Transaction is not being rollbacked in spring - spring

Question

While issuing two inserts, if second one is failed the transaction should be rollback but this is not happening in my case, following are the details of configuration!
<bean id="sessionFactory"
class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="annotatedClasses">
<list>
<value>com.xyz.model.Merchant</value>
....
</list>
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">${hibernate.dialect}</prop>
<prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
<prop key="hibernate.format_sql">${hibernate.format_sql}</prop>
</props>
</property>
</bean>
<bean id="transactionManager"
class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
<tx:advice id="txAdvice">
<tx:attributes>
<tx:method name="get*" read-only="true"/>
<tx:method name="save*" propagation="REQUIRED"/>
<tx:method name="modify*" propagation="REQUIRED"/>
</tx:attributes>
</tx:advice>
<aop:config>
<aop:pointcut id="allServices"
expression="execution(*
com.xyz.services.DemoApiServiceImpl.saveEmployee(..))"/>
<aop:advisor advice-ref="txAdvice" pointcut-ref="allServices"/>
</aop:config>
<aop:aspectj-autoproxy/>
and these are the code details;
#Service
#Transactional
public class DemoApiServiceImpl implements DemoApiService {
#Override
//#Transactional( propagation = Propagation.REQUIRED, rollbackFor = Exception.class )
public boolean saveEmployee(Employee employee) throws Exception {
Boolean flag = Boolean.FALSE;
flag = demoApiDao.saveOrUpdateEmployee(employee);
if(flag)
//generating exception so that above insert should rollback!
throw new Exception("ok");
if(!CollectionUtils.isEmpty(employee.getUsers())) {
Users user = (Users) employee.getUsers().toArray()[0];
//sendEmail(user,EmailType.USER_SIGN_UP.name(),Constants.MAIL_SUBJECT_ACTIVATION_LINK);
UsersDto usersDto = new UsersDto();
usersDto.setActivationCode(user.getActivationCode());
String emailText = Utils.createEmailText(usersDto, EmailType.USER_SIGN_UP.name());
Utils.sendEmail(user.getUsername(), Constants.FROM_EMAIL, Constants.MAIL_SUBJECT_ACTIVATION_LINK, emailText);
}
return flag;
}
}
unfortunately the transaction is not being rollbacked, I have generated exception manually to reverse the transaction.
Any help in this regards?
TA.