spring5.1.x源码解析之三(new ApplicationContext())

/*
		设置文件路径
		刷新上下文
	 */
	public ClassPathXmlApplicationContext(
			String[] configLocations, boolean refresh, @Nullable ApplicationContext parent)
			throws BeansException {

		super(parent);
		//设置文件路径
		setConfigLocations(configLocations);
		if (refresh) {
			//刷新上下文
			refresh();
		}
	}

	//解析路径
	public void setConfigLocations(@Nullable String... locations) {
		if (locations != null) {
			Assert.noNullElements(locations, "Config locations must not be null");
			this.configLocations = new String[locations.length];
			for (int i = 0; i < locations.length; i++) {
				//解析路径,如果存在${var},会搜寻匹配的系统变量并替换
				this.configLocations[i] = resolvePath(locations[i]).trim();
			}
		}
		else {
			this.configLocations = null;
		}
	}

/*
	准备刷新上下文环境
	初始化beanFactory
	对BeanFactory进行各种功能填充
	子类覆盖方法做额外处理
	执行所有BeanFactoryPostProcessors
	注册BeanPostProcessors
	国际化处理
	初始化应用消息广播器
	留给子类来初始化其他bean
	注册监听器
	初始化非惰性的剩下的单实例
	完成刷新过程

	异常处理
		销毁已经创建的单例bean,避免资源悬空
		标记没有正在刷新状态
		抛出异常
	重置缓存
	 */
	@Override
	public void refresh() throws BeansException, IllegalStateException {
		synchronized (this.startupShutdownMonitor) {
			// Prepare this context for refreshing.
			//准备刷新上下文环境,如系统属性或者环境变量准备以及验证,还有监听器初始化
			prepareRefresh();

			// Tell the subclass to refresh the internal bean factory.
			//初始化beanFactory,并进行XML读取,加载BeanDefinition
			ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();

			// Prepare the bean factory for use in this context.
			//对BeanFactory进行各种功能填充
			//如@Qualifier与@Autowired
			prepareBeanFactory(beanFactory);

			try {
				// Allows post-processing of the bean factory in context subclasses.
				//子类覆盖方法做额外处理
				postProcessBeanFactory(beanFactory);


				/*
				BeanFactoryPostProcessors和BeanPostProcessors区别
				BeanPostProcessors并不需要马山调用,所以不需要考虑硬编码方式
				而BeanFactoryPostProcessors之所以考虑硬编码是因为不仅要实现注册功能，还要实现对后处理器的激活操作，所以需要载入配置中的定义,并进行激活
				 */

				// Invoke factory processors registered as beans in the context.
				//激活各种BeanFactory处理器
				//BeanFactoryPostProcessor作用域容器级,仅仅对容器中的bean进行后置处理,如propertyPlaceholderConfig,继承order可实现排序调用功能
				//BeanFactoryPostProcessor可以修改实际的bean实例
				invokeBeanFactoryPostProcessors(beanFactory);

				// Register bean processors that intercept bean creation.
				//注册拦截bean创建的bean处理器,这里只是注册,真正调用在getBean
				registerBeanPostProcessors(beanFactory);
				// Initialize message source for this context.
				//为上下文初始化message源,即国际化处理
				initMessageSource();

				// Initialize event multicaster for this context.
				//初始化应用消息广播器,并放入applicationEventMulticaster，bean中。
				//SimpleApplicationEventMulticaster.multicastEvent:调用这个发送
				initApplicationEventMulticaster();

				// Initialize other special beans in specific context subclasses.
				//留给子类来初始化其他bean
				onRefresh();

				// Check for listener beans and register them.
				//在所有注册的bean中查找Listener bean,注册到消息广播器中
				registerListeners();

				// Instantiate all remaining (non-lazy-init) singletons.
				//初始化剩下的非延迟初始化单实例
				finishBeanFactoryInitialization(beanFactory);

				// Last step: publish corresponding event.
				//完成刷新过程,通知生命周期处理器LifecycleProcessor刷新过程,同时发出ContextRefreshEvent通知别人
				finishRefresh();
			}

			catch (BeansException ex) {
				if (logger.isWarnEnabled()) {
					logger.warn("Exception encountered during context initialization - " +
							"cancelling refresh attempt: " + ex);
				}

				// Destroy already created singletons to avoid dangling resources.
				//销毁已经创建的单例bean,避免资源悬空
				destroyBeans();

				// Reset 'active' flag.
				//标记没有正在刷新状态
				cancelRefresh(ex);

				// Propagate exception to caller.
				throw ex;
			}

			finally {
				// Reset common introspection caches in Spring's core, since we
				// might not ever need metadata for singleton beans anymore...
				//重置Spring核心中的常见内省缓存，因为可能不再需要singleton bean的元数据了。。。
				resetCommonCaches();
			}
		}
	}

/*
	设置上下文状态
	留给子类初始化上下文环境变量,包括系统变量
	验证需要的属性文件是否都已经放入环境中
	在刷新之前初始或重置监听器
	在多主机设置之前发布的ApplicationEvents。
	 */
	protected void prepareRefresh() {
		// Switch to active.
		this.startupDate = System.currentTimeMillis();
		this.closed.set(false);//标记上下文不是关闭状态
		this.active.set(true);//标记当前上下文活跃状态

		if (logger.isDebugEnabled()) {
			if (logger.isTraceEnabled()) {
				logger.trace("Refreshing " + this);
			}
			else {
				logger.debug("Refreshing " + getDisplayName());
			}
		}

		// Initialize any placeholder property sources in the context environment.
		//留给子类覆盖
		//在上下文环境中初始化任何占位符属性源。
		initPropertySources();

