目录
invokeBeanFactoryPostProcessors(beanFactory)
registerBeanPostProcessors(beanFactory)
initApplicationEventMulticaster()
invokeBeanFactoryPostProcessors(beanFactory)
调用在上下文中注册为bean的工厂处理器。（实例化并调用所有注册的BeanFactoryPostProcessor Bean，并遵循显式顺序（如果给定的话）。必须在单例实例化之前调用）
protected void invokeBeanFactoryPostProcessors(ConfigurableListableBeanFactory beanFactory) {
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)
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) {
// Invoke BeanDefinitionRegistryPostProcessors first, if any.
//如果有的话，首先调用BeanDefinitionRegistryPostProcessors。
Set<String> processedBeans = new HashSet<>();
if (beanFactory instanceof BeanDefinitionRegistry) {
BeanDefinitionRegistry registry = (BeanDefinitionRegistry) beanFactory;
// 用于存放普通的BeanFactoryPostProcessor
List<BeanFactoryPostProcessor> regularPostProcessors = new ArrayList<>();
// 用于存放BeanDefinitionRegistryPostProcessor
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);
}
}
// 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.
List<BeanDefinitionRegistryPostProcessor> currentRegistryProcessors = new ArrayList<>();
// First, invoke the BeanDefinitionRegistryPostProcessors that implement PriorityOrdered.
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();
// Next, invoke the BeanDefinitionRegistryPostProcessors that implement Ordered.
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.
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.
invokeBeanFactoryPostProcessors(registryProcessors, beanFactory);
invokeBeanFactoryPostProcessors(regularPostProcessors, beanFactory);
}
else {
// Invoke factory processors registered with the context instance.
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!
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<>();
for (String ppName : postProcessorNames) {
if (processedBeans.contains(ppName)) {
// skip - already processed in first phase above
}
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.
sortPostProcessors(priorityOrderedPostProcessors, beanFactory);
invokeBeanFactoryPostProcessors(priorityOrderedPostProcessors, beanFactory);
// Next, invoke the BeanFactoryPostProcessors that implement Ordered.
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.
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...
beanFactory.clearMetadataCache();
}- processedBeans 执行过的processor对应的bean名称。（上述方法会多次获取相同类型的processedBean,执行过的存到该集合中，防止多次执行）
- 如果有的话，首先调用BeanDefinitionRegistryPostProcessors。可以看出将目前的BeanFactoryPostProcessor分类存到不同的集合中。BeanDefinitionRegistryPostProcessor实例的执行对应的postProcessBeanDefinitionRegistry方法，存到registryProcessors（和bean定义注册相关的）。普通的直接存到regularPostProcessors中。
CachingMetadataReaderFactoryPostProcessor（ApplicationContextInitializer实现类SharedMetadataReaderFactoryContextInitializer调用initialize方法时添加的）属于BeanDefinitionRegistryPostProcessor。首先注册了一个class为SharedMetadataReaderFactoryBean的bean定义。然后配置了ConfigurationClassPostProcessor对应的bean定义，添加了一个metadataReaderFactory名称的属性，值为持有上述SharedMetadataReaderFactoryBean对应bean定义名称的引用RuntimeBeanReference（当引用工厂中的另一个bean时，用于属性值对象的不可变占位符类，将在运行时解析）
public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) throws BeansException {
register(registry);
configureConfigurationClassPostProcessor(registry);
}
private void register(BeanDefinitionRegistry registry) {
BeanDefinition definition = BeanDefinitionBuilder
.genericBeanDefinition(SharedMetadataReaderFactoryBean.class, SharedMetadataReaderFactoryBean::new)
.getBeanDefinition();
registry.registerBeanDefinition(BEAN_NAME, definition);
}
private void configureConfigurationClassPostProcessor(BeanDefinitionRegistry registry) {
try {
BeanDefinition definition = registry
.getBeanDefinition(AnnotationConfigUtils.CONFIGURATION_ANNOTATION_PROCESSOR_BEAN_NAME);
definition.getPropertyValues().add("metadataReaderFactory", new RuntimeBeanReference(BEAN_NAME));
}
catch (NoSuchBeanDefinitionException ex) {
}
}- 接着会处理实现了PriorityOrdered接口的所有BeanDefinitionRegistryPostProcessor。首先获取到BeanDefinitionRegistryPostProcessor类型的bean名称。在这里会获取到ConfigurationClassPostProcessor对应的bean名称"org.springframework.context.annotation.internalConfigurationAnnotationProcessor"，然后获取到ConfigurationClassPostProcessor示例，ConfigurationClassPostProcessor实现了PriorityOrdered接口，所以会添加到currentRegistryProcessors集合中（后续会执行的BeanDefinitionRegistryPostProcessor），排序号存放到上述registryProcessors中。接着会依次执行这些BeanDefinitionRegistryPostProcessor的postProcessBeanDefinitionRegistry方法。执行完清空currentRegistryProcessors。
- 同上再次获取Ordered接口的所有BeanDefinitionRegistryPostProcessor，然后重复上述步骤。
- 调用所有其他BeanDefinitionRegistryPostProcessor，直到没有其他的出现。所以这里会通过reiterate变量判断是否循环获取BeanDefinitionRegistryPostProcessor执行。直到没有可以执行的会设置为false.
