03.03 ConfigurationClassPostProcessor 解析配置类.

linweiwang · Apr 25, 2024 · 64b6977 · 64b6977
1 parent d8afaac
commit 64b6977
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diff --git a/...ontext/src/main/java/org/springframework/context/annotation/ConfigurationClassParser.java b/...ontext/src/main/java/org/springframework/context/annotation/ConfigurationClassParser.java
@@ -170,6 +170,7 @@ public void parse(Set<BeanDefinitionHolder> configCandidates) {
 		for (BeanDefinitionHolder holder : configCandidates) {
 			BeanDefinition bd = holder.getBeanDefinition();
 			try {
+				// 解析
 				if (bd instanceof AnnotatedBeanDefinition) {
 					parse(((AnnotatedBeanDefinition) bd).getMetadata(), holder.getBeanName());
 				}
@@ -246,6 +247,7 @@ protected void processConfigurationClass(ConfigurationClass configClass, Predica
 		// Recursively process the configuration class and its superclass hierarchy.
 		SourceClass sourceClass = asSourceClass(configClass, filter);
 		do {
+			// 真正去解析
 			sourceClass = doProcessConfigurationClass(configClass, sourceClass, filter);
 		}
 		while (sourceClass != null);
@@ -266,11 +268,13 @@ protected final SourceClass doProcessConfigurationClass(
 			ConfigurationClass configClass, SourceClass sourceClass, Predicate<String> filter)
 			throws IOException {
 
+		// 解析 @Component
 		if (configClass.getMetadata().isAnnotated(Component.class.getName())) {
 			// Recursively process any member (nested) classes first
 			processMemberClasses(configClass, sourceClass, filter);
 		}
 
+		// 解析 @PropertySource
 		// Process any @PropertySource annotations
 		for (AnnotationAttributes propertySource : AnnotationConfigUtils.attributesForRepeatable(
 				sourceClass.getMetadata(), PropertySources.class,
@@ -284,6 +288,7 @@ protected final SourceClass doProcessConfigurationClass(
 			}
 		}
 
+		// 解析 @ComponentScan
 		// Process any @ComponentScan annotations
 		Set<AnnotationAttributes> componentScans = AnnotationConfigUtils.attributesForRepeatable(
 				sourceClass.getMetadata(), ComponentScans.class, ComponentScan.class);
@@ -306,9 +311,11 @@ protected final SourceClass doProcessConfigurationClass(
 			}
 		}
 
+		// 解析 @Import
 		// Process any @Import annotations
 		processImports(configClass, sourceClass, getImports(sourceClass), filter, true);
 
+		// 解析 @ImportResource
 		// Process any @ImportResource annotations
 		AnnotationAttributes importResource =
 				AnnotationConfigUtils.attributesFor(sourceClass.getMetadata(), ImportResource.class);
@@ -321,6 +328,7 @@ protected final SourceClass doProcessConfigurationClass(
 			}
 		}
 
+		// 解析 @ImportResource
 		// Process individual @Bean methods
 		Set<MethodMetadata> beanMethods = retrieveBeanMethodMetadata(sourceClass);
 		for (MethodMetadata methodMetadata : beanMethods) {

diff --git a/...src/main/java/org/springframework/context/annotation/ConfigurationClassPostProcessor.java b/...src/main/java/org/springframework/context/annotation/ConfigurationClassPostProcessor.java
@@ -229,6 +229,7 @@ public void setApplicationStartup(ApplicationStartup applicationStartup) {
 	}
 
 	/**
+	 * 拿到所有配置类中的所有 Bean 定义信息
 	 * Derive further bean definitions from the configuration classes in the registry.
 	 */
 	@Override
@@ -244,6 +245,7 @@ public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) {
 		}
 		this.registriesPostProcessed.add(registryId);
 
