Spring教程之refresh()执行逻辑浅析

前言

对于AbstractApplicationContex#refresh()方法逻辑,可所谓是贯通spring框架核心逻辑,溪源在debug过程中,理解起来也是懵懵懂懂,自己也买了《Spring源码深度解析》书籍学习其思想和实现逻辑,经过不断的整理学习总结,最终诞生这篇文章,方便后面自己忘记了查看和理解。

下面开始正式踏入refresh方法的整体概览浅析。

概览

refresh

该方法是 Spring Bean 加载的核心,它是 ClassPathXmlApplicationContext 的父类 AbstractApplicationContext 的一个方法 , 顾名思义,用于刷新整个Spring 上下文信息,定义了整个 Spring 上下文加载的流程。

先看下refresh()方法总体:

@Override

public void refresh() throws BeansException, IllegalStateException {

synchronized (this.startupShutdownMonitor) {

// 准备预处理:记录容器的启动时间startupDate, 标记容器为激活,初始化上下文环境如文件路径信息,验证必填属性是否填写

this.prepareRefresh();

// **告诉子类去刷新bean工厂,此方法解析配置文件并将bean信息存储到beanDefinition中,注册到BeanFactory(但是未被初始化,仅将信息写到了beanDefination的map中)**重点方法,下面的操作都基于这个beanFactory进行的

ConfigurableListableBeanFactory beanFactory = this.obtainFreshBeanFactory();

// 设置beanFactory的基本属性:类加载器,添加多个beanPostProcesser

this.prepareBeanFactory(beanFactory);

try {

// 空实现:允许子类上下文中对beanFactory做后期处理

this.postProcessBeanFactory(beanFactory);

/**************************以上是BeanFactory的创建及预准备工作 ****************/

// 调用BeanFactoryPostProcessor各个实现类的方法

this.invokeBeanFactoryPostProcessors(beanFactory);

// 注册 BeanPostProcessor 的实现类,注意看和 BeanFactoryPostProcessor 的区别

// 此接口两个方法: postProcessBeforeInitialization 和 postProcessAfterInitialization

// 两个方法分别在 Bean 初始化之前和初始化之后得到执行。注意,到这里 Bean 还没初始化

this.registerBeanPostProcessors(beanFactory);

//初始化ApplicationContext的MessageSource组件(资源文件),如国际化文件,消息解析,绑定等

this.initMessageSource();

//初始化ApplicationContext事件广播器

this.initApplicationEventMulticaster();

// 初始化子类特殊bean(钩子方法)

this.onRefresh();

// 获取所有的事件监听器,并将监听器注册到事件广播器

this.registerListeners();

//** 初始化所有singleton bean;**重点方法

this.finishBeanFactoryInitialization(beanFactory);

// 广播事件:ApplicationContext初始化完成

this.finishRefresh();

} catch (BeansException ex) {

if (logger.isWarnEnabled()) {

logger.warn("Exception encountered during context initialization - " + "cancelling refresh attempt: " + ex);

}

// 销毁bean

this.destroyBeans();

// 重置 'active' 标志.

this.cancelRefresh(ex);

throw ex;

}

}

明细

本篇文章,不会仔细往下探讨源码实现逻辑,先总结refresh()方法具体逻辑:

1.prepareRefresh

准备预处理:记录spring容器的启动时间startupDate, 标记容器为激活,初始化上下文环境如文件路径信息,验证必填属性是否填写。

  • initPropertySources():初始化一些属性设置;子类自定义个性化的属性设置方法;
  • getEnvironment().validateRequiredProperties():检验属性的合法等;
  • earlyApplicationEvents= new LinkedHashSet():保存容器中的一些早期的事件;

//刷新前的预处理;

protected void prepareRefresh() {

this.startupDate = System.currentTimeMillis();

this.closed.set(false);

this.active.set(true);

if (logger.isInfoEnabled()) {

logger.info("Refreshing " + this);

}

// 初始化一些属性设置;子类自定义个性化的属性设置方法;

initPropertySources();

// 校验配置文件的属性,合法性

getEnvironment().validateRequiredProperties();

//保存容器中的一些事件

this.earlyApplicationEvents = new LinkedHashSet<ApplicationEvent>();

}

2.obtainFreshBeanFactory

获取BeanFactory,解析配置文件,生成beanDefinition;

protected ConfigurableListableBeanFactory obtainFreshBeanFactory() {

refreshBeanFactory(); //创建了一个this.beanFactory = new DefaultListableBeanFactory();设置了序列化的ID