		// Validate that all properties marked as required are resolvable:
		// see ConfigurablePropertyResolver#setRequiredProperties
		//验证需要的属性文件是否都已经放入环境中,当检测占位符资源无法解析,异常
		getEnvironment().validateRequiredProperties();

		// Store pre-refresh ApplicationListeners...
		//在刷新之前初始化本地ApplicationListeners
		if (this.earlyApplicationListeners == null) {
			this.earlyApplicationListeners = new LinkedHashSet<>(this.applicationListeners);
		}
		else {
			// Reset local application listeners to pre-refresh state.
			//在刷新之前重置本地应用监听器
			this.applicationListeners.clear();
			this.applicationListeners.addAll(this.earlyApplicationListeners);
		}

		// Allow for the collection of early ApplicationEvents,
		// to be published once the multicaster is available...
		//在多主机设置之前发布的ApplicationEvents。
		this.earlyApplicationEvents = new LinkedHashSet<>();
	}

	protected ConfigurableListableBeanFactory obtainFreshBeanFactory() {
		//初始化BeanFactory,并进行XML文件读取,并将得到的BeanFactory记录在当前实体的属性中
		refreshBeanFactory();
		//返回当前实体的beanFactory属性
		return getBeanFactory();
	}

/*
	销毁存在的BeanFactory
	创建DefaultListableBeanFactory
	序列化指定值
	设置BeanFactory相关属性
	加载BeanDefinition
	使用全局变量记录BeanFactory实例
	 */
	@Override
	protected final void refreshBeanFactory() throws BeansException {
		//是否有BeanFactory
		if (hasBeanFactory()) {
			//销毁所有bean
			destroyBeans();
			//清除所有BeanFactory
			closeBeanFactory();
		}
		try {
			//创建DefaultListableBeanFactory
			DefaultListableBeanFactory beanFactory = createBeanFactory();
			//为了序列化指定id,如果需要的话让这个BeanFactory从id反序列化到BeanFactory对象
			beanFactory.setSerializationId(getId());
			//设置BeanFactory相关属性,包括是否允许覆盖同名称的不同定义的对象以及循环依赖
			customizeBeanFactory(beanFactory);
			//加载BeanDefinition,进行XML文件读取及解析,
			loadBeanDefinitions(beanFactory);
			synchronized (this.beanFactoryMonitor) {
				//使用全局变量记录BeanFactory实例
				this.beanFactory = beanFactory;
			}
		}
		catch (IOException ex) {
			throw new ApplicationContextException("I/O error parsing bean definition source for " + getDisplayName(), ex);
		}
	}

/*
	设置是否允许覆盖同名称的不同定义的对象
	设置是否允许bean之间存在循环依赖
	一般子类继承修改这2值
	 */
	protected void customizeBeanFactory(DefaultListableBeanFactory beanFactory) {
		//一般子类继承修改这2值
		//是否允许覆盖同名称的不同定义的对象
		if (this.allowBeanDefinitionOverriding != null) {
			beanFactory.setAllowBeanDefinitionOverriding(this.allowBeanDefinitionOverriding);
		}
		//是否允许bean之间存在循环依赖
		if (this.allowCircularReferences != null) {
			beanFactory.setAllowCircularReferences(this.allowCircularReferences);
		}
	}

/*
	为指定beanFactory创建XmlBeanDefinitionReader
	设置环境变量
	设置资源加载器
	设置xml解析器
	是否关闭XML验证
	加载BeanDefinitions
	 */
	@Override
	protected void loadBeanDefinitions(DefaultListableBeanFactory beanFactory) throws BeansException, IOException {
		// Create a new XmlBeanDefinitionReader for the given BeanFactory.
		//为指定beanFactory创建XmlBeanDefinitionReader
		XmlBeanDefinitionReader beanDefinitionReader = new XmlBeanDefinitionReader(beanFactory);

		// Configure the bean definition reader with this context's
		// resource loading environment.
		//设置环境变量
		beanDefinitionReader.setEnvironment(this.getEnvironment());
		//设置资源加载器
		beanDefinitionReader.setResourceLoader(this);
		//设置xml解析器
		//BeansDtdResolver:使用默认的DTD解析
		//PluggableSchemaResolver:设置META-INF/spring.schemas路径,该文件有xsd路径地址
		beanDefinitionReader.setEntityResolver(new ResourceEntityResolver(this));

		// Allow a subclass to provide custom initialization of the reader,
		// then proceed with actually loading the bean definitions.
		//对beanDefinitionReader设置，可以覆盖
		//是否关闭XML验证,如XSD,DTD之类的验证
		initBeanDefinitionReader(beanDefinitionReader);
		//加载BeanDefinitions,内部调用XML解析
		loadBeanDefinitions(beanDefinitionReader);
	}

/*
	解析Resource
	 */
	protected void loadBeanDefinitions(XmlBeanDefinitionReader reader) throws BeansException, IOException {
		Resource[] configResources = getConfigResources();
		if (configResources != null) {
			reader.loadBeanDefinitions(configResources);
		}
		String[] configLocations = getConfigLocations();
		if (configLocations != null) {
			reader.loadBeanDefinitions(configLocations);
		}
	}

