2

我正在尝试使用 AspectJ,我的项目运行正常。但是当我尝试使用 AspectJ 时,注入无法正常工作。如果我不使用 AspectJ,它会再次起作用。

我包含在我的 pom.xml 中

<dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjrt</artifactId>
            <version>1.6.11</version>
        </dependency>

        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.6.11</version>
        </dependency>

我的配置文件:

   <aop:aspectj-autoproxy />
    <tx:annotation-driven />

    <!-- Database Configuration -->
    <import resource="../database/DataSource.xml"/> 

        <!-- Auto scan the components -->
    <context:component-scan base-package="es.rooms.db.spring.dao" />
    <context:component-scan base-package="es.rooms.util" />

    <!-- Aspect -->
    <bean id="logAspect" class="es.rooms.util.LoggingAspect" />

我正在对我的课程使用注释:

@Repository("RoomDAO")
public class RoomDAO extends JdbcDaoSupport implements IRoomDAO{

    @Autowired
    private PlayerDAO playerDAO;

我不知道我是否必须扫描我的 AspectJ 课程,反正我做了。我试图将 PlayerDAO 标记为 required=false,并且我可以检查是否调用了 LoggingAspect,但是当 RoomDAO 将调用 PlayerDAO 时,我得到了 NullPointException。为什么我使用 AspectJ 时不能 spring 注入 PlayerDAO?

@Aspect
public class LoggingAspect {



    @Before("execution(* es.rooms.db.spring.dao.*.*(..))")
    public void logBefore(JoinPoint joinPoint) {

        System.out.println("!!!!!!!!!!!!!!logBefore() is running! ->" + joinPoint.getSignature().getName());        
        System.out.println("******");
    }

这是错误:

04-jun-2013 11:36:46 org.springframework.beans.factory.support.DefaultSingletonBeanRegistry destroySingletons
INFO: Destroying singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@61acfa31: defining beans [org.springframework.aop.config.internalAutoProxyCreator,org.springframework.transaction.annotation.AnnotationTransactionAttributeSource#0,org.springframework.transaction.interceptor.TransactionInterceptor#0,org.springframework.transaction.config.internalTransactionAdvisor,org.springframework.beans.factory.config.PropertyPlaceholderConfigurer#0,dataSource,playerDAO,RoomDAO,userDAO,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,manageRooms,messagesGcm,transactionManager,logAspect,org.springframework.context.annotation.ConfigurationClassPostProcessor$ImportAwareBeanPostProcessor#0]; root of factory hierarchy
Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'RoomDAO': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private es.rooms.db.spring.dao.PlayerDAO es.rooms.db.spring.dao.RoomDAO.playerDAO; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No matching bean of type [es.rooms.db.spring.dao.PlayerDAO] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:287)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1106)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:585)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:913)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:464)
    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
    at es.rooms.server.RoomsServer.<init>(RoomsServer.java:23)
    at es.rooms.server.RoomsServer.main(RoomsServer.java:61)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private es.rooms.db.spring.dao.PlayerDAO es.rooms.db.spring.dao.RoomDAO.playerDAO; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No matching bean of type [es.rooms.db.spring.dao.PlayerDAO] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:506)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:284)
    ... 14 more

谢谢你。

更新:

我修复了它添加

<aop:aspectj-autoproxy proxy-target-class="true"/>

但是,我不知道为什么会这样,如果有人可以解释我,我很感激。

4

2 回答 2

2

来自http://docs.spring.io/spring/docs/3.1.1.RELEASE/spring-framework-reference/html/aop.html

Spring AOP 使用 JDK 动态代理或 CGLIB 为给定的目标对象创建代理。(当您有选择时,首选 JDK 动态代理)。

如果要代理的目标对象至少实现一个接口,则将使用 JDK 动态代理。目标类型实现的所有接口都将被代理。如果目标对象没有实现任何接口,那么将创建一个 CGLIB 代理。

如果您想强制使用 CGLIB 代理(例如,代理为目标对象定义的每个方法,而不仅仅是那些由其接口实现的方法),您可以这样做。.... 要强制使用 CGLIB 代理,请将元素的 proxy-target-class 属性的值设置为 true:

因此,您已经为所有类打开了 CGLIB 代理。阅读整个页面以获取更多信息 - 这是使用 Spring AOP 的重要背景信息。当您使用 CGLIB 时会发生一些有趣且不同的事情(所有内容都记录在上面的链接中) - 如果可以,最好遵循 Spring 约定。即如果你自动装配一个类,给它一个接口和一个空构造函数。

于 2014-01-29T01:28:34.567 回答
0

我错误地在使用的一个单元测试中得到了相同的错误消息:

@Autowire
ServiceImpl service;

代替

@Autowire
Service service;

(ServiceImpl 实现 Service 的地方)。在我添加aop:aspectj-autoproxy之前,它一直在使用任一版本

于 2014-08-01T12:24:03.000 回答