//返回刚才创建的DefaultListableBeanFactory

ConfigurableListableBeanFactory beanFactory = getBeanFactory();

if (logger.isDebugEnabled()) {

logger.debug("Bean factory for " + getDisplayName() + ": " + beanFactory);

}

return beanFactory;

}

3.prepareBeanFactory

该方法主要负责对BeanFactory的预准备工作,配置beanFactory的基础属性,比如ClassLoader和一些PostProcessor等。

这个方法主要是给BeanFactory设置一些基本的属性,比如类加载器、表达式解析器、属性编辑器,注册几个单例、添加一些不用注入的接口、添加解析依赖项等。

  • 设置BeanFactory的类加载器、支持表达式解析器…
  • 添加部分BeanPostProcessor【ApplicationContextAwareProcessor】
  • 设置忽略的自动装配的接口EnvironmentAware、EmbeddedValueResolverAware、xxx;
  • 注册可以解析的自动装配;我们能直接在任何组件中自动注入:

    BeanFactory、ResourceLoader、ApplicationEventPublisher、ApplicationContext

  • 添加BeanPostProcessor【ApplicationListenerDetector】
  • 添加编译时的AspectJ;
  • 给BeanFactory中注册一些能用的组件;

    environment【ConfigurableEnvironment】、

    systemProperties【Map<String, Object>】、

    systemEnvironment【Map<String, Object>】

protected void prepareBeanFactory(ConfigurableListableBeanFactory beanFactory) {

// Tell the internal bean factory to use the context's class loader etc.

//设置类加载器

beanFactory.setBeanClassLoader(getClassLoader());

//设置bean表达式解析器,详解见下文

beanFactory.setBeanExpressionResolver(new StandardBeanExpressionResolver());

//资源编辑注册器

beanFactory.addPropertyEditorRegistrar(new ResourceEditorRegistrar(this, getEnvironment()));

//添加一个BeanPostProcessor:ApplicationContextAwareProcessor,用于向实现类ApplitionContextAware中,调用setApplicationContext方法,并将ApplicationContext作为参数。

beanFactory.addBeanPostProcessor(new ApplicationContextAwareProcessor(this));

//添加忽略自动装配的接口

beanFactory.ignoreDependencyInterface(EnvironmentAware.class);

beanFactory.ignoreDependencyInterface(EmbeddedValueResolverAware.class);

beanFactory.ignoreDependencyInterface(ResourceLoaderAware.class);

beanFactory.ignoreDependencyInterface(ApplicationEventPublisherAware.class);

beanFactory.ignoreDependencyInterface(MessageSourceAware.class);

beanFactory.ignoreDependencyInterface(ApplicationContextAware.class);

// 注册几个解析依赖项,意思是,当一个Bean需要注入对应的类时,使用下面注册的这些类

//比如,如果@Autowire 一个BeanFactory,那么这个BeanFactory实际就是在此处注册的一个对象

//这几项分别是:BeanFactory、ResourceLoader、ApplicationEventPublisher、ApplicationContext

beanFactory.registerResolvableDependency(BeanFactory.class, beanFactory);

beanFactory.registerResolvableDependency(ResourceLoader.class, this);

beanFactory.registerResolvableDependency(ApplicationEventPublisher.class, this);

beanFactory.registerResolvableDependency(ApplicationContext.class, this);

// Detect a LoadTimeWeaver and prepare for weaving, if found.

//检查是否由LoadTimeWeaver,如果有loadTimeWeaver的bean,就放入一个BeanPostProcessor:LoadTimeWeaverAwareProcessor

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()));

}

// 注册environment,注册成单例

if (!beanFactory.containsLocalBean(ENVIRONMENT_BEAN_NAME)) {

beanFactory.registerSingleton(ENVIRONMENT_BEAN_NAME, getEnvironment());

}

//注册systemProperties 成单例

if (!beanFactory.containsLocalBean(SYSTEM_PROPERTIES_BEAN_NAME)) {

beanFactory.registerSingleton(SYSTEM_PROPERTIES_BEAN_NAME, getEnvironment().getSystemProperties());

}

//注册 systemEnvironment 成单例

if (!beanFactory.containsLocalBean(SYSTEM_ENVIRONMENT_BEAN_NAME)) {

beanFactory.registerSingleton(SYSTEM_ENVIRONMENT_BEAN_NAME, getEnvironment().getSystemEnvironment());

}

}

4.postProcessBeanFactory

主要负责在BeanFactory准备工作完成之后,beanFactory的后置处理工作;

protected void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) {

}

5. invokeBeanFactoryPostProcessors

protected void invokeBeanFactoryPostProcessors(ConfigurableListableBeanFactory beanFactory) {

// Invoke BeanDefinitionRegistryPostProcessors first, if any.