/*
	设置加载器
	设置表达式语言处理器
	设置默认属性编辑器
	添加BeanPostProcessor,对其他资源获取处理
	设置忽略资源获取自动装配的接口
	设置自动装配的特殊规则
	添加BeanPostProcessor,销毁前回调
	增加AspectJ支持
	设置默认系统环境bean
	 */
	protected void prepareBeanFactory(ConfigurableListableBeanFactory beanFactory) {
		// Tell the internal bean factory to use the context's class loader etc.
		//设置加载器
		beanFactory.setBeanClassLoader(getClassLoader());
		//设置表达式语言处理器,spring3.X新增，可以使用#{bean.xxx}调用相关属性值,支持SPEL表达式
		//DefaultListableBeanFactory.doResolveDependency 调用 evaluateBeanDefinitionString
		beanFactory.setBeanExpressionResolver(new StandardBeanExpressionResolver(beanFactory.getBeanClassLoader()));
		//设置默认属性编辑器
		//AbstractBeanFactory.initBeanWrapper会使用编辑器,对应AbstractBeanFactory.propertyEditorRegistrars
		//registerBeanPostProcessors会注册所有自定义编辑器,对应AbstractBeanFactory.customEditors
		beanFactory.addPropertyEditorRegistrar(new ResourceEditorRegistrar(this, getEnvironment()));

		// Configure the bean factory with context callbacks.
		//添加BeanPostProcessor,主要对一些Aware资源获取的补充
		beanFactory.addBeanPostProcessor(new ApplicationContextAwareProcessor(this));

		//设置忽略了几个自动装配的接口,因为继承这些Aware接的,将获得资源,ApplicationContextAwareProcessor注入了这些资源
		//而且他主要是资源获取,不提供注入作用
		beanFactory.ignoreDependencyInterface(EnvironmentAware.class);
		beanFactory.ignoreDependencyInterface(EmbeddedValueResolverAware.class);
		beanFactory.ignoreDependencyInterface(ResourceLoaderAware.class);
		beanFactory.ignoreDependencyInterface(ApplicationEventPublisherAware.class);
		beanFactory.ignoreDependencyInterface(MessageSourceAware.class);
		beanFactory.ignoreDependencyInterface(ApplicationContextAware.class);

		// BeanFactory interface not registered as resolvable type in a plain factory.
		// MessageSource registered (and found for autowiring) as a bean.
		//设置自动装配的特殊规则,依赖类型如果是key,直接赋值value
		beanFactory.registerResolvableDependency(BeanFactory.class, beanFactory);
		beanFactory.registerResolvableDependency(ResourceLoader.class, this);
		beanFactory.registerResolvableDependency(ApplicationEventPublisher.class, this);
		beanFactory.registerResolvableDependency(ApplicationContext.class, this);

		// Register early post-processor for detecting inner beans as ApplicationListeners.
		//添加BeanPostProcessor,主要用于销毁前回调
		beanFactory.addBeanPostProcessor(new ApplicationListenerDetector(this));

		// Detect a LoadTimeWeaver and prepare for weaving, if found.
		//增加AspectJ支持 LTW,静态注入aop
		//LoadTimeWeaverBeanDefinitionParser.getBeanClassName注入了bean
		if (beanFactory.containsBean(LOAD_TIME_WEAVER_BEAN_NAME)) {
			beanFactory.addBeanPostProcessor(new LoadTimeWeaverAwareProcessor(beanFactory));
			// Set a temporary ClassLoader for type matching.
			beanFactory.setTempClassLoader(new ContextTypeMatchClassLoader(beanFactory.getBeanClassLoader()));
		}

		// Register default environment beans.
		//设置默认系统环境bean
		if (!beanFactory.containsLocalBean(ENVIRONMENT_BEAN_NAME)) {
			beanFactory.registerSingleton(ENVIRONMENT_BEAN_NAME, getEnvironment());
		}
		if (!beanFactory.containsLocalBean(SYSTEM_PROPERTIES_BEAN_NAME)) {
			beanFactory.registerSingleton(SYSTEM_PROPERTIES_BEAN_NAME, getEnvironment().getSystemProperties());
		}
		if (!beanFactory.containsLocalBean(SYSTEM_ENVIRONMENT_BEAN_NAME)) {
			beanFactory.registerSingleton(SYSTEM_ENVIRONMENT_BEAN_NAME, getEnvironment().getSystemEnvironment());
		}
	}

自定义属性编辑器传送门

/*
	移除,重新添加
	初始化bean前回调
	销毁前回调bean
	 */
	@Override
	public void addBeanPostProcessor(BeanPostProcessor beanPostProcessor) {
		Assert.notNull(beanPostProcessor, "BeanPostProcessor must not be null");
		// Remove from old position, if any
		//移除,重新添加
		this.beanPostProcessors.remove(beanPostProcessor);
		// Track whether it is instantiation/destruction aware
		//初始化bean前回调
		if (beanPostProcessor instanceof InstantiationAwareBeanPostProcessor) {
			this.hasInstantiationAwareBeanPostProcessors = true;
		}
		//销毁前回调bean
		if (beanPostProcessor instanceof DestructionAwareBeanPostProcessor) {
			this.hasDestructionAwareBeanPostProcessors = true;
		}
		// Add to end of list
		this.beanPostProcessors.add(beanPostProcessor);
	}

	/*
	主要获取资源
	 */
	public Object postProcessBeforeInitialization(final Object bean, String beanName) throws BeansException {
		AccessControlContext acc = null;

		if (System.getSecurityManager() != null &&
				(bean instanceof EnvironmentAware || bean instanceof EmbeddedValueResolverAware ||
						bean instanceof ResourceLoaderAware || bean instanceof ApplicationEventPublisherAware ||
						bean instanceof MessageSourceAware || bean instanceof ApplicationContextAware)) {
			acc = this.applicationContext.getBeanFactory().getAccessControlContext();
		}

		if (acc != null) {
			AccessController.doPrivileged((PrivilegedAction<Object>) () -> {
				invokeAwareInterfaces(bean);
				return null;
			}, acc);
		}
		else {
			//实现这些Aware,将获得某些资源
			invokeAwareInterfaces(bean);
		}

