#|16-Spring AOP源码分析-@EnableAspectJAutoProxy和AspectJAutoProxyRegistrar spring|java|后端|spring

@EnableAspectJAutoProxy **2）我们看到在我们配置类上加入了@EnableAspectJAutoProxy,我们着重来分析一下这个东东给我容器中添加了什么组件？
**2.1)我们发现@EnableAspectJAutoProxy上标注了一个@Import注解，通过前面的学习我们知道@Import可以给我们容器****中添加组件

@Target(ElementType.TYPE) @Retention(RetentionPolicy.RUNTIME) @Documented @Import(AspectJAutoProxyRegistrar.class) public @interface EnableAspectJAutoProxy {

AspectJAutoProxyRegistrar 【#|16-Spring AOP源码分析-@EnableAspectJAutoProxy和AspectJAutoProxyRegistrar】2.2)所以我们来分析AspectJAutoProxyRegistrar类是用来干什么的？
经过跟踪源代码我们发现,AspectJAutoProxyRegistrar实现了ImportBeanDefinitionRegistrar接口，我们以前学习过
凡是实现了*ImportBeanDefinitionRegistrar可以给我们容器中添加bean定义信息*
*作用:往容器中注册了一个名称叫org.springframework.aop.config.internalAutoProxyCreator*
? *类型为AnnotationAwareAspectJAutoProxyCreator 注解的apsectj自动代理创建器*

class AspectJAutoProxyRegistrar implements ImportBeanDefinitionRegistrar { @Override public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {//往容器中注册对应的 aspectj注解自动代理创建器 AopConfigUtils.registerAspectJAnnotationAutoProxyCreatorIfNecessary(registry); AnnotationAttributes enableAspectJAutoProxy = AnnotationConfigUtils.attributesFor(importingClassMetadata, EnableAspectJAutoProxy.class); if (enableAspectJAutoProxy.getBoolean("proxyTargetClass")) { AopConfigUtils.forceAutoProxyCreatorToUseClassProxying(registry); } if (enableAspectJAutoProxy.getBoolean("exposeProxy")) { AopConfigUtils.forceAutoProxyCreatorToExposeProxy(registry); } }}======================AopConfigUtils.registerAspectJAnnotationAutoProxyCreatorIfNecessary(registry); ====================== public static BeanDefinition registerAspectJAnnotationAutoProxyCreatorIfNecessary(BeanDefinitionRegistry registry) { return registerAspectJAnnotationAutoProxyCreatorIfNecessary(registry, null); } //注册一个AnnotationAwareAspectJAutoProxyCreator（注解适配的切面自动创建器） public static BeanDefinition registerAspectJAnnotationAutoProxyCreatorIfNecessary(BeanDefinitionRegistry registry, Object source) { return registerOrEscalateApcAsRequired(AnnotationAwareAspectJAutoProxyCreator.class, registry, source); } private static BeanDefinition registerOrEscalateApcAsRequired(Class cls, BeanDefinitionRegistry registry, Object source) { Assert.notNull(registry, "BeanDefinitionRegistry must not be null"); //判断容器中有没有org.springframework.aop.config.internalAutoProxyCreator 名称的bean定义 if (registry.containsBeanDefinition(AUTO_PROXY_CREATOR_BEAN_NAME)) { BeanDefinition apcDefinition = registry.getBeanDefinition(AUTO_PROXY_CREATOR_BEAN_NAME); if (!cls.getName().equals(apcDefinition.getBeanClassName())) { int currentPriority = findPriorityForClass(apcDefinition.getBeanClassName()); int requiredPriority = findPriorityForClass(cls); if (currentPriority < requiredPriority) { apcDefinition.setBeanClassName(cls.getName()); } } return null; }//容器中没有那么就注册一个名称叫org.springframework.aop.config.internalAutoProxyCreator类型是AnnotationAwareAspectJAutoProxyCreator的bean定义 RootBeanDefinition beanDefinition = new RootBeanDefinition(cls); beanDefinition.setSource(source); beanDefinition.getPropertyValues().add("order", Ordered.HIGHEST_PRECEDENCE); beanDefinition.setRole(BeanDefinition.ROLE_INFRASTRUCTURE); registry.registerBeanDefinition(AUTO_PROXY_CREATOR_BEAN_NAME, beanDefinition); return beanDefinition; }