SpringApplicationContext Over！！！

spring-framework-main/spring-beans/src/main/java/org/springframework/beans/factory/support/DefaultListableBeanFactory.java

@@ -912,12 +912,17 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 
 		// 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.
+		// 1.创建beanDefinitionNames的副本beanNames用于后续的遍历，以允许init等方法注册新的bean定义
 		List<String> beanNames = new ArrayList<>(this.beanDefinitionNames);
 
 		// Trigger initialization of all non-lazy singleton beans...
+		// 2.遍历beanNames，触发所有非懒加载单例bean的初始化
 		for (String beanName : beanNames) {
+			// 3.获取beanName对应的MergedBeanDefinition
 			RootBeanDefinition bd = getMergedLocalBeanDefinition(beanName);
+			// 4.bd对应的Bean实例：不是抽象类 && 是单例 && 不是懒加载
 			if (!bd.isAbstract() && bd.isSingleton() && !bd.isLazyInit()) {
+				// 5.判断 bean 是否为 FactoryBean
 				if (isFactoryBean(beanName)) {
 					Object bean = getBean(FACTORY_BEAN_PREFIX + beanName);
 					if (bean instanceof SmartFactoryBean<?> smartFactoryBean && smartFactoryBean.isEagerInit()) {
@@ -925,14 +930,18 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 					}
 				}
 				else {
+					// 6.如果beanName对应的bean不是 FactoryBean，只是普通Bean，通过beanName获取bean实例
 					getBean(beanName);
 				}
 			}
 		}
 
 		// Trigger post-initialization callback for all applicable beans...
+		// 7.遍历 beanNames，触发所有 SmartInitializingSingleton 的后初始化回调
 		for (String beanName : beanNames) {
+			// 7.1 拿到beanName对应的bean实例
 			Object singletonInstance = getSingleton(beanName);
+			// 7.2 判断 singletonInstance 是否实现了 SmartInitializingSingleton 接口
 			if (singletonInstance instanceof SmartInitializingSingleton smartSingleton) {
 				StartupStep smartInitialize = this.getApplicationStartup().start("spring.beans.smart-initialize")
 						.tag("beanName", beanName);

spring-framework-main/spring-context/src/main/java/org/springframework/context/support/AbstractApplicationContext.java

@@ -906,6 +906,7 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 	 */
 	protected void initLifecycleProcessor() {
 		ConfigurableListableBeanFactory beanFactory = getBeanFactory();
+		// 1.判断BeanFactory是否已经存在生命周期处理器（固定使用beanName=lifecycleProcessor）
 		if (beanFactory.containsLocalBean(LIFECYCLE_PROCESSOR_BEAN_NAME)) {
 			this.lifecycleProcessor =
 					beanFactory.getBean(LIFECYCLE_PROCESSOR_BEAN_NAME, LifecycleProcessor.class);
@@ -913,8 +914,10 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 				logger.trace("Using LifecycleProcessor [" + this.lifecycleProcessor + "]");
 			}
 		} else {
+			// 1.2 如果不存在，则使用DefaultLifecycleProcessor
 			DefaultLifecycleProcessor defaultProcessor = new DefaultLifecycleProcessor();
 			defaultProcessor.setBeanFactory(beanFactory);
+			// 并将 DefaultLifecycleProcessor 作为默认的生命周期处理器，注册到 BeanFactory 中
 			this.lifecycleProcessor = defaultProcessor;
 			beanFactory.registerSingleton(LIFECYCLE_PROCESSOR_BEAN_NAME, this.lifecycleProcessor);
 			if (logger.isTraceEnabled()) {
@@ -987,6 +990,7 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 		}
 
 		// Initialize LoadTimeWeaverAware beans early to allow for registering their transformers early.
+		// 3.初始化LoadTimeWeaverAware Bean实例对象
 		String[] weaverAwareNames = beanFactory.getBeanNamesForType(LoadTimeWeaverAware.class, false, false);
 		for (String weaverAwareName : weaverAwareNames) {
 			getBean(weaverAwareName);
@@ -996,9 +1000,11 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 		beanFactory.setTempClassLoader(null);
 
 		// Allow for caching all bean definition metadata, not expecting further changes.
+		// 4.冻结所有bean定义，注册的bean定义不会被修改或进一步后处理，因为马上要创建 Bean 实例对象了
 		beanFactory.freezeConfiguration();
 
 		// Instantiate all remaining (non-lazy-init) singletons.
+		// 5.实例化所有剩余（非懒加载）单例对象
 		beanFactory.preInstantiateSingletons();
 	}
 
@@ -1010,15 +1016,19 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 	@SuppressWarnings("deprecation")
 	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.
+		// 1.为此上下文初始化生命周期处理器
 		initLifecycleProcessor();
 
 		// Propagate refresh to lifecycle processor first.
+		// 2.首先将刷新完毕事件传播到生命周期处理器（触发isAutoStartup方法返回true的SmartLifecycle的start方法）
 		getLifecycleProcessor().onRefresh();
 
 		// Publish the final event.
+		// 3.推送上下文刷新完毕事件到相应的监听器
 		publishEvent(new ContextRefreshedEvent(this));
 	}
 

spring-framework-main/spring-context/src/main/java/org/springframework/context/support/DefaultLifecycleProcessor.java

@@ -139,9 +139,12 @@ public class DefaultLifecycleProcessor implements LifecycleProcessor, BeanFactor
 	// Internal helpers
 
 	private void startBeans(boolean autoStartupOnly) {
+		// 1.获取所有的Lifecycle bean
 		Map<String, Lifecycle> lifecycleBeans = getLifecycleBeans();
+		// 将Lifecycle bean 按阶段分组，阶段通过实现Phased接口得到
 		Map<Integer, LifecycleGroup> phases = new TreeMap<>();
 
+		// 2.遍历所有Lifecycle bean，按阶段值分组
 		lifecycleBeans.forEach((beanName, bean) -> {
 			if (!autoStartupOnly || (bean instanceof SmartLifecycle && ((SmartLifecycle) bean).isAutoStartup())) {
 				int phase = getPhase(bean);