		return bean;
	}

	private void invokeAwareInterfaces(Object bean) {
		if (bean instanceof Aware) {
			if (bean instanceof EnvironmentAware) {
				((EnvironmentAware) bean).setEnvironment(this.applicationContext.getEnvironment());
			}
			if (bean instanceof EmbeddedValueResolverAware) {
				((EmbeddedValueResolverAware) bean).setEmbeddedValueResolver(this.embeddedValueResolver);
			}
			if (bean instanceof ResourceLoaderAware) {
				((ResourceLoaderAware) bean).setResourceLoader(this.applicationContext);
			}
			if (bean instanceof ApplicationEventPublisherAware) {
				((ApplicationEventPublisherAware) bean).setApplicationEventPublisher(this.applicationContext);
			}
			if (bean instanceof MessageSourceAware) {
				((MessageSourceAware) bean).setMessageSource(this.applicationContext);
			}
			if (bean instanceof ApplicationContextAware) {
				((ApplicationContextAware) bean).setApplicationContext(this.applicationContext);
			}
		}
	}

/*
	执行BeanFactoryPostProcessors
	对LTW的支持
	 */
	protected void invokeBeanFactoryPostProcessors(ConfigurableListableBeanFactory beanFactory) {
		//执行BeanFactoryPostProcessors
		//getBeanFactoryPostProcessors里面的BeanFactoryPostProcessor元素由addBeanFactoryPostProcessor执行的时候添加
		PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(beanFactory, getBeanFactoryPostProcessors());

		// Detect a LoadTimeWeaver and prepare for weaving, if found in the meantime
		// (e.g. through an @Bean method registered by ConfigurationClassPostProcessor)
		//对LTW的支持
		if (beanFactory.getTempClassLoader() == null && beanFactory.containsBean(LOAD_TIME_WEAVER_BEAN_NAME)) {
			beanFactory.addBeanPostProcessor(new LoadTimeWeaverAwareProcessor(beanFactory));
			beanFactory.setTempClassLoader(new ContextTypeMatchClassLoader(beanFactory.getBeanClassLoader()));
		}
	}

/*
	对BeanDefinitionRegistry类型的处理
		遍历所有硬编码注册的beanFactoryPostProcessors
			当为BeanDefinitionRegistryPostProcessor类型
				则执行postProcessBeanDefinitionRegistry
				并添加注册处理器集合
			不符合直接添加常规后置处理器
	
		遍历配置文件注入的BeanDefinitionRegistryPostProcessor
			保存继承PriorityOrdered排序接口的对象
		按照PriorityOrdered排序当前处理器
		添加所有的当前注册处理器到注册处理器中
		当前处理器执行执行postProcessBeanDefinitionRegistry方法
		清空当前注册处理器
	
		遍历配置文件注入的BeanDefinitionRegistryPostProcessor
			保存继承Ordered排序接口的对象
		按照Ordered排序当前处理器
		添加所有的当前注册处理器到注册处理器中
		当前处理器执行执行postProcessBeanDefinitionRegistry方法
		清空当前注册处理器
	
		循环遍历以及调用postProcessBeanDefinitionRegistry方法
		...
		调用所有的继承了BeanDefinitionRegistryPostProcessor的postProcessBeanFactory方法
	调用传来的postProcessBeanFactory的postProcessBeanFactory方法
	获取所有继承了BeanFactoryPostProcessor的接口,并分别排序,和无序调用
	清除缓存的合并bean定义
 */
	public static void invokeBeanFactoryPostProcessors(
			ConfigurableListableBeanFactory beanFactory, List<BeanFactoryPostProcessor> beanFactoryPostProcessors) {

		// Invoke BeanDefinitionRegistryPostProcessors first, if any.
		Set<String> processedBeans = new HashSet<>();

		//对BeanDefinitionRegistry类型的处理
		if (beanFactory instanceof BeanDefinitionRegistry) {
			BeanDefinitionRegistry registry = (BeanDefinitionRegistry) beanFactory;
			//记录通过硬编码方式注册的BeanFactoryPostProcessor
			List<BeanFactoryPostProcessor> regularPostProcessors = new ArrayList<>();
			//记录通过硬编码方式注册的BeanDefinitionRegistryPostProcessor
			List<BeanDefinitionRegistryPostProcessor> registryProcessors = new ArrayList<>();

			for (BeanFactoryPostProcessor postProcessor : beanFactoryPostProcessors) {
				//对于BeanDefinitionRegistryPostProcessor类型,在beanFactoryPostProcessor的基础上还有自己定义的方法,需要先调用
				if (postProcessor instanceof BeanDefinitionRegistryPostProcessor) {
					BeanDefinitionRegistryPostProcessor registryProcessor =
							(BeanDefinitionRegistryPostProcessor) postProcessor;
					//执行postProcessBeanDefinitionRegistry方法
					registryProcessor.postProcessBeanDefinitionRegistry(registry);
					registryProcessors.add(registryProcessor);
				}
				else {
					//记录常规beanFactoryPostProcessor
					regularPostProcessors.add(postProcessor);
				}
			}

			// Do not initialize FactoryBeans here: We need to leave all regular beans
			// uninitialized to let the bean factory post-processors apply to them!
			// Separate between BeanDefinitionRegistryPostProcessors that implement
			// PriorityOrdered, Ordered, and the rest.
			//配置文件注入的BeanDefinitionRegistryPostProcessor
			List<BeanDefinitionRegistryPostProcessor> currentRegistryProcessors = new ArrayList<>();

