在进行运行环境的判断情况下,就要开始加载相关的bean,属性文件的处理,属性值的处理等等操作。
进入refresh方法,可以看到当前这个方式是接口ConfigurableApplicationContext接口中的一个方法,这个方法有
当前这个类有28个实现类
我们直接看AbstractApplicationContext这个类,ApplicationContext接口的抽象实现。 不要求用于配置的存储类型; 简单地实现通用上下文功能。 使用模板方法设计模式,需要具体的子类来实现抽象方法。我们来看看这个类中的refresh方法:
public void refresh() throws BeansException, IllegalStateException {
synchronized (this.startupShutdownMonitor) {
//准备进行刷新context
prepareRefresh();
//告诉子类刷新内部bean factory
ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();
// 准备context中使用的bean factory
prepareBeanFactory(beanFactory);
try {
//允许在context子类中对bean factory进行后处理
postProcessBeanFactory(beanFactory);
//调用在context中注册为bean的工厂处理器
invokeBeanFactoryPostProcessors(beanFactory);
//注册拦截Bean创建的Bean处理器
registerBeanPostProcessors(beanFactory);
//为context初始化消息源
initMessageSource();
//为context初始化事件多播器
initApplicationEventMulticaster();
//在特定context子类中初始化其他特殊bean
onRefresh();
//检查侦听器bean并注册它们
registerListeners();
//实例化所有剩余的(非延迟初始化)单例
finishBeanFactoryInitialization(beanFactory);
//最后一步:发布相应的事件
finishRefresh();
}catch (BeansException ex) {
//销毁已创建的单例以避免资源悬空
destroyBeans();
//重置active标记.
cancelRefresh(ex);
//将异常传播给调用者
throw ex;
}finally {
//在Spring的核心中重置常见的自省缓存,因为我们可能再也不需要单例bean的元数据了
resetCommonCaches();
}
}
}
我们将一个方法一个方法的进行剖析refresh方法。
准备context以进行刷新,设置其启动日期和活动标志以及执行属性源的任何初始化。
protected void prepareRefresh() {
// 切换启动状态.
this.startupDate = System.currentTimeMillis();
this.closed.set(false);
this.active.set(true); //启动状态设置为true
//在context环境中初始化任何占位符属性源
//这个方法在AbstractApplicationContext相关的子类中进行实现
initPropertySources();
//验证所有标记为必需的属性都是可解析的
//ConfigurablePropertyResolver#setRequiredProperties
getEnvironment().validateRequiredProperties();
//存储预刷新的ApplicationListeners
if (this.earlyApplicationListeners == null) {
this.earlyApplicationListeners = new LinkedHashSet<>(this.applicationListeners);
}
else {
// 将本地应用程序侦听器重置为预刷新状态
this.applicationListeners.clear();
this.applicationListeners.addAll(this.earlyApplicationListeners);
}
//允许收集早期的ApplicationEvent,一旦多播器可用,便会发布
this.earlyApplicationEvents = new LinkedHashSet<>();
}
验证相关的属性:
通过PropertyResolver接口实现类加载先关的属性
这个方法的作用是告诉子类刷新内部的bean factory
refreshBeanFactory调用:
此实现对此context的基础bean工厂执行实际的刷新,关闭前一个bean工厂(如果有),并为上下文生命周期的下一阶段初始化一个新的bean工厂。
销毁此上下文管理的所有bean的模板方法。默认实现销毁此上下文中的所有缓存单例,调用DisposableBean.destroy()]和/或指定的“ destroy-method”。可以重写以添加context- 特定的bean销毁步骤在标准单例销毁之前或之后执行,而上下文的BeanFactory仍处于活动状态。
删除之后在进行创建bean,为此创建一个内部bean工厂
如果有实现ConfigurableApplicationContext,返回父context的内部beanFactory,否则返回父context
自定义内部beanFactory使用当前的context
通常通过以下方式将bean定义加载到给定的bean工厂中:
委托给一个或多个bean定义阅读器。
/**为register(Class ...)指定的任何类注册BeanDefinition并扫描所有包对于由setConfigLocation(String)或
setConfigLocations(String [])指定的任何值,请首先尝试将每个位置作为类加载,如果类加载成功并且类加载成功,
则注册BeanDefinition 失败(引发ClassNotFoundException),
假定该值是一个包,并尝试对其进行扫描以查找组件类。启用默认的批注配置后处理器集,例如可以使用@ Autowired,@ Required和关联的批注。
配置类Bean定义会使用生成的Bean定义名称进行注册,除非为原型注释提供了value属性。
**/
protected void loadBeanDefinitions(DefaultListableBeanFactory beanFactory) {
//通过AnnotatedBeanDefinitionReader注册BeanDefinition
AnnotatedBeanDefinitionReader reader = getAnnotatedBeanDefinitionReader(beanFactory);
//进行扫描classpath注册BeanDefinition
ClassPathBeanDefinitionScanner scanner = getClassPathBeanDefinitionScanner(beanFactory);
BeanNameGenerator beanNameGenerator = getBeanNameGenerator();
if (beanNameGenerator != null) {
reader.setBeanNameGenerator(beanNameGenerator);
scanner.setBeanNameGenerator(beanNameGenerator);
//注册单例bean
beanFactory.registerSingleton(AnnotationConfigUtils.CONFIGURATION_BEAN_NAME_GENERATOR, beanNameGenerator);
