Spring 注解编程IOC源码

1. Spring 注解编程IOC涉及的主要类
2. Spring 注解编程IOC源码分析

Spring 注解编程IOC涉及的主要类

AnnotationConfigApplicationContext

org.springframework.context.annotation.AnnotationConfigApplicationContext

注解的启动容器入口

AbstractApplicationContext

org.springframework.context.support.AbstractApplicationContext

容器的执行方法抽象类

AnnotatedBeanDefinitionReader

org.springframework.context.annotation.AnnotatedBeanDefinitionReader

注解Bean定义的读取器

ClassPathBeanDefinitionScanner

org.springframework.context.annotation.ClassPathBeanDefinitionScanner

类路径的Bean定义扫描

DefaultListableBeanFactory

org.springframework.beans.factory.support.DefaultListableBeanFactory

BeanFactory的工厂，主要的

PostProcessorRegistrationDelegate

org.springframework.context.support.PostProcessorRegistrationDelegate

后置处理的委派类

AnnotationConfigUtils

org.springframework.context.annotation.AnnotationConfigUtils

注解配置的工具类

AbstractBeanFactory

org.springframework.beans.factory.support.AbstractBeanFactory

抽象BeanFactory

AbstractAutowireCapableBeanFactory

org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory

自动注入的抽象BeanFactory

Spring 注解编程IOC源码分析

构造器

创建BeanFactory–DefaultListableBeanFactory

创建reader–AnnotatedBeanDefinitionReader

ConditionEvaluator @Conditional鉴定器

AnnotationConfigUtils.registerAnnotationConfigProcessors(this.registry)

注册注解配置的后置处理器

1. 赋值DependencyComparator – AnnotationAwareOrderComparator
2. 赋值AutowireCandidateResolver – ContextAnnotationAutowireCandidateResolver
3. 注册org.springframework.context.annotation.internalConfigurationAnnotationProcessor – ConfigurationClassPostProcessor
4. 注册org.springframework.context.annotation.internalAutowiredAnnotationProcessor – AutowiredAnnotationBeanPostProcessor
5. 注册org.springframework.context.annotation.internalCommonAnnotationProcessor – CommonAnnotationBeanPostProcessor
6. 注册org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor – PersistenceAnnotationBeanPostProcessor
7. 注册org.springframework.context.event.internalEventListenerProcessor – EventListenerMethodProcessor
8. 注册org.springframework.context.event.internalEventListenerFactory – DefaultEventListenerFactory

创建scanner –hhh

1. registerDefaultFilters 注册默认的扫描拦截
   • Component
   • ManagedBean
   • Named
2. setEnvironment(environment) 赋予环境
3. setResourceLoader(resourceLoader) 赋予资源加载器

register(annotatedClasses)

注册方法的配置类

doRegisterBean()

注册实际干活的方法

1. ConditionEvaluator 鉴定Condition条件
   • 判断@Conditional
   • 获取Condition条件集合并进行排序
   • 循环判断上述Condition条件
2. AnnotationConfigUtils.processCommonDefinitionAnnotations(abd)
   • @Lazy
   • @Primary
   • @DependsOn
   • @Role
   • @Description
3. Qualifier进行处理Primary、Lazy以及其他
4. BeanDefinitionCustomizer#customize BeanDefinition自定义器处理
5. 注册BeanDefinitionHolder的BeanDefinition

scan(basePackages)

扫描包路径

refresh()

据我们所知IOC容器的主要方法是通过refresh方法进行刷新启动，容器刷新创建

prepareRefresh()

准备容器的刷新工作

1. 设置标志位closed、active

   this.closed.set(false);
   this.active.set(true);

2. initPropertySources()

   初始化属性配置文件，未进行实现，需要子类自行实现

3. getEnvironment().validateRequiredProperties()

obtainFreshBeanFactory()

告诉子类刷新内部的BeanFactory

1. refreshBeanFactory()