			// First, invoke the BeanDefinitionRegistryPostProcessors that implement PriorityOrdered.
			//按照优先级排序
			String[] postProcessorNames =
					beanFactory.getBeanNamesForType(BeanDefinitionRegistryPostProcessor.class, true, false);
			for (String ppName : postProcessorNames) {
				//ppName对应的class是否是PriorityOrdered的子类
				if (beanFactory.isTypeMatch(ppName, PriorityOrdered.class)) {
					currentRegistryProcessors.add(beanFactory.getBean(ppName, BeanDefinitionRegistryPostProcessor.class));
					processedBeans.add(ppName);
				}
			}
			//按照PriorityOrdered排序当前处理器
			sortPostProcessors(currentRegistryProcessors, beanFactory);
			//添加所有的当前注册处理器到注册处理器中
			registryProcessors.addAll(currentRegistryProcessors);
			//当前处理器执行执行postProcessBeanDefinitionRegistry方法
			invokeBeanDefinitionRegistryPostProcessors(currentRegistryProcessors, registry);
			//清空当前注册处理器
			currentRegistryProcessors.clear();

			// Next, invoke the BeanDefinitionRegistryPostProcessors that implement Ordered.
			//按照Ordered排序
			postProcessorNames = beanFactory.getBeanNamesForType(BeanDefinitionRegistryPostProcessor.class, true, false);
			for (String ppName : postProcessorNames) {
				if (!processedBeans.contains(ppName) && beanFactory.isTypeMatch(ppName, Ordered.class)) {
					currentRegistryProcessors.add(beanFactory.getBean(ppName, BeanDefinitionRegistryPostProcessor.class));
					processedBeans.add(ppName);
				}
			}
			sortPostProcessors(currentRegistryProcessors, beanFactory);
			registryProcessors.addAll(currentRegistryProcessors);
			invokeBeanDefinitionRegistryPostProcessors(currentRegistryProcessors, registry);
			currentRegistryProcessors.clear();

			// Finally, invoke all other BeanDefinitionRegistryPostProcessors until no further ones appear.
			//无序，直接调用
			boolean reiterate = true;
			while (reiterate) {
				reiterate = false;
				postProcessorNames = beanFactory.getBeanNamesForType(BeanDefinitionRegistryPostProcessor.class, true, false);
				for (String ppName : postProcessorNames) {
					if (!processedBeans.contains(ppName)) {
						currentRegistryProcessors.add(beanFactory.getBean(ppName, BeanDefinitionRegistryPostProcessor.class));
						processedBeans.add(ppName);
						reiterate = true;
					}
				}
				sortPostProcessors(currentRegistryProcessors, beanFactory);
				registryProcessors.addAll(currentRegistryProcessors);
				invokeBeanDefinitionRegistryPostProcessors(currentRegistryProcessors, registry);
				currentRegistryProcessors.clear();
			}

			// Now, invoke the postProcessBeanFactory callback of all processors handled so far.
			//调用所有的继承了postProcessBeanFactory的postProcessBeanFactory方法
			//硬编码设置的BeanFactoryPostProcessors
			invokeBeanFactoryPostProcessors(registryProcessors, beanFactory);
			//配置的BeanFactoryPostProcessors
			invokeBeanFactoryPostProcessors(regularPostProcessors, beanFactory);
		}

		else {
			// Invoke factory processors registered with the context instance.
			//调用所有的继承了postProcessBeanFactory的postProcessBeanFactory方法
			invokeBeanFactoryPostProcessors(beanFactoryPostProcessors, beanFactory);
		}

		// Do not initialize FactoryBeans here: We need to leave all regular beans
		// uninitialized to let the bean factory post-processors apply to them!
		//对于配置中读取的BeanFactoryPostProcessor的处理,实际从RootBeanDefinition获取类型匹配
		String[] postProcessorNames =
				beanFactory.getBeanNamesForType(BeanFactoryPostProcessor.class, true, false);

		// Separate between BeanFactoryPostProcessors that implement PriorityOrdered,
		// Ordered, and the rest.
		List<BeanFactoryPostProcessor> priorityOrderedPostProcessors = new ArrayList<>();
		List<String> orderedPostProcessorNames = new ArrayList<>();
		List<String> nonOrderedPostProcessorNames = new ArrayList<>();
		//对后处理器进行分类
		for (String ppName : postProcessorNames) {
			if (processedBeans.contains(ppName)) {
				// skip - already processed in first phase above
				//已经处理过
			}
			else if (beanFactory.isTypeMatch(ppName, PriorityOrdered.class)) {
				priorityOrderedPostProcessors.add(beanFactory.getBean(ppName, BeanFactoryPostProcessor.class));
			}
			else if (beanFactory.isTypeMatch(ppName, Ordered.class)) {
				orderedPostProcessorNames.add(ppName);
			}
			else {
				nonOrderedPostProcessorNames.add(ppName);
			}
		}

		// First, invoke the BeanFactoryPostProcessors that implement PriorityOrdered.
		//按照优先级排序
		sortPostProcessors(priorityOrderedPostProcessors, beanFactory);
		invokeBeanFactoryPostProcessors(priorityOrderedPostProcessors, beanFactory);

		// Next, invoke the BeanFactoryPostProcessors that implement Ordered.
		//按照order排序调用
		List<BeanFactoryPostProcessor> orderedPostProcessors = new ArrayList<>();
		for (String postProcessorName : orderedPostProcessorNames) {
			orderedPostProcessors.add(beanFactory.getBean(postProcessorName, BeanFactoryPostProcessor.class));
		}
		sortPostProcessors(orderedPostProcessors, beanFactory);
		invokeBeanFactoryPostProcessors(orderedPostProcessors, beanFactory);

