Spring 注解编程IOC涉及的主要类
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

赋值DependencyComparator -- AnnotationAwareOrderComparator
赋值AutowireCandidateResolver -- ContextAnnotationAutowireCandidateResolver
注册org.springframework.context.annotation.internalConfigurationAnnotationProcessor -- ConfigurationClassPostProcessor
注册org.springframework.context.annotation.internalAutowiredAnnotationProcessor -- AutowiredAnnotationBeanPostProcessor
注册org.springframework.context.annotation.internalCommonAnnotationProcessor -- CommonAnnotationBeanPostProcessor
注册org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor -- PersistenceAnnotationBeanPostProcessor
注册org.springframework.context.event.internalEventListenerProcessor -- EventListenerMethodProcessor
注册org.springframework.context.event.internalEventListenerFactory -- DefaultEventListenerFactory

创建`scanner` --`hhh`

registerDefaultFilters 注册默认的扫描拦截
- Component
- ManagedBean
- Named
setEnvironment(environment) 赋予环境
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

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
AnnotationConfigUtils.processCommonDefinitionAnnotations(abd)
- @Lazy
- @Primary
- @DependsOn
- @Role
- @Description
Qualifier进行处理Primary、Lazy以及其他
BeanDefinitionCustomizer#customize BeanDefinition自定义器处理
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

设置标志位closed、active

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

initPropertySources()

初始化属性配置文件，未进行实现，需要子类自行实现
getEnvironment().validateRequiredProperties()

`obtainFreshBeanFactory()`

告诉子类刷新内部的BeanFactory

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
返回构造器初始化的BeanFactory

`prepareBeanFactory(beanFactory)`

上下文中准备使用的BeanFactory

赋值BeanClassLoader
赋值BeanExpressionResolver -- StandardBeanExpressionResolver
添加PropertyEditorRegistrar -- ResourceEditorRegistrar
添加BeanPostProcessor -- ApplicationContextAwareProcessor,实现Aware接口方法的赋值

EnvironmentAware、EmbeddedValueResolverAware、ResourceLoaderAware、ApplicationEventPublisherAware、MessageSourceAware、ApplicationContextAware
去掉上面的依赖接口，避免重复调用
注册依赖类BeanFactory、ResourceLoader、ApplicationEventPublisher、ApplicationContext
添加BeanPostProcessor -- ApplicationListenerDetector 处理ApplicationListener事件监听
如果包含loadTimeWeaver这个Bean，添加对应的BeanPostProcessor -- LoadTimeWeaverAwareProcessor以及赋值TempClassLoader -- ContextTypeMatchClassLoader
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

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)
直接执行除BeanDefinitionRegistryPostProcessor的BeanDefinitionRegistry#postProcessBeanFactory(beanFactory)，与上述1互斥
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);`

添加BeanPostProcessor -- BeanPostProcessorChecker
实现PriorityOrdered的除掉MergedBeanDefinitionPostProcessor的BeanPostProcessor排序并进行注册
实现Ordered的除掉MergedBeanDefinitionPostProcessor的BeanPostProcessor排序并进行注册
剩下的除掉MergedBeanDefinitionPostProcessor的BeanPostProcessor进行注册
MergedBeanDefinitionPostProcessor排序并注册
添加了一个BeanPostProcessor -- ApplicationListenerDetector

`initMessageSource()`

初始化MessageSource

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

ApplicationEvent派发器添加事件
ApplicationEvent派发器添加事件Bean
派发早期处理事件

`finishBeanFactoryInitialization(beanFactory)`

完成BeanFactory的实例化

初始化ConversionService
注册EmbeddedValueResolver
初始化LoadTimeWeaverAware接口的Bean
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

从FactoryBean中获取Bean
判断parentBeanFactory以及parentBeanFactory包含当前Bean，从parentBeanFactory进行获取
循环获取DependsOn的Bean
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
检查必须的类型是否匹配

`finishRefresh()`

clearResourceCaches(); 清楚资源缓存
initLifecycleProcessor() 初始化LifecycleProcessor

注册lifecycleProcessor--DefaultLifecycleProcessor
getLifecycleProcessor().onRefresh()调用LifecycleProcessor#onRefresh()方法
发布ContextRefreshedEvent
LiveBeansView注册ApplicationContext

AnnotationConfigApplicationContext​

AbstractApplicationContext​

AnnotatedBeanDefinitionReader​

ClassPathBeanDefinitionScanner​

DefaultListableBeanFactory​

PostProcessorRegistrationDelegate​

AnnotationConfigUtils​

AbstractBeanFactory​

AbstractAutowireCapableBeanFactory​

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)​

创建scanner --hhh​

register(annotatedClasses)​

doRegisterBean()​

scan(basePackages)​

refresh()​

prepareRefresh()​

obtainFreshBeanFactory()​

prepareBeanFactory(beanFactory)​

postProcessBeanFactory(beanFactory)​

invokeBeanFactoryPostProcessors(beanFactory)​

PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(beanFactory, getBeanFactoryPostProcessors());​

registerBeanPostProcessors(beanFactory)​

PostProcessorRegistrationDelegate.registerBeanPostProcessors(beanFactory, this);​

initMessageSource()​

initApplicationEventMulticaster()​

onRefresh()​

registerListeners()​

finishBeanFactoryInitialization(beanFactory)​

getBean(beanName) -- doGetBean()​

finishRefresh()​