对于web MVC Spring应用程序应该@Transactional去控制器或服务？

这是我的web.xml：

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>Alpha v0.02</display-name>
  <servlet>
    <servlet-name>spring</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
  </servlet>

  <servlet-mapping>
    <servlet-name>spring</servlet-name>
    <url-pattern>*.htm</url-pattern>
  </servlet-mapping>

  <servlet-mapping>
    <servlet-name>spring</servlet-name>
    <url-pattern>*.json</url-pattern>
  </servlet-mapping>

  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>

这是我的application-context.xml定义一个spring调度程序servlet：

<?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:context="http://www.springframework.org/schema/context"
        xmlns:mvc="http://www.springframework.org/schema/mvc"
        xmlns:tx="http://www.springframework.org/schema/tx"
        xsi:schemaLocation="
            http://www.springframework.org/schema/tx
            http://www.springframework.org/schema/tx/spring-tx.xsd
            http://www.springframework.org/schema/beans    
            http://www.springframework.org/schema/beans/spring-beans.xsd
            http://www.springframework.org/schema/context 
            http://www.springframework.org/schema/context/spring-context.xsd
            http://www.springframework.org/schema/mvc 
            http://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <context:annotation-config />
    <mvc:annotation-driven />
    <tx:annotation-driven />

    <context:component-scan base-package="com.visitrend" />

    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/"/>
        <property name="suffix" value=".jsp"/>
    </bean>

     <bean id="dataSource"  class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
        <property name="driverClass" value="org.postgresql.Driver" />
        <property name="jdbcUrl" value="jdbc:postgresql://localhost:5432/postgres" />
        <property name="user" value="someuser" />
        <property name="password" value="somepasswd" />
    </bean>

    <bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="configLocation" value="classpath:test.hibernate.cfg.xml" />
    </bean>

    <bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager">
      <property name="dataSource" ref="dataSource" />
      <property name="sessionFactory" ref="sessionFactory" />
    </bean>    
</beans>

这是一个服务界面：

public interface LayerService {
    public void createLayer(Integer layerListID,Layer layer);
}

这是一个服务实现：

@Service
public class LayerServiceImpl implements LayerService {

    @Autowired
    public LayerDAO layerDAO;

    @Transactional
    @Override
    public void createLayer(Integer layerListID,Layer layer) {
        layerDAO.createLayer(layerListID,layer);
    }
}

这是我的控制器：

@Controller
public class MainController {

    @Autowired
    private LayerService layerService;

    @RequestMapping(value = "/addLayer.json",method = RequestMethod.POST)
    public @ResponseBody
    LayerListSetGroup addLayer(@RequestBody JSONLayerFactory request) {
        layerService.createLayer(request.getListId(),request.buildLayer());
        return layerService.readLayerListSetGroup(llsgID);
    }
}

Spring文档让我有点困惑。似乎表明使用WebApplicationContext意味着只有控制器将被调查@Transactional注释而不是服务。同时我看到了许多建议，使服务交易而不是控制器。我在考虑使用< context：component-scan base-package =“com ...”/>在我们上面的spring-servlet.xml中，它包括服务包意味着服务是上下文的一部分，因此将被“调查”用于事务注释。这是准确吗？

这是Spring文档blurb让我困惑：

@EnableTransactionManagement and only looks
for @Transactional on beans in the same application context they are
defined in. This means that,if you put annotation driven
configuration in a WebApplicationContext for a DispatcherServlet,it
only checks for @Transactional beans in your controllers,and not your
services.

此外，如果我将控制器方法定义为事务性，是否有任何性能影响或“坏”，并且在另一个类中调用事务方法？我的希望是没有，基于文档，但会喜欢验证。