		// Finally, invoke all other BeanFactoryPostProcessors.
		//无序，直接调用
		List<BeanFactoryPostProcessor> nonOrderedPostProcessors = new ArrayList<>();
		for (String postProcessorName : nonOrderedPostProcessorNames) {
			nonOrderedPostProcessors.add(beanFactory.getBean(postProcessorName, BeanFactoryPostProcessor.class));
		}
		invokeBeanFactoryPostProcessors(nonOrderedPostProcessors, beanFactory);

		// Clear cached merged bean definitions since the post-processors might have
		// modified the original metadata, e.g. replacing placeholders in values...
		//清除缓存的合并bean定义，因为后处理器可能已修改原始元数据，例如替换值中的占位符。。。
		//清空已经标记(alreadyCreated)创建好的Bean,  markBeanAsCreated方法标记创建的
		beanFactory.clearMetadataCache();
	}

/*
	同上invokeBeanFactoryPostProcessors
	但不同的是,这里主要是注册,而且添加了ApplicationListenerDetector
	而上面的只会执行,而不会注册,因为生命周期不同
	 */
	public static void registerBeanPostProcessors(
			ConfigurableListableBeanFactory beanFactory, AbstractApplicationContext applicationContext) {

		//获取所有继承了BeanPostProcessor的names
		String[] postProcessorNames = beanFactory.getBeanNamesForType(BeanPostProcessor.class, true, false);

		// Register BeanPostProcessorChecker that logs an info message when
		// a bean is created during BeanPostProcessor instantiation, i.e. when
		// a bean is not eligible for getting processed by all BeanPostProcessors.
		int beanProcessorTargetCount = beanFactory.getBeanPostProcessorCount() + 1 + postProcessorNames.length;
		/*
		BeanPostProcessorChecker：普通信息打印
		当spring配置中的后处理器还没有被注册就已经开始了bean的初始化时
		便会打印BeanPostProcessorChecker设定信息
		 */
		beanFactory.addBeanPostProcessor(new BeanPostProcessorChecker(beanFactory, beanProcessorTargetCount));

		// Separate between BeanPostProcessors that implement PriorityOrdered,
		// Ordered, and the rest.
		//使用PriorityOrdered保证顺序
		List<BeanPostProcessor> priorityOrderedPostProcessors = new ArrayList<>();
		//MergedBeanDefinitionPostProcessor
		List<BeanPostProcessor> internalPostProcessors = new ArrayList<>();
		//使用Ordered保证顺序
		List<String> orderedPostProcessorNames = new ArrayList<>();
		//无序
		List<String> nonOrderedPostProcessorNames = new ArrayList<>();
		for (String ppName : postProcessorNames) {
			if (beanFactory.isTypeMatch(ppName, PriorityOrdered.class)) {
				BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
				priorityOrderedPostProcessors.add(pp);
				if (pp instanceof MergedBeanDefinitionPostProcessor) {
					//重复添加priorityOrderedPostProcessors和internalPostProcessors,在后续做了校验处理，所以不会重复添加
					//为了分类层次更加明显估计
					internalPostProcessors.add(pp);
				}
			}
			else if (beanFactory.isTypeMatch(ppName, Ordered.class)) {
				orderedPostProcessorNames.add(ppName);
			}
			else {
				nonOrderedPostProcessorNames.add(ppName);
			}
		}

		// First, register the BeanPostProcessors that implement PriorityOrdered.
		//注册所有实现priorityOrderedPostProcessors的BeanPostProcessors
		sortPostProcessors(priorityOrderedPostProcessors, beanFactory);
		registerBeanPostProcessors(beanFactory, priorityOrderedPostProcessors);

		// Next, register the BeanPostProcessors that implement Ordered.
		//注册所有实现Ordered的BeanPostProcessors
		List<BeanPostProcessor> orderedPostProcessors = new ArrayList<>();
		for (String ppName : orderedPostProcessorNames) {
			BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
			orderedPostProcessors.add(pp);
			if (pp instanceof MergedBeanDefinitionPostProcessor) {
				internalPostProcessors.add(pp);
			}
		}
		sortPostProcessors(orderedPostProcessors, beanFactory);
		registerBeanPostProcessors(beanFactory, orderedPostProcessors);

		// Now, register all regular BeanPostProcessors.
		//注册所有无序的BeanPostProcessors
		List<BeanPostProcessor> nonOrderedPostProcessors = new ArrayList<>();
		for (String ppName : nonOrderedPostProcessorNames) {
			BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
			nonOrderedPostProcessors.add(pp);
			if (pp instanceof MergedBeanDefinitionPostProcessor) {
				internalPostProcessors.add(pp);
			}
		}
		registerBeanPostProcessors(beanFactory, nonOrderedPostProcessors);

		// Finally, re-register all internal BeanPostProcessors.
		//注册所有MergedBeanDefinitionPostProcessor类型的BeanPostProcessors,并非重复注册
		sortPostProcessors(internalPostProcessors, beanFactory);
		registerBeanPostProcessors(beanFactory, internalPostProcessors);

		// Re-register post-processor for detecting inner beans as ApplicationListeners,
		// moving it to the end of the processor chain (for picking up proxies etc).
		//添加ApplicationListener探测器
		beanFactory.addBeanPostProcessor(new ApplicationListenerDetector(applicationContext));
	}

添加internalPostProcessors的时候会重复添加priorityOrderedPostProcessors

/*
	移除,避免重新添加
	标记有初始化bean前回调
	标记有销毁前回调bean
	添加集合末端
	 */
	public void addBeanPostProcessor(BeanPostProcessor beanPostProcessor) {
		Assert.notNull(beanPostProcessor, "BeanPostProcessor must not be null");
		// Remove from old position, if any
		//移除,避免重新添加
		this.beanPostProcessors.remove(beanPostProcessor);
		// Track whether it is instantiation/destruction aware
		//标记有初始化bean前回调
		if (beanPostProcessor instanceof InstantiationAwareBeanPostProcessor) {
			this.hasInstantiationAwareBeanPostProcessors = true;
		}
		//标记有销毁前回调bean
		if (beanPostProcessor instanceof DestructionAwareBeanPostProcessor) {
			this.hasDestructionAwareBeanPostProcessors = true;
		}
		// Add to end of list
		//添加集合末端
		this.beanPostProcessors.add(beanPostProcessor);
	}