+		// 进行后置增强处理
 		processConfigBeanDefinitions(registry);
 	}
 
@@ -277,6 +279,7 @@ public void processConfigBeanDefinitions(BeanDefinitionRegistry registry) {
 		List<BeanDefinitionHolder> configCandidates = new ArrayList<>();
 		String[] candidateNames = registry.getBeanDefinitionNames();
 
+		// 遍历所有的候选 BeanName
 		for (String beanName : candidateNames) {
 			BeanDefinition beanDef = registry.getBeanDefinition(beanName);
 			if (beanDef.getAttribute(ConfigurationClassUtils.CONFIGURATION_CLASS_ATTRIBUTE) != null) {
@@ -285,6 +288,7 @@ public void processConfigBeanDefinitions(BeanDefinitionRegistry registry) {
 				}
 			}
 			else if (ConfigurationClassUtils.checkConfigurationClassCandidate(beanDef, this.metadataReaderFactory)) {
+				// 将配置类加入候选集和中
 				configCandidates.add(new BeanDefinitionHolder(beanDef, beanName));
 			}
 		}
@@ -294,18 +298,22 @@ else if (ConfigurationClassUtils.checkConfigurationClassCandidate(beanDef, this.
 			return;
 		}
 
+		// 排序
 		// Sort by previously determined @Order value, if applicable
 		configCandidates.sort((bd1, bd2) -> {
 			int i1 = ConfigurationClassUtils.getOrder(bd1.getBeanDefinition());
 			int i2 = ConfigurationClassUtils.getOrder(bd2.getBeanDefinition());
 			return Integer.compare(i1, i2);
 		});
 
+		// 单实例的注册中心
 		// Detect any custom bean name generation strategy supplied through the enclosing application context
 		SingletonBeanRegistry sbr = null;
 		if (registry instanceof SingletonBeanRegistry) {
 			sbr = (SingletonBeanRegistry) registry;
 			if (!this.localBeanNameGeneratorSet) {
+				// 获取 CONFIGURATION_BEAN_NAME_GENERATOR 的组件
+				// "org.springframework.context.annotation.internalConfigurationBeanNameGenerator"
 				BeanNameGenerator generator = (BeanNameGenerator) sbr.getSingleton(
 						AnnotationConfigUtils.CONFIGURATION_BEAN_NAME_GENERATOR);
 				if (generator != null) {
@@ -319,6 +327,7 @@ else if (ConfigurationClassUtils.checkConfigurationClassCandidate(beanDef, this.
 			this.environment = new StandardEnvironment();
 		}
 
+		// 使用 ConfigurationClassParser 解析配置类，即 @Configuration 注解的类
 		// Parse each @Configuration class
 		ConfigurationClassParser parser = new ConfigurationClassParser(
 				this.metadataReaderFactory, this.problemReporter, this.environment,
@@ -328,6 +337,7 @@ else if (ConfigurationClassUtils.checkConfigurationClassCandidate(beanDef, this.
 		Set<ConfigurationClass> alreadyParsed = new HashSet<>(configCandidates.size());
 		do {
 			StartupStep processConfig = this.applicationStartup.start("spring.context.config-classes.parse");
+			// 解析配置类
 			parser.parse(candidates);
 			parser.validate();
 

diff --git a/.../src/main/java/org/springframework/context/support/PostProcessorRegistrationDelegate.java b/.../src/main/java/org/springframework/context/support/PostProcessorRegistrationDelegate.java
@@ -101,6 +101,8 @@ public static void invokeBeanFactoryPostProcessors(
 			List<BeanDefinitionRegistryPostProcessor> currentRegistryProcessors = new ArrayList<>();
 
 			// 首先：调用实现 PriorityOrdered 的BeanDefinitionRegistryPostProcessors
+			//         此处会获取底层 org.springframework.context.annotation.internalConfigurationAnnotationProcessor
+			//
 			// First, invoke the BeanDefinitionRegistryPostProcessors that implement PriorityOrdered.
 			String[] postProcessorNames =
 					beanFactory.getBeanNamesForType(BeanDefinitionRegistryPostProcessor.class, true, false);