<tx:advice id="txAdvice" transaction-manager="txManager">
         <tx:attributes>
            <tx:method name="save*" propagation="REQUIRED"/>
            <tx:method name="del*" propagation="REQUIRED"/>
            <tx:method name="update*" propagation="REQUIRED"/>
            <tx:method name="*" read-only="true"/>  这里有read-only
        </tx:attributes>
</tx:advice>

@Transactional(readOnly=true)   hibernate注解的read-only
public class QuestionOptionService {}