hibernate - 用Spring的声明式事务，得到异常no transaction is in progressjava-PHP中文网问答

在进行Spring和hibernate的整合时，利用Spring的声明式事务管理，得到一个异常：no transaction is in progress
在网上查阅相关资料，发现有的需要加注解@Transactional，有的是因为加了两个实体管理类，但是都无法解决我的问题。
以下是相关代码：

bean.xml
<bean id="u" class="com.Spring.DAO.UserDAOMySQLimplement">
        <property name="sessionfactor" ref="SessionFactory"/>
    </bean>
     <bean id="LogDAO" class="com.Spring.DAO.LogDAOMySQLimplement">
        <property name="sessionfactor" ref="SessionFactory"/>
    </bean>
    <bean id="Service" class="com.Spring.Service.UserService">
        <property name="dao" ref="u"/>
        <property name="logdao" ref="LogDAO"/>
    </bean>
    <!-- 定义一个数据源 -->
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost/Spring"/>
        <property name="username" value="root"/>
        <property name="password" value="tiger"/>
    </bean>
    <bean id="SessionFactory" class="org.springframework.orm.hibernate5.LocalSessionFactoryBean">
          <property name="dataSource" ref="dataSource"/>
          <property name="annotatedClasses">
            <list>
                <value>com.Spring.Model.User</value>
                <value>com.Spring.Model.Log</value>
            </list>
          </property>
          <property name="hibernateProperties">
             <value>
                hibernate.dialect=org.hibernate.dialect.MySQLDialect
                hibernate.show_sql=true
              </value>
           </property>
    </bean>
    <tx:annotation-driven transaction-manager="txManager"/>        
    <bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>
    <tx:annotation-driven transaction-manager="txManager"/>

Service层

public class UserService {
    private UserDAO dao=null;
    private LogDAO logdao;
    public LogDAO getLogdao() {
        return logdao;
    }
    public void setLogdao(LogDAO logdao) {
        this.logdao = logdao;
    }
    @Transactional("txManager")
    public void add(User u){
        dao.add(u);
        Log log=new Log();
        log.setMsg("日志：成功存入用户");
        logdao.add(log);
    }
    public UserDAO getDao() {
        return dao;
    }
    public void setDao(UserDAO dao) {
        this.dao = dao;
    }

}

UserDAO层

   public class UserDAOMySQLimplement implements UserDAO {
    SessionFactory sessionfactor;            //定义一个sessionfactor,使用自动注入来初始化。
    public SessionFactory getSessionfactor() {
        return sessionfactor;
    }
    public void setSessionfactor(SessionFactory sessionfactor) {
        this.sessionfactor = sessionfactor;
    }
    //往数据库保存一条记录
    public void add(User u) {
        Session session=sessionfactor.getCurrentSession();
        session.save(u);        
    }

LogDAO层

      public class LogDAOMySQLimplement implements LogDAO {
    SessionFactory sessionfactor;            //定义一个sessionfactor,使用自动注入来初始化。
    public SessionFactory getSessionfactor() {
        return sessionfactor;
    }
    public void setSessionfactor(SessionFactory sessionfactor) {
        this.sessionfactor = sessionfactor;
    }
    //往数据库保存一条记录
    @Override
    public void add(Log log) {
        Session session=sessionfactor.getCurrentSession();
        session.save(log);    
    }
}

测试代码

   public void Test_add(){
        ApplicationContext context=new ClassPathXmlApplicationContext("beans.xml");
        User u=new User();
        u.setName("小明"); 
        UserService us=(UserService) context.getBean("Service");
        System.out.println(us.getClass());
        us.add(u);
        
    }

所用版本Spring4.3.4,hibernate5.2.5
想要完成的业务逻辑是往数据库插入一条User记录,并且往日志表插入一条日志。