同上再次所有BeanDefinitionRegistryPostProcessor，然后重复上述步骤。比如若项目中引入了mybatis,这里会获取到MapperScannerConfigurer这个BeanDefinitionRegistryPostProcessor，MapperScannerConfigurer没有实现Ordered接口，所以不会再上一步执行，而是会在这一步执行。 - 调用到目前为止已处理的所有处理器的postProcessBeanFactory回调(BeanFactoryPostProcessor的回调扩展接口)
- 最后，获取所有BeanFactoryPostProcessor，依次分为实现了PriorityOrdered接口的、实现了Ordered接口的和其它。然后依次按着三种类型执行postProcessBeanFactory回调。
- 结尾beanFactory.clearMetadataCache()：父类AbstractBeanFactory方法clearMetadataCache文档翻译：
清除合并的bean定义高速缓存，删除尚未被认为适合完全元数据高速缓存的bean条目。通常在更改原始bean定义之后触发，例如在应用BeanFactoryPostProcessor之后触发。 请注意，此时将保留已经创建的bean的元数据。
总结： 先执行已初始化的BeanDefinitionRegistryPostProcessor，然后按照依次实现了PriorityOrdered接口的、实现了Ordered接口的和其它的BeanDefinitionRegistryPostProcessor对应的bean定义且初始化并执行。接着调用这些BeanDefinitionRegistryPostProcessor父类BeanFactoryPostProcessor的扩展接口。 接着按照依次实现了PriorityOrdered接口的、实现了Ordered接口的和其它的BeanFactoryPostProcessor对应的bean定义且初始化并执行。
registerBeanPostProcessors(beanFactory)
注册拦截Bean创建的Bean处理器BeanPostProcessor（文档翻译：实例化并注册所有BeanPostProcessor Bean，并遵循显式顺序（如果有的话）。必须在应用程序bean的任何实例化之前调用。）
可总结如下：按照依次实现了PriorityOrdered接口的、实现了Ordered接口的和其它的BeanPostProcessor 对应的bean定义且初始化并添加到beanFactory中。然后将其中的属于MergedBeanDefinitionPostProcessor的实例重新注册
initMessageSource()
为此上下文初始化message source。注册了一个bean名称为messageSource的单例bean对象，值为DelegatingMessageSource
initApplicationEventMulticaster()
为上下文初始化事件多播器。注册了一个bean名称为applicationEventMulticaster的单例bean对象，值为SimpleApplicationEventMulticaster
onRefresh()
在特定上下文子类中初始化其他特殊bean。（下方方法在ServletWebServerApplicationContext中）
protected void onRefresh() {
super.onRefresh();
try {
createWebServer();
}
catch (Throwable ex) {
throw new ApplicationContextException("Unable to start web server", ex);
}
}由于使用的是默认的tomcat容器，所以下方ServletWebServerFactory 实例为TomcatServletWebServerFactory，获取到的webServer为TomcatWebServer
private void createWebServer() {
WebServer webServer = this.webServer;
ServletContext servletContext = getServletContext();
if (webServer == null && servletContext == null) {
ServletWebServerFactory factory = getWebServerFactory();
this.webServer = factory.getWebServer(getSelfInitializer());
}
else if (servletContext != null) {
try {
getSelfInitializer().onStartup(servletContext);
}
catch (ServletException ex) {
throw new ApplicationContextException("Cannot initialize servlet context", ex);
}
}
initPropertySources();
}