//用于存放已处理过的Bean

Set<String> processedBeans = new HashSet<String>();

//如果IOC容器是一个BeanDefinitionRegistry,有了注册BeanDefinition的能力,就可以执行BeanDefinitionRegistryPostProcessor的postProcessBeanDefinitionRegistry方法

if (beanFactory instanceof BeanDefinitionRegistry) {

BeanDefinitionRegistry registry = (BeanDefinitionRegistry) beanFactory;

//regularPostProcessors用于存放普通的BeanFactoryPostProcessor

List<BeanFactoryPostProcessor>

regularPostProcessors = new LinkedList<BeanFactoryPostProcessor>();

//registryPostProcessors用于存放 BeanDefinitionRegistryPostProcessor

List<BeanDefinitionRegistryPostProcessor>

registryPostProcessors = new LinkedList<BeanDefinitionRegistryPostProcessor>();

//查询通过addBeanFactoryPostProcessor等方法设置进来的的BeanFactoryPostProcessor(不是注册到IOC容器的中)

for (BeanFactoryPostProcessor postProcessor : getBeanFactoryPostProcessors()) {

//如果是 BeanDefinitionRegistryPostProcessor ,

//就先执行它的postProcessBeanDefinitionRegistry,用于向IOC中注册一些BeanDefinition,

//然后添加到registryPostProcessors队列中

if (postProcessor instanceof BeanDefinitionRegistryPostProcessor) {

BeanDefinitionRegistryPostProcessor registryPostProcessor =

(BeanDefinitionRegistryPostProcessor) postProcessor;

registryPostProcessor.postProcessBeanDefinitionRegistry(registry);

registryPostProcessors.add(registryPostProcessor);

}

else {

//如果是普通的BeanFactoryPostProcessor,就添加到regularPostProcessors队列中

regularPostProcessors.add(postProcessor);

}

}

//获取IOC容器中注册的BeanDefinitionRegistryPostProcessor,

//放入到registryPostProcessorBeans中,

//并按照Order排序

Map<String, BeanDefinitionRegistryPostProcessor> beanMap =

beanFactory.getBeansOfType(BeanDefinitionRegistryPostProcessor.class, true, false);

List<BeanDefinitionRegistryPostProcessor> registryPostProcessorBeans =

new ArrayList<BeanDefinitionRegistryPostProcessor>(beanMap.values());

OrderComparator.sort(registryPostProcessorBeans);

//先调用registryPostProcessorBeans中的所有postProcessBeanDefinitionRegistry方法

for (BeanDefinitionRegistryPostProcessor postProcessor : registryPostProcessorBeans) {

postProcessor.postProcessBeanDefinitionRegistry(registry);

}

//先调用 registryPostProcessors中的postProcessBeanFactory方法

//再调用 registryPostProcessorBeans中的postProcessBeanFactory方法

//最后调用 regularPostProcessors中的postProcessBeanFactory方法

invokeBeanFactoryPostProcessors(registryPostProcessors, beanFactory);

invokeBeanFactoryPostProcessors(registryPostProcessorBeans, beanFactory);

invokeBeanFactoryPostProcessors(regularPostProcessors, beanFactory);

//对于IOC容器中注册的BeanDefinitionRegistryPostProcessor来说,还要放置到processedBeans中,放置重复调用

processedBeans.addAll(beanMap.keySet());

}

else {

//如果IOC就是一个普通的BeanFacotry,就直接从context中取出所有的BeanFactoryPostProcessor,并调用他们的postProcessBeanFactory方法

// Invoke factory processors registered with the context instance.

invokeBeanFactoryPostProcessors(getBeanFactoryPostProcessors(), beanFactory);

}

// Do not initialize FactoryBeans here: We need to leave all regular beans

// 查询IOC容器中所有的BeanFactoryPostProcessor,有可能上面的BeanDefinitionRegistryPostProcessor刚刚向IOC容器中注册了一些BeanFactoryPostProcessor,所以要在此处全部查出来。

String[] postProcessorNames =

beanFactory.getBeanNamesForType(BeanFactoryPostProcessor.class, true, false);