初始化应用消息广播器

/*
	注册默认applicationEventMulticaster监听器
	 */
	protected void initApplicationEventMulticaster() {
		ConfigurableListableBeanFactory beanFactory = getBeanFactory();
		if (beanFactory.containsLocalBean(APPLICATION_EVENT_MULTICASTER_BEAN_NAME)) {
			this.applicationEventMulticaster =
					beanFactory.getBean(APPLICATION_EVENT_MULTICASTER_BEAN_NAME, ApplicationEventMulticaster.class);
			if (logger.isTraceEnabled()) {
				logger.trace("Using ApplicationEventMulticaster [" + this.applicationEventMulticaster + "]");
			}
		}
		else {
			this.applicationEventMulticaster = new SimpleApplicationEventMulticaster(beanFactory);
			beanFactory.registerSingleton(APPLICATION_EVENT_MULTICASTER_BEAN_NAME, this.applicationEventMulticaster);
			if (logger.isTraceEnabled()) {
				logger.trace("No '" + APPLICATION_EVENT_MULTICASTER_BEAN_NAME + "' bean, using " +
						"[" + this.applicationEventMulticaster.getClass().getSimpleName() + "]");
			}
		}
	}

/*
	注册硬编码和配置文件注册的监听器处理
	通知早期注入的事件
	 */
	protected void registerListeners() {
		// Register statically specified listeners first.
		//硬编码方式注册的监听器处理
		for (ApplicationListener<?> listener : getApplicationListeners()) {
			getApplicationEventMulticaster().addApplicationListener(listener);
		}

		// Do not initialize FactoryBeans here: We need to leave all regular beans
		// uninitialized to let post-processors apply to them!
		//配置文件注册的监听器处理
		String[] listenerBeanNames = getBeanNamesForType(ApplicationListener.class, true, false);
		for (String listenerBeanName : listenerBeanNames) {
			getApplicationEventMulticaster().addApplicationListenerBean(listenerBeanName);
		}

		// Publish early application events now that we finally have a multicaster...
		//通知早期注入的事件
		Set<ApplicationEvent> earlyEventsToProcess = this.earlyApplicationEvents;
		this.earlyApplicationEvents = null;
		if (earlyEventsToProcess != null) {
			for (ApplicationEvent earlyEvent : earlyEventsToProcess) {
				getApplicationEventMulticaster().multicastEvent(earlyEvent);
			}
		}
	}

初始化剩下的非延迟初始化单实例

	/*
	自定义转换器Conver
	注册默认的嵌入式值解析器
	初始化LTW
	停止使用临时加载器类型匹配
	冻结所有的bean定义
	初始化剩下的单实例(非懒加载)
	 */
	protected void finishBeanFactoryInitialization(ConfigurableListableBeanFactory beanFactory) {
		// Initialize conversion service for this context.
		//自定义转换器Conver,名字必须conversionService
		if (beanFactory.containsBean(CONVERSION_SERVICE_BEAN_NAME) &&
				beanFactory.isTypeMatch(CONVERSION_SERVICE_BEAN_NAME, ConversionService.class)) {
			beanFactory.setConversionService(
					beanFactory.getBean(CONVERSION_SERVICE_BEAN_NAME, ConversionService.class));
		}

		// Register a default embedded value resolver if no bean post-processor
		// (such as a PropertyPlaceholderConfigurer bean) registered any before:
		// at this point, primarily for resolution in annotation attribute values.
		// 如果在此之前没有任何bean后处理器（如propertyplaceholderconfigurerbean）注册，
		// 则注册默认的嵌入式值解析器：此时，主要是为了在注释属性值中进行解析。
		if (!beanFactory.hasEmbeddedValueResolver()) {//要应用的字符串解析器，例如用于注释属性值。
			beanFactory.addEmbeddedValueResolver(strVal -> getEnvironment().resolvePlaceholders(strVal));
		}

		// Initialize LoadTimeWeaverAware beans early to allow for registering their transformers early.
		//初始化LTW
		String[] weaverAwareNames = beanFactory.getBeanNamesForType(LoadTimeWeaverAware.class, false, false);
		for (String weaverAwareName : weaverAwareNames) {
			getBean(weaverAwareName);
		}

		// Stop using the temporary ClassLoader for type matching.
		//停止使用临时加载器类型匹配
		beanFactory.setTempClassLoader(null);

		// Allow for caching all bean definition metadata, not expecting further changes.
		//冻结所有的bean定义,说明注册的bean定义将不被修改或任何进一步的处理
		beanFactory.freezeConfiguration();

		// Instantiate all remaining (non-lazy-init) singletons.
		//初始化剩下的单实例(非懒加载)
		beanFactory.preInstantiateSingletons();
	}

/*
	加载所有非抽象,非懒加载,且单例的对象
		针对实现了SmartFactoryBean的工厂bean特别处理
	针对实现了SmartInitializingSingleton接口的执行初始化后方法
	 */
	@Override
	public void preInstantiateSingletons() throws BeansException {
		if (logger.isTraceEnabled()) {
			logger.trace("Pre-instantiating singletons in " + this);
		}

		// Iterate over a copy to allow for init methods which in turn register new bean definitions.
		// While this may not be part of the regular factory bootstrap, it does otherwise work fine.
		List<String> beanNames = new ArrayList<>(this.beanDefinitionNames);