}
ScopeMetadataResolver scopeMetadataResolver = getScopeMetadataResolver();
if (scopeMetadataResolver != null) {
reader.setScopeMetadataResolver(scopeMetadataResolver);
scanner.setScopeMetadataResolver(scopeMetadataResolver);
}
if (!this.componentClasses.isEmpty()) {
if (logger.isDebugEnabled()) {
logger.debug("Registering component classes: [" + StringUtils.collectionToCommaDelimitedString(this.componentClasses) + "]");
}
//进行注册,注册一个或多个要处理的组件类
reader.register(ClassUtils.toClassArray(this.componentClasses));
}
if (!this.basePackages.isEmpty()) {
//进行扫描注册
scanner.scan(StringUtils.toStringArray(this.basePackages));
}
//获取相关的配置
String[] configLocations = getConfigLocations();
if (configLocations != null) {
for (String configLocation : configLocations) {
try {
Class<?> clazz = ClassUtils.forName(configLocation, getClassLoader());
if (logger.isTraceEnabled()) {
logger.trace("Registering [" + configLocation + "]");
}
reader.register(clazz);
}
catch (ClassNotFoundException ex) {
int count = scanner.scan(configLocation);
if (count == 0 && logger.isDebugEnabled()) {
logger.debug("No component classes found for specified class/package [" + configLocation + "]");
}
}
}
}
}
配置工厂的标准context特征,如上下文的ClassLoader和后处理器。
protected void prepareBeanFactory(ConfigurableListableBeanFactory beanFactory) {
// 告诉内部bean工厂使用context的类加载器等
beanFactory.setBeanClassLoader(getClassLoader());
beanFactory.setBeanExpressionResolver(new StandardBeanExpressionResolver(beanFactory.getBeanClassLoader()));
beanFactory.addPropertyEditorRegistrar(new ResourceEditorRegistrar(this, getEnvironment()));
//使用context回调配置Bean工厂
beanFactory.addBeanPostProcessor(new ApplicationContextAwareProcessor(this));
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接口未在普通工厂中注册为可解析类型
// essageSource注册为Bean(并发现用于自动装配)
beanFactory.registerResolvableDependency(BeanFactory.class, beanFactory);
beanFactory.registerResolvableDependency(ResourceLoader.class, this);
beanFactory.registerResolvableDependency(ApplicationEventPublisher.class, this);
beanFactory.registerResolvableDependency(ApplicationContext.class, this);
// 注册早期的后处理器以将内部bean检测为ApplicationListeners
beanFactory.addBeanPostProcessor(new ApplicationListenerDetector(this));
// 如果发现LoadTimeWeave
if (beanFactory.containsBean(LOAD_TIME_WEAVER_BEAN_NAME)) {
beanFactory.addBeanPostProcessor(new LoadTimeWeaverAwareProcessor(beanFactory));
// 设置一个临时的ClassLoader以进行类型匹配
beanFactory.setTempClassLoader(new ContextTypeMatchClassLoader(beanFactory.getBeanClassLoader()));
}
// 注册默认环境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());
}
}
注册request/session作用域(AbstractRefreshableWebApplicationContext.class):
注册ServletContextAwareProcessor(GenericWebApplicationContext.class):
/**
实例化并调用所有已注册的BeanFactoryPostProcessor Bean,
遵守明确的命令(如果有)
必须在单例实例化之前调用。
**/
protected void invokeBeanFactoryPostProcessors(ConfigurableListableBeanFactory beanFactory) {
PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(beanFactory, getBeanFactoryPostProcessors());
// 检测LoadTimeWeaver并准备编织(如果在此期间发现)
// 例如 通过ConfigurationClassPostProcessor注册的@Bean方法
if (beanFactory.getTempClassLoader() == null && beanFactory.containsBean(LOAD_TIME_WEAVER_BEAN_NAME)) {
beanFactory.addBeanPostProcessor(new LoadTimeWeaverAwareProcessor(beanFactory));
beanFactory.setTempClassLoader(new ContextTypeMatchClassLoader(beanFactory.getBeanClassLoader()));
}
}
public static void invokeBeanFactoryPostProcessors(
ConfigurableListableBeanFactory beanFactory, List<BeanFactoryPostProcessor> beanFactoryPostProcessors) {