// 按照 这些BeanFactoryPostProcessor实现的排序接口( PriorityOrdered 和 Ordered)分成3组

//第一组 实现了PriorityOrdered --- priorityOrderedPostProcessors

//第二组 实现了Ordered --- orderedPostProcessorNames

//第三组 没有实现排序接口 --- nonOrderedPostProcessorNames

List<BeanFactoryPostProcessor> priorityOrderedPostProcessors = new ArrayList<BeanFactoryPostProcessor>();

List<String> orderedPostProcessorNames = new ArrayList<String>();

List<String> nonOrderedPostProcessorNames = new ArrayList<String>();

for (String ppName : postProcessorNames) {

//如果已经处理了,就跳过

if (processedBeans.contains(ppName)) {

// skip - already processed in first phase above

}

//实现PriorityOrdered 接口的

else if (isTypeMatch(ppName, PriorityOrdered.class)) {

priorityOrderedPostProcessors.add(beanFactory.getBean(ppName, BeanFactoryPostProcessor.class));

}

// 实现Ordered 接口的

else if (isTypeMatch(ppName, Ordered.class)) {

orderedPostProcessorNames.add(ppName);

}

//普通的

else {

nonOrderedPostProcessorNames.add(ppName);

}

}

//然后先执行priorityOrderedPostProcessors中的,再执行orderedPostProcessorNames的,最后执行nonOrderedPostProcessorNames

//排序并执行priorityOrderedPostProcessors的

OrderComparator.sort(priorityOrderedPostProcessors);

invokeBeanFactoryPostProcessors(priorityOrderedPostProcessors, beanFactory);

// 排序并执行orderedPostProcessors的

List<BeanFactoryPostProcessor> orderedPostProcessors = new ArrayList<BeanFactoryPostProcessor>();

for (String postProcessorName : orderedPostProcessorNames) {

orderedPostProcessors.add(getBean(postProcessorName, BeanFactoryPostProcessor.class));

}

OrderComparator.sort(orderedPostProcessors);

invokeBeanFactoryPostProcessors(orderedPostProcessors, beanFactory);

// 最后执行普通的BeanFactoryPostProcessor的

List<BeanFactoryPostProcessor> nonOrderedPostProcessors = new ArrayList<BeanFactoryPostProcessor>();

for (String postProcessorName : nonOrderedPostProcessorNames) {

nonOrderedPostProcessors.add(getBean(postProcessorName, BeanFactoryPostProcessor.class));

}

invokeBeanFactoryPostProcessors(nonOrderedPostProcessors, beanFactory);

}

6.registerBeanPostProcessors

protected void registerBeanPostProcessors(ConfigurableListableBeanFactory beanFactory) {

// 获取IOC中注册的 BeanPostProcessor

String[] postProcessorNames = beanFactory.getBeanNamesForType(BeanPostProcessor.class, true, false);

// BeanPostProcessorChecker 也是一个 BeanPostProcessor,用于检查一个Bean应该经过的BeanPostProcessor和

int beanProcessorTargetCount = beanFactory.getBeanPostProcessorCount() + 1 + postProcessorNames.length;

beanFactory.addBeanPostProcessor(new BeanPostProcessorChecker(beanFactory, beanProcessorTargetCount));

//按照排序接口分类。

//这里需要注意的是,priorityOrderedPostProcessors里面装的是BeanPostProcessor

//而orderedPostProcessorNames和nonOrderedPostProcessorNames里面装的是BeanPostProcessor的name

//原因是:实例化BeanPostProcessor实现类的时候,也需要调用IOC中已有的BeanPostProcessor,所以Spring这里没有提前实例化Orderd接口和普通的BeanPostProcessor。

//因此,这里有一个有趣的现象,示例化Orderd接口的BeanProcessor的时候,会使用PriorityOrdered的BeanPostProcessor进行处理

//实例化普通的BeanProcessor时,会先后经过PriorityOrdered和Orderd接口的BeanPostProcessor的处理

List<BeanPostProcessor> priorityOrderedPostProcessors = new ArrayList<BeanPostProcessor>();

List<BeanPostProcessor> internalPostProcessors = new ArrayList<BeanPostProcessor>();

List<String> orderedPostProcessorNames = new ArrayList<String>();

List<String> nonOrderedPostProcessorNames = new ArrayList<String>();

