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。
解决方法
在一个典型的Spring MVC应用程序中,最少可以有两个上下文:应用程序上下文和servlet上下文。上下文是一种配置。应用程序上下文保存与整个应用程序相关的配置,而servlet上下文只保留与您的servlet相关的配置。因此,servlet上下文是应用程序上下文的子代,并且可以引用应用程序上下文中的任何实体。反之亦然。
在你的报价中,
@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.
@EnableTransactionManagement在@ComponentScan注释中声明的包中的bean中查找@Transactional,但仅在它们定义的上下文(@Configuration)中。因此,如果您的DispatcherServlet具有WebApplicationContext(这是一个servlet上下文),则@EnableTransactionManagement将在您在该上下文(@Configuration类)中告诉组件扫描的类中寻找@Transactional。
@Configuration @EnableTransactionManagement @ComponentScan(basePackages = "my.servlet.package") public class ServletContextConfiguration { // this will only find @Transactional annotations on classes in my.servlet.package package }
由于您的@Service类是应用程序上下文的一部分,因此如果要使这些事务处理事务,则需要使用@EnableTransactionManagement为应用程序上下文注释@Configuration类。
@Configuration @EnableTransactionManagement @ComponentScan(basePackages = "my.package.services") public class ApplicationContextConfiguration { // now this will scan your my.package.services package for @Transactional }
在实例化DispatcherServlet时,使用ContextLoaderListener和您的Servlet Context配置。 (See the javadoc为完整的基于java的配置,而不是xml,如果你还没有这样做)。
附录:@EnableTransactionManagement与< tx:annotation-driven />具有相同的行为。在java配置中。 Check here使用ContextLoaderListener与XML。