   通过AtomicBoolean.compareAndSet(false, true)来控制一个BeanFactory,并设置一个序列化的ID值，若是需要的话，可以通过这个序列化ID来发序列化为BeanFactory

2. 返回构造器初始化的BeanFactory

prepareBeanFactory(beanFactory)

上下文中准备使用的BeanFactory

1. 赋值BeanClassLoader

2. 赋值BeanExpressionResolver – StandardBeanExpressionResolver

3. 添加PropertyEditorRegistrar – ResourceEditorRegistrar

4. 添加BeanPostProcessor – ApplicationContextAwareProcessor,实现Aware接口方法的赋值

   EnvironmentAware、EmbeddedValueResolverAware、ResourceLoaderAware、ApplicationEventPublisherAware、MessageSourceAware、ApplicationContextAware

5. 去掉上面的依赖接口，避免重复调用

6. 注册依赖类BeanFactory、ResourceLoader、ApplicationEventPublisher、ApplicationContext

7. 添加BeanPostProcessor – ApplicationListenerDetector 处理ApplicationListener事件监听

8. 如果包含loadTimeWeaver这个Bean，添加对应的BeanPostProcessor – LoadTimeWeaverAwareProcessor以及赋值TempClassLoader – ContextTypeMatchClassLoader

9. 注册环境信息的Bean

environment – StandardEnvironment

systemProperties – getEnvironment().getSystemProperties()

systemEnvironment – getEnvironment().getSystemEnvironment()

postProcessBeanFactory(beanFactory)

子类在上下文中后置处理BeanFactory

invokeBeanFactoryPostProcessors(beanFactory)

调用BeanFactoryPostProcesser

PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(beanFactory, getBeanFactoryPostProcessors());

后置处理器的委派处理类

1. BeanDefinitionRegistry的处理
   • 处理上面添加的BeanFactoryPostProcessor的BeanDefinitionRegistryPostProcessor#postProcessBeanDefinitionRegistry(registry)
   • 获取BeanFatory中所有的BeanDefinitionRegistryPostProcessor
   • 实现PriorityOrdered的接口的BeanDefinitionRegistryPostProcessor排序并执行BeanDefinitionRegistryPostProcessor#postProcessBeanDefinitionRegistry(registry）
   • 实现Ordered的接口的BeanDefinitionRegistryPostProcessor排序并执行BeanDefinitionRegistryPostProcessor#postProcessBeanDefinitionRegistry(registry）
   • 剩下的BeanDefinitionRegistryPostProcessor排序并执行BeanDefinitionRegistryPostProcessor#postProcessBeanDefinitionRegistry(registry）
   • 执行所有的BeanDefinitionRegistryPostProcessor#postProcessBeanFactory(beanFactory)
   • 执行除BeanDefinitionRegistryPostProcessor的BeanDefinitionRegistry#postProcessBeanFactory(beanFactory)
2. 直接执行除BeanDefinitionRegistryPostProcessor的BeanDefinitionRegistry#postProcessBeanFactory(beanFactory)，与上述1互斥
3. BeanFactoryPostProcessor的处理
   • 实现PriorityOrdered的BeanFactoryPostProcessor排序并执行BeanFactoryPostProcessor.postProcessBeanFactory(beanFactory)
   • 实现Ordered的BeanFactoryPostProcessor排序并执行BeanFactoryPostProcessor.postProcessBeanFactory(beanFactory)
   • 剩下的BeanFactoryPostProcessor执行BeanFactoryPostProcessor.postProcessBeanFactory(beanFactory)
   • 清除后置处理器可能改变的原元数据信息

重置了添加对应的BeanPostProcessor – LoadTimeWeaverAwareProcessor以及赋值TempClassLoader – ContextTypeMatchClassLoader

registerBeanPostProcessors(beanFactory)

注册拦截Bean创建的BeanPostProcessor

PostProcessorRegistrationDelegate.registerBeanPostProcessors(beanFactory, this);