		// Trigger initialization of all non-lazy singleton beans...
		for (String beanName : beanNames) {
			RootBeanDefinition bd = getMergedLocalBeanDefinition(beanName);
			//非抽象,非懒加载,且单例
			if (!bd.isAbstract() && bd.isSingleton() && !bd.isLazyInit()) {
				//是否工厂Bean
				if (isFactoryBean(beanName)) {
					Object bean = getBean(FACTORY_BEAN_PREFIX + beanName);
					if (bean instanceof FactoryBean) {
						final FactoryBean<?> factory = (FactoryBean<?>) bean;
						boolean isEagerInit;
						if (System.getSecurityManager() != null && factory instanceof SmartFactoryBean) {
							isEagerInit = AccessController.doPrivileged((PrivilegedAction<Boolean>)
											((SmartFactoryBean<?>) factory)::isEagerInit,
									getAccessControlContext());
						}
						else {
							//是否迫切初始化
							isEagerInit = (factory instanceof SmartFactoryBean &&
									((SmartFactoryBean<?>) factory).isEagerInit());
						}
						if (isEagerInit) {
							//初始化
							getBean(beanName);
						}
					}
				}
				else {
					getBean(beanName);
				}
			}
		}

		// Trigger post-initialization callback for all applicable beans...
		for (String beanName : beanNames) {
			Object singletonInstance = getSingleton(beanName);
			if (singletonInstance instanceof SmartInitializingSingleton) {
				//初始化后回调接口
				final SmartInitializingSingleton smartSingleton = (SmartInitializingSingleton) singletonInstance;
				if (System.getSecurityManager() != null) {
					AccessController.doPrivileged((PrivilegedAction<Object>) () -> {
						smartSingleton.afterSingletonsInstantiated();
						return null;
					}, getAccessControlContext());
				}
				else {
					smartSingleton.afterSingletonsInstantiated();
				}
			}
		}
	}

完成刷新

	/*
	清除资源缓存
	初始化LifecycleProcessor
	启动所有实现了Lifecycle的bean
	推送监听器.
	...
	 */
	protected void finishRefresh() {
		// Clear context-level resource caches (such as ASM metadata from scanning).
		//清除资源缓存
		clearResourceCaches();

		// Initialize lifecycle processor for this context.
		//初始化LifecycleProcessor
		//spring启动LifecycleProcessor的时候调用start,关闭的时候调用stop，通常用来配置后台程序，如MQ轮询
		initLifecycleProcessor();

		// Propagate refresh to lifecycle processor first.
		//启动所有实现了Lifecycle的bean
		getLifecycleProcessor().onRefresh();

		// Publish the final event.
		//推送监听器.
		publishEvent(new ContextRefreshedEvent(this));

		// Participate in LiveBeansView MBean, if active.
		//这个搞不懂
		LiveBeansView.registerApplicationContext(this);
	}

/*
		初始化lifecycleProcessor
	 */
	protected void initLifecycleProcessor() {
		ConfigurableListableBeanFactory beanFactory = getBeanFactory();
		//是否包含lifecycleProcessor
		if (beanFactory.containsLocalBean(LIFECYCLE_PROCESSOR_BEAN_NAME)) {
			this.lifecycleProcessor =
					beanFactory.getBean(LIFECYCLE_PROCESSOR_BEAN_NAME, LifecycleProcessor.class);
			if (logger.isTraceEnabled()) {
				logger.trace("Using LifecycleProcessor [" + this.lifecycleProcessor + "]");
			}
		}
		else {
			//初始化默认lifecycleProcessor
			DefaultLifecycleProcessor defaultProcessor = new DefaultLifecycleProcessor();
			defaultProcessor.setBeanFactory(beanFactory);
			this.lifecycleProcessor = defaultProcessor;
			beanFactory.registerSingleton(LIFECYCLE_PROCESSOR_BEAN_NAME, this.lifecycleProcessor);
			if (logger.isTraceEnabled()) {
				logger.trace("No '" + LIFECYCLE_PROCESSOR_BEAN_NAME + "' bean, using " +
						"[" + this.lifecycleProcessor.getClass().getSimpleName() + "]");
			}
		}
	}

/*
		装饰事件
		广播指定事件给指定监听器
		推送事件到parent context
	 */
	protected void publishEvent(Object event, @Nullable ResolvableType eventType) {
		Assert.notNull(event, "Event must not be null");

		// Decorate event as an ApplicationEvent if necessary
		//如有必要，将事件装饰为ApplicationEvent
		ApplicationEvent applicationEvent;
		if (event instanceof ApplicationEvent) {
			applicationEvent = (ApplicationEvent) event;
		}
		else {
			applicationEvent = new PayloadApplicationEvent<>(this, event);
			if (eventType == null) {
				eventType = ((PayloadApplicationEvent<?>) applicationEvent).getResolvableType();
			}
		}

		// Multicast right now if possible - or lazily once the multicaster is initialized
		//如果可能的话，现在就进行多播-或者在初始化多播主机后进行惰性的多播
		if (this.earlyApplicationEvents != null) {
			this.earlyApplicationEvents.add(applicationEvent);
		}
		else {
			//自定义的事件,广播到指定类型上
			getApplicationEventMulticaster().multicastEvent(applicationEvent, eventType);
		}

		// Publish event via parent context as well...
		//推送事件到parent context
		if (this.parent != null) {
			if (this.parent instanceof AbstractApplicationContext) {
				((AbstractApplicationContext) this.parent).publishEvent(event, eventType);
			}
			else {
				//通知所有注册的监听器
				this.parent.publishEvent(event);
			}
		}
	}