//分类

for (String ppName : postProcessorNames) {

//PriorityOrdered接口的,先行实例化,并把MergedBeanDefinitionPostProcessor放入到internalPostProcessors中

if (isTypeMatch(ppName, PriorityOrdered.class)) {

BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);

priorityOrderedPostProcessors.add(pp);

//

if (pp instanceof MergedBeanDefinitionPostProcessor) {

internalPostProcessors.add(pp);

}

}

//Ordered接口的,这里只是把name记录下来。

else if (isTypeMatch(ppName, Ordered.class)) {

//

orderedPostProcessorNames.add(ppName);

}

//普通的,这里只是把name记录下来。

else {

nonOrderedPostProcessorNames.add(ppName);

}

}

//排序并注册PriorityOrdered接口的BeanPostProcessor

OrderComparator.sort(priorityOrderedPostProcessors);

registerBeanPostProcessors(beanFactory, priorityOrderedPostProcessors);

//排序并注册Ordered接口的BeanPostProcessor

List<BeanPostProcessor> orderedPostProcessors = new ArrayList<BeanPostProcessor>();

for (String ppName : orderedPostProcessorNames) {

//这里才进行实例化,所以会使用实现了PriorityOrdered接口的BeanPostProcessor进行处理

BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);

orderedPostProcessors.add(pp);

//把MergedBeanDefinitionPostProcessor放入到internalPostProcessors中

if (pp instanceof MergedBeanDefinitionPostProcessor) {

internalPostProcessors.add(pp);

}

}

OrderComparator.sort(orderedPostProcessors);

registerBeanPostProcessors(beanFactory, orderedPostProcessors);

// 注册普通的BeanPostProcessor

List<BeanPostProcessor> nonOrderedPostProcessors = new ArrayList<BeanPostProcessor>();

for (String ppName : nonOrderedPostProcessorNames) {

//这里才进行实例化,所以会使用实现了PriorityOrdered接口或Orderd的BeanPostProcessor进行处理

BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);

nonOrderedPostProcessors.add(pp);

//把 MergedBeanDefinitionPostProcessor 放入到internalPostProcessors中

//同时注意到,即使在internalPostProcessors中

//BeanPostProcessor的顺序也是按照 PriorityOrderd > Orderd > 普通 的顺序进入的。

if (pp instanceof MergedBeanDefinitionPostProcessor) {

internalPostProcessors.add(pp);

}

}

registerBeanPostProcessors(beanFactory, nonOrderedPostProcessors);

//注册所有的MergedBeanDefinitionPostProcessor

OrderComparator.sort(internalPostProcessors);

registerBeanPostProcessors(beanFactory, internalPostProcessors);

//最后,在末尾添加一个ApplicationListenerDetector

beanFactory.addBeanPostProcessor(new ApplicationListenerDetector());

}

7.initMessageSource

初始化MessageSource组件(做国际化功能;消息绑定,消息解析);

  • 获取BeanFactory
  • 判断容器中是否有id为messageSource的,类型是MessageSource的组件;

    如果有赋值给messageSource,如果没有自己创建一个DelegatingMessageSource;

    MessageSource:取出国际化配置文件中的某个key的值;能按照区域信息获取;

  • 将创建完成的MessageSource注册在容器中,以后获取国际化配置文件的值的时候,可以自动注入MessageSource;

protected void initMessageSource() {

ConfigurableListableBeanFactory beanFactory = getBeanFactory();

if (beanFactory.containsLocalBean(MESSAGE_SOURCE_BEAN_NAME)) {

this.messageSource = beanFactory.getBean(MESSAGE_SOURCE_BEAN_NAME, MessageSource.class);

// Make MessageSource aware of parent MessageSource.

//如果已经注册了 messageSource && messageSource是HierarchicalMessageSource && messageSource没有parent && 此IOC有parent

if (this.parent != null && this.messageSource instanceof HierarchicalMessageSource) {

HierarchicalMessageSource hms = (HierarchicalMessageSource) this.messageSource;

if (hms.getParentMessageSource() == null) {

// Only set parent context as parent MessageSource if no parent MessageSource

// registered already.

hms.setParentMessageSource(getInternalParentMessageSource());

}

}

if (logger.isDebugEnabled()) {

logger.debug("Using MessageSource [" + this.messageSource + "]");

}

}

//如果没有注册messageSource,就创建一个DelegatingMessageSource,并注册到IOC中

else {

// Use empty MessageSource to be able to accept getMessage calls.