// 如果有的话,首先调用BeanDefinitionRegistryPostProcessors
Set<String> processedBeans = new HashSet<>();
if (beanFactory instanceof BeanDefinitionRegistry) {
BeanDefinitionRegistry registry = (BeanDefinitionRegistry) beanFactory;
List<BeanFactoryPostProcessor> regularPostProcessors = new ArrayList<>();
List<BeanDefinitionRegistryPostProcessor> registryProcessors = new ArrayList<>();
for (BeanFactoryPostProcessor postProcessor : beanFactoryPostProcessors) {
if (postProcessor instanceof BeanDefinitionRegistryPostProcessor) {
BeanDefinitionRegistryPostProcessor registryProcessor =
(BeanDefinitionRegistryPostProcessor) postProcessor;
registryProcessor.postProcessBeanDefinitionRegistry(registry);
registryProcessors.add(registryProcessor);
}
else {
regularPostProcessors.add(postProcessor);
}
}
// 不要在这里初始化FactoryBeans:我们需要保留所有常规bean
// 未初始化,让Bean工厂后处理器对其应用
// 在实现的BeanDefinitionRegistryPostProcessor之间分开
// PriorityOrdered,Ordered和其他
List<BeanDefinitionRegistryPostProcessor> currentRegistryProcessors = new ArrayList<>();
//首先,调用实现PriorityOrdered的BeanDefinitionRegistryPostProcessors
String[] postProcessorNames =
beanFactory.getBeanNamesForType(BeanDefinitionRegistryPostProcessor.class, true, false);
for (String ppName : postProcessorNames) {
if (beanFactory.isTypeMatch(ppName, PriorityOrdered.class)) {
currentRegistryProcessors.add(beanFactory.getBean(ppName, BeanDefinitionRegistryPostProcessor.class));
processedBeans.add(ppName);
}
}
sortPostProcessors(currentRegistryProcessors, beanFactory);
registryProcessors.addAll(currentRegistryProcessors);
invokeBeanDefinitionRegistryPostProcessors(currentRegistryProcessors, registry);
currentRegistryProcessors.clear();
// 接下来,调用实现Ordered的BeanDefinitionRegistryPostProcessors
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();
// 最后,调用所有其他BeanDefinitionRegistryPostProcessor,直到没有其他的出现
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();
}
// 现在,调用到目前为止已处理的所有处理器的postProcessBeanFactory回调
invokeBeanFactoryPostProcessors(registryProcessors, beanFactory);
invokeBeanFactoryPostProcessors(regularPostProcessors, beanFactory);
}
else {
// 调用在上下文实例中注册的工厂处理器
invokeBeanFactoryPostProcessors(beanFactoryPostProcessors, beanFactory);
}
// 不要在这里初始化FactoryBeans:我们需要保留所有常规bean
// 未初始化,以让bean工厂后处理程序应用于它们
String[] postProcessorNames =
beanFactory.getBeanNamesForType(BeanFactoryPostProcessor.class, true, false);
// 在实现PriorityOrdered的BeanFactoryPostProcessor之间分开,
// Ordered, and the rest.
List<BeanFactoryPostProcessor> priorityOrderedPostProcessors = new ArrayList<>();
List<String> orderedPostProcessorNames = new ArrayList<>();
List<String> nonOrderedPostProcessorNames = new ArrayList<>();
for (String ppName : postProcessorNames) {
if (processedBeans.contains(ppName)) {
// 跳过-已在上面的第一阶段处理过
}
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);
}
}
// 首先,调用实现PriorityOrdered的BeanFactoryPostProcessors。
sortPostProcessors(priorityOrderedPostProcessors, beanFactory);
invokeBeanFactoryPostProcessors(priorityOrderedPostProcessors, beanFactory);
// 接下来,调用实现Ordered的BeanFactoryPostProcessors。
List<BeanFactoryPostProcessor> orderedPostProcessors = new ArrayList<>(orderedPostProcessorNames.size());
for (String postProcessorName : orderedPostProcessorNames) {
orderedPostProcessors.add(beanFactory.getBean(postProcessorName, BeanFactoryPostProcessor.class));
}
sortPostProcessors(orderedPostProcessors, beanFactory);
invokeBeanFactoryPostProcessors(orderedPostProcessors, beanFactory);
// 最后,调用所有其他beanfactorypostprocessor.
