Spring上下文

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

@@ -175,7 +175,7 @@ final class PostProcessorRegistrationDelegate {
 
 			// Now, invoke the postProcessBeanFactory callback of all processors handled so far.
 			// 6.调用所有 BeanDefinitionRegistryPostProcessor 的 postProcessBeanFactory 方法
-			// (BeanDefinitionRegistryPostProcessor继承自BeanFactoryPostProcessor)
+			// (BeanDefinitionRegistryPostProcessor 继承自 BeanFactoryPostProcessor)
 			invokeBeanFactoryPostProcessors(registryProcessors, beanFactory);
 			// 7.最后, 调用入参 beanFactoryPostProcessors 中的普通 BeanFactoryPostProcessor 的 postProcessBeanFactory 方法
 			invokeBeanFactoryPostProcessors(regularPostProcessors, beanFactory);
@@ -263,20 +263,27 @@ final class PostProcessorRegistrationDelegate {
 		// to ensure that your proposal does not result in a breaking change:
 		// https://github.com/spring-projects/spring-framework/issues?q=PostProcessorRegistrationDelegate+is%3Aclosed+label%3A%22status%3A+declined%22
 
+		// 1.找出所有实现BeanPostProcessor接口的类
 		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.
+		// BeanPostProcessorChecker 是一个普通的信息打印，可能会有些情况，
+		// 当Spring中的后置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 中的信息
+		// BeanPostProcessor的目标计数
 		int beanProcessorTargetCount = beanFactory.getBeanPostProcessorCount() + 1 + postProcessorNames.length;
+		// 2.添加BeanPostProcessorChecker(主要用于记录信息)到beanFactory中
 		beanFactory.addBeanPostProcessor(new BeanPostProcessorChecker(beanFactory, beanProcessorTargetCount));
 
-		// Separate between BeanPostProcessors that implement PriorityOrdered,
-		// Ordered, and the rest.
+		// 3.定义不同的变量用于区分:
+		// 实现PriorityOrdered接口的BeanPostProcessor、实现Ordered接口的BeanPostProcessor、普通BeanPostProcessor
+		// 第一个是对象链表，第二三个是 beanName链表
+		// 用于存放实现PriorityOrdered接口的BeanPostProcessor
 		List<BeanPostProcessor> priorityOrderedPostProcessors = new ArrayList<>();
+		// 用于存放Spring内部的BeanPostProcessor
 		List<BeanPostProcessor> internalPostProcessors = new ArrayList<>();
 		List<String> orderedPostProcessorNames = new ArrayList<>();
 		List<String> nonOrderedPostProcessorNames = new ArrayList<>();
+		// 4.遍历 postProcessorNames, 将 BeanPostProcessors分开
 		for (String ppName : postProcessorNames) {
 			if (beanFactory.isTypeMatch(ppName, PriorityOrdered.class)) {
 				BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
@@ -321,11 +328,13 @@ final class PostProcessorRegistrationDelegate {
 		registerBeanPostProcessors(beanFactory, nonOrderedPostProcessors);
 
 		// Finally, re-register all internal BeanPostProcessors.
+		// 重新注册内部PostProcessors，（相当于内部的BeanPostProcessor会被移到处理器链的末尾）
 		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).
+		// 重新注册 ApplicationListenerDetector（跟上面类似，主要是为了移动到处理器链的末尾）
 		beanFactory.addBeanPostProcessor(new ApplicationListenerDetector(applicationContext));
 	}