1. 添加BeanPostProcessor – BeanPostProcessorChecker
2. 实现PriorityOrdered的除掉MergedBeanDefinitionPostProcessor的BeanPostProcessor排序并进行注册
3. 实现Ordered的除掉MergedBeanDefinitionPostProcessor的BeanPostProcessor排序并进行注册
4. 剩下的除掉MergedBeanDefinitionPostProcessor的BeanPostProcessor进行注册
5. MergedBeanDefinitionPostProcessor排序并注册
6. 添加了一个BeanPostProcessor – ApplicationListenerDetector

initMessageSource()

初始化MessageSource

1. 判断可有messageSource的Bean
   • 有，判断当前messageSource是否是HierarchicalMessageSource,是的话赋值ParentMessageSource
   • 没有，注册messageSource – DelegatingMessageSource,并赋值ParentMessageSource

initApplicationEventMulticaster()

初始化ApplicationEvent派发器，注册applicationEventMulticaster – SimpleApplicationEventMulticaster

onRefresh()

模板方法来添加上下文刷新工作，子类进行实现

registerListeners()

注册监听器

1. ApplicationEvent派发器添加事件
2. ApplicationEvent派发器添加事件Bean
3. 派发早期处理事件

finishBeanFactoryInitialization(beanFactory)

完成BeanFactory的实例化

1. 初始化ConversionService
2. 注册EmbeddedValueResolver
3. 初始化LoadTimeWeaverAware接口的Bean
4. 完成非惰性加载的单实例Bean初始化
   • 触发非惰性加载的单实例Bean初始化getBean()
   • 若是SmartInitializingSingleton触发回调smartSingleton.afterSingletonsInstantiated()

getBean(beanName) – doGetBean()

获取Bean的实例

1. 从FactoryBean中获取Bean

2. 判断parentBeanFactory以及parentBeanFactory包含当前Bean，从parentBeanFactory进行获取

3. 循环获取DependsOn的Bean

4. 创建Bean – createBean(beanName, mbd, args)

   • 准备方法的覆盖重写 – prepareMethodOverrides()

   • 尝试让BeanPostProcessor返回一个代理Bean– resolveBeforeInstantiation(beanName, mbdToUse)

   • 真正创建Bean实例 – doCreateBean(beanName, mbdToUse, args),Bean的整个生命周期

     • createBeanInstance(beanName, mbd, args) 实例化

     • applyMergedBeanDefinitionPostProcessors(mbd, beanType, beanName)

       MergedBeanDefinitionPostProcessor.postProcessMergedBeanDefinition(mbd, beanType, beanName)方法处理

     • populateBean(beanName, mbd, instanceWrapper) 属性赋值，包含自动注入

     • initializeBean(beanName, exposedObject, mbd) 初始化Bean

       • invokeAwareMethods(beanName, bean) 调用aware接口方法

       • applyBeanPostProcessorsBeforeInitialization(wrappedBean, beanName)

         BeanPostProcessor.postProcessBeforeInitialization()前置方法

       • invokeInitMethods(beanName, wrappedBean, mbd)

         • 先调用InitializingBean.afterPropertiesSet()
         • 反射调用init-method的方法

       • applyBeanPostProcessorsAfterInitialization(wrappedBean, beanName)

         BeanPostProcessor.postProcessAfterInitialization 后置方法

     • 检查循环依赖

     • registerDisposableBeanIfNecessary(beanName, bean, mbd) 注册Bean的销毁方法

       org.springframework.beans.factory.support.DisposableBeanAdapter

5. 检查必须的类型是否匹配

finishRefresh()

1. clearResourceCaches(); 清楚资源缓存

2. initLifecycleProcessor() 初始化LifecycleProcessor

   注册lifecycleProcessor–DefaultLifecycleProcessor

3. getLifecycleProcessor().onRefresh()调用LifecycleProcessor#onRefresh()方法

4. 发布ContextRefreshedEvent

5. LiveBeansView注册ApplicationContext