_REQUIRED,readOnly</prop>
              <prop key="del*">PROPAGATION_REQUIRED,readOnly</prop>
              <prop key="*">PROPAGATION_REQUIRED</prop>
           </props>
        </property>
    </bean>
    
    <!-- 定义BeanNameAutoProxyCreator来简化事务配置-->
    <bean class="org.springframework.aop.framework.autoproxy.BeanNameAutoProxyCreator">
       <!-- 定义所有需要自动创建事务代理的bean -->
       <property name="beanNames">
          <list>
             <value>UserDAO</value>
             <value>UserService</value>
          </list>
          
          <!-- 这里可以增加其他需要自动创建事务代理的bean -->
          
       </property>
       <!-- 定义 BeanNameAutoProxyCreator所需的事务拦截器-->
       <property name="interceptorNames">
          <list>
             <value>transactionInterceptor</value>
             
              <!-- 这里可以增加其他新的Interceptor -->
             
          </list>
       </property>
    </bean>
    <bean id="userService" class="com.service.impl.UserServiceImpl">
       <property name="userDao" ref="userDao"></property>    
    </bean>
    <bean id="memoService" class="com.service.impl.MemoServiceImpl">
     <property name="memoDao" ref="memoDao"></property>
    </bean>
    
    <bean id="userDao" class="com.dao.impl.UserDAOImpl">
       <property name="sessionFactory">
           <ref bean="sessionFactory" />
       </property>
    </bean>
    <bean id="memoDao" class="com.dao.impl.MemoDAOImpl">
     <property name="sessionFactory">
     <ref bean="sessionFactory" />
     </property>
    </bean>
    
    <bean name="login" class="com.action.LoginAction" scope="prototype" autowire="byName" />
    <bean id="saveUserAction" class="com.action.SaveUserAction" scope="prototype">
       <property name="service" ref="userService"></property>
    </bean>
    <bean name="listUserAction" class="com.action.ListUserAction" scope="prototype">
       <property name="service" ref="userService"></property>
    </bean>
    <bean name="updatePUserAction" class="com.action.UpdatePUser" scope="prototype">
       <property name="service" ref="userService"></property>
    </bean>
    <bean name="updateUserAction" class="com.action.UpdateUserAction" scope="prototype">
       <property name="service" ref="userService"></property>
    </bean>
    <bean name="removeUserAction" class="com.action.RemoveUserAction" scope="prototype">
       <property name="service" ref="userService"></property>
    </bean>    
    <bean name="addMemoAction" class="com.action.AddMemoAction" scope="prototype" autowire="byType">
     <property name="service" ref="memoService"></property>
    </bean>
    <bean name="deleteMemoAction" class="com.action.DeleteMemoAction" scope="prototype" autowire="byType">
     <property name="service" ref="memoService"></property>
    </bean>
    <bean name="updateMemoAction" class="com.action.UpdateMemoAction" scope="prototype" autowire="byType">
     <property name="service" ref="memoService"></property>
    </bean>
    <bean name="queryMemoAction" class="com.action.QueryMemoAction" scope="prototype" autowire="byType">
     <property name="service" ref="memoService"></property>
    </bean>
</beans>Memo.hbm.xml如下：
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- 
    Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping>
    <class name="com.model.Memo" table="memo" catalog="sms">
        <composite-id name="id" class="com.model.MemoId">
            <key-property name="id" type="java.lang.Integer">
                <column name="id" />
            </key-property>
            <key-property name="title" type="java.lang.String">
                <column name="title" length="20" />
            </key-property>
            <key-property name="content" type="java.lang.String">
                <column name="content" length="60" />
            </key-property>
            <key-property name="remindTime" type="java.lang.String">
                <column name="remindTime" length="8" />
            </key-property>
            <key-property name="remindMode" type="java.lang.Integer">
                <column name="remindMode" />
            </key-property>
            <key-property name="creator" type="java.lang.String">
                <column name="creator" length="30" />
            </key-property>
            <key-property name="flag" type="java.lang.String">
                <column name="flag" length="50" />
            </key-property>
            <key-property name="isRead" type="java.lang.Integer">
                <column name="isRead" />
            </key-property>
        </composite-id>
    </class>
</hibernate-mapping>
hibernate.cfg.xml如下:
<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
          "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
          "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"><!-- Generated by MyEclipse Hibernate Tools.                   -->
<hibernate-configuration> <session-factory>

<mapping resource="./Users.hbm.xml" />
<mapping resource="model/Users.hbm.xml" />
<mapping resource="com/model/Memo.hbm.xml" />

</session-factory>

</hibernate-configuration>
麻烦各位大虾帮帮忙，看看到底是哪里出问题了纠结了很久了。也把save方法改成save（"com.model.Memo",memo）了。还是不行。
一直出现 Unknow Entity
蛋疼啊。