List<BeanFactoryPostProcessor> nonOrderedPostProcessors = new ArrayList<>(nonOrderedPostProcessorNames.size());
for (String postProcessorName : nonOrderedPostProcessorNames) {
nonOrderedPostProcessors.add(beanFactory.getBean(postProcessorName, BeanFactoryPostProcessor.class));
}
invokeBeanFactoryPostProcessors(nonOrderedPostProcessors, beanFactory);
// 清除缓存的合并bean定义,因为后处理器可能已经修改了原始元数据,例如 替换值中的占位符...
beanFactory.clearMetadataCache();
}
实例化并注册所有BeanPostProcessor bean,遵守明确的命令(如果有)必须在应用程序bean的任何实例化之前调用。
public static void registerBeanPostProcessors(
ConfigurableListableBeanFactory beanFactory, AbstractApplicationContext applicationContext) {
String[] postProcessorNames = beanFactory.getBeanNamesForType(BeanPostProcessor.class, true, false);
// 注册BeanPostProcessorChecker,当在BeanPostProcessor实例化期间创建Bean时,即当某个Bean不适合所有BeanPostProcessor处理时,记录一条信息消息
int beanProcessorTargetCount = beanFactory.getBeanPostProcessorCount() + 1 + postProcessorNames.length;
beanFactory.addBeanPostProcessor(new BeanPostProcessorChecker(beanFactory, beanProcessorTargetCount));
// 在实现PriorityOrdered的BeanPostProcessor之间分开
// Ordered, and the rest.
List<BeanPostProcessor> priorityOrderedPostProcessors = new ArrayList<>();
List<BeanPostProcessor> internalPostProcessors = new ArrayList<>();
List<String> orderedPostProcessorNames = new ArrayList<>();
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) {
internalPostProcessors.add(pp);
}
}
else if (beanFactory.isTypeMatch(ppName, Ordered.class)) {
orderedPostProcessorNames.add(ppName);
}
else {
nonOrderedPostProcessorNames.add(ppName);
}
}
// 首先,注册实现PriorityOrdered的BeanPostProcessor
sortPostProcessors(priorityOrderedPostProcessors, beanFactory);
registerBeanPostProcessors(beanFactory, priorityOrderedPostProcessors);
// 接下来,注册实现Ordered的BeanPostProcessor。
List<BeanPostProcessor> orderedPostProcessors = new ArrayList<>(orderedPostProcessorNames.size());
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);
// 现在,注册所有常规BeanPostProcessor
List<BeanPostProcessor> nonOrderedPostProcessors = new ArrayList<>(nonOrderedPostProcessorNames.size());
for (String ppName : nonOrderedPostProcessorNames) {
BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
nonOrderedPostProcessors.add(pp);
if (pp instanceof MergedBeanDefinitionPostProcessor) {
internalPostProcessors.add(pp);
}
}
registerBeanPostProcessors(beanFactory, nonOrderedPostProcessors);
// 最后,重新注册所有内部BeanPostProcessor
sortPostProcessors(internalPostProcessors, beanFactory);
registerBeanPostProcessors(beanFactory, internalPostProcessors);
// 重新注册后处理器以将内部bean检测为ApplicationListener,将其移至处理器链的末尾(用于拾取代理等)
beanFactory.addBeanPostProcessor(new ApplicationListenerDetector(applicationContext));
}
private static void sortPostProcessors(List<?> postProcessors, ConfigurableListableBeanFactory beanFactory) {
// Nothing to sort?