DelegatingMessageSource dms = new DelegatingMessageSource();

dms.setParentMessageSource(getInternalParentMessageSource());

this.messageSource = dms;

beanFactory.registerSingleton(MESSAGE_SOURCE_BEAN_NAME, this.messageSource);

if (logger.isDebugEnabled()) {

logger.debug("Unable to locate MessageSource with name '" + MESSAGE_SOURCE_BEAN_NAME +

"': using default [" + this.messageSource + "]");

}

}

}

8.initApplicationEventMulticaster

protected void initApplicationEventMulticaster() {

ConfigurableListableBeanFactory beanFactory = getBeanFactory();

//如果有开发自定的applicationEventMulticaster实例bean,则设置IOC的事件广播器为该实例

if (beanFactory.containsLocalBean(APPLICATION_EVENT_MULTICASTER_BEAN_NAME)) {

this.applicationEventMulticaster =

beanFactory.getBean(APPLICATION_EVENT_MULTICASTER_BEAN_NAME, ApplicationEventMulticaster.class);

if (logger.isDebugEnabled()) {

logger.debug("Using ApplicationEventMulticaster [" + this.applicationEventMulticaster + "]");

}

}

//如果没有applicationEventMulticaster,就设置一个SimpleApplicationEventMulticaster

else {

this.applicationEventMulticaster = new SimpleApplicationEventMulticaster(beanFactory);

beanFactory.registerSingleton(APPLICATION_EVENT_MULTICASTER_BEAN_NAME, this.applicationEventMulticaster);

if (logger.isDebugEnabled()) {

logger.debug("Unable to locate ApplicationEventMulticaster with name '" +

APPLICATION_EVENT_MULTICASTER_BEAN_NAME +

"': using default [" + this.applicationEventMulticaster + "]");

}

}

}

9.onRefresh

模板设计模式;该方法属于钩子方法;子类重写该方法并在容器刷新的时候自定义逻辑;

protected void onRefresh() throws BeansException {

// For subclasses: do nothing by default.

}

10.registerListeners

注册监听器分为两部分:

  1. 向事件分发器注册硬编码设置的applicationListener
  2. 向事件分发器注册一个IOC中的事件监听器(并不实例化)

protected void registerListeners() {

// 查出所有通过addApplicationListener方法添加的ApplicationListener,然后注册到事件广播器上

for (ApplicationListener<?> listener : getApplicationListeners()) {

getApplicationEventMulticaster().addApplicationListener(listener);

}

// 查出ioc容器中的所有ApplicationListener,只把他们注册到事件分发器的ApplicationListenerBean上,

// 待使用时再进行实例化

String[] listenerBeanNames = getBeanNamesForType(ApplicationListener.class, true, false);

for (String listenerBeanName : listenerBeanNames) {

getApplicationEventMulticaster().addApplicationListenerBean(listenerBeanName);

}

}

11.finishBeanFactoryInitialization

finishBeanFactoryInitialization主要是负责初始化单实例的bean;该方法是重点方法,bean的生命周期基本调用getBean()方法完成。

protected void finishBeanFactoryInitialization(ConfigurableListableBeanFactory beanFactory) {

//如果IOC中有conversionService的话,就实例化并设置到IOC中

//conversionService用于类型转换

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));

}

// 如果有LoadTimeWeaverAware,就实例化

String[] weaverAwareNames = beanFactory.getBeanNamesForType(LoadTimeWeaverAware.class, false, false);

for (String weaverAwareName : weaverAwareNames) {

getBean(weaverAwareName);

}

// 清理临时的classLoader

beanFactory.setTempClassLoader(null);

// 缓存所有beanDefinition的name,以备不时之需

beanFactory.freezeConfiguration();

// 实例化所有非non-lazy-init的单例

beanFactory.preInstantiateSingletons();

}

12.finishRefresh

完成bean创建和初始化过程,通知生命周期处理器 lifecycleProcessor 刷新过程,同时发出 ContextRefreshEvent 通知。

protected void finishRefresh() {

// 实例化或初始化lifecycleProcessor

initLifecycleProcessor();

// 调用lifecycleProcessor的刷新方法

getLifecycleProcessor().onRefresh();

//发布一个ContextRefreshedEvent事件

publishEvent(new ContextRefreshedEvent(this));

// 注册MBean,用于JMX管理

LiveBeansView.registerApplicationContext(this);

}

参考资料:

  • 解读Spring容器的refresh()
  • Spring 源码深度解析
  • Spring IoC之ApplicationContext中refresh过程

总结

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