if (postProcessors.size() <= 1) {
return;
}
Comparator<Object> comparatorToUse = null;
if (beanFactory instanceof DefaultListableBeanFactory) {
comparatorToUse = ((DefaultListableBeanFactory) beanFactory).getDependencyComparator();
}
if (comparatorToUse == null) {
comparatorToUse = OrderComparator.INSTANCE;
}
postProcessors.sort(comparatorToUse);
}
以上两个方法将在后面讲解。
//初始化MessageSource,如果在此context中未定义,则使用父级的
protected void initMessageSource() {
//得到beanFactory
ConfigurableListableBeanFactory beanFactory = getBeanFactory();
//判断本地是否含有“messageSource”的bean
if (beanFactory.containsLocalBean(MESSAGE_SOURCE_BEAN_NAME)) {
this.messageSource = beanFactory.getBean(MESSAGE_SOURCE_BEAN_NAME, MessageSource.class);
// 使MessageSource知道父MessageSource
if (this.parent != null && this.messageSource instanceof HierarchicalMessageSource) {
HierarchicalMessageSource hms = (HierarchicalMessageSource) this.messageSource;
if (hms.getParentMessageSource() == null) {
// 如果没有父MessageSource,则仅将父上下文设置为父MessageSource已经注册
hms.setParentMessageSource(getInternalParentMessageSource());
}
}
}
else {
// 使用空的MessageSource可以接受getMessage调用。
DelegatingMessageSource dms = new DelegatingMessageSource();
dms.setParentMessageSource(getInternalParentMessageSource());
this.messageSource = dms;
beanFactory.registerSingleton(MESSAGE_SOURCE_BEAN_NAME, this.messageSource);
}
}
//初始化ApplicationEventMulticaster,如果在context中没有定义,则使用SimpleApplicationEventMulticaster
protected void initApplicationEventMulticaster() {
ConfigurableListableBeanFactory beanFactory = getBeanFactory();
//获得applicationEventMulticaster的bean
if (beanFactory.containsLocalBean(APPLICATION_EVENT_MULTICASTER_BEAN_NAME)) {
this.applicationEventMulticaster =
beanFactory.getBean(APPLICATION_EVENT_MULTICASTER_BEAN_NAME, ApplicationEventMulticaster.class);
}
else {
this.applicationEventMulticaster = new SimpleApplicationEventMulticaster(beanFactory);
beanFactory.registerSingleton(APPLICATION_EVENT_MULTICASTER_BEAN_NAME, this.applicationEventMulticaster);
}
}
首先注册静态指定的侦听器
不要在这里初始化FactoryBeans:我们需要保留所有未初始化的常规bean,以便后处理器对其应用!
多播器
protected void finishBeanFactoryInitialization(ConfigurableListableBeanFactory beanFactory) {
// 为此context初始化转换服务
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));
}
// 如果没有bean后处理器,则注册默认的嵌入式值解析器
// (例如PropertyPlaceholderConfigurer bean)之前注册过的任何东西:这主要是为了解析注释属性值
if (!beanFactory.hasEmbeddedValueResolver()) {
beanFactory.addEmbeddedValueResolver(strVal -> getEnvironment().resolvePlaceholders(strVal));
}
// 尽早初始化LoadTimeWeaverAware Bean,以便尽早注册其转换器
String[] weaverAwareNames = beanFactory.getBeanNamesForType(LoadTimeWeaverAware.class, false, false);
for (String weaverAwareName : weaverAwareNames) {
getBean(weaverAwareName);
}
// 停止使用临时ClassLoader进行类型匹配
beanFactory.setTempClassLoader(null);
// 允许缓存所有bean定义元数据,而不期望进一步的更改
beanFactory.freezeConfiguration();
// 实例化所有剩余的(非延迟初始化)单例
beanFactory.preInstantiateSingletons();
}
//完成此上下文的刷新,调用LifecycleProcessor的onRefresh()方法并发布ContextRefreshedEvent
protected void finishRefresh() {
// 清除上下文级别的资源缓存(如扫描的ASM元数据)
clearResourceCaches();
// 为此上下文初始化生命周期处理器
initLifecycleProcessor();
// 首先将刷新传播到生命周期处理器
getLifecycleProcessor().onRefresh();
// 发布最终事件
publishEvent(new ContextRefreshedEvent(this));
// Participate in LiveBeansView MBean, if active.
LiveBeansView.registerApplicationContext(this);
}
到这里应该就是刷新基本上就结束了,我们进行梳理一下:
在启动spring的时候,会对当前的context进行相关操作,如果找不到当前的context就会去寻找parent context,进行相关的操作。
applicationContext.refresh的操作流程如下:
如果出现异常,将会销毁bean,同时重置active标记,最后会在Spring的核心中重置常见的自省缓存,因为我们可能再也不需要单例bean的元数据了。