吃透AOP

.idea/kotlinc.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="KotlinJpsPluginSettings">
+    <option name="version" value="1.6.20" />
+  </component>
+</project>
\ No newline at end of file

.idea/misc.xml

@@ -5,9 +5,4 @@
     <file type="web" url="file://$PROJECT_DIR$/spring-framework-main" />
     <file type="web" url="file://$PROJECT_DIR$/spring-framework-main" />
   </component>
   </component>
   <component name="ProjectRootManager" version="2" project-jdk-name="17" project-jdk-type="JavaSDK" />
   <component name="ProjectRootManager" version="2" project-jdk-name="17" project-jdk-type="JavaSDK" />
-  <component name="SwUserDefinedSpecifications">
-    <option name="specTypeByUrl">
-      <map />
-    </option>
-  </component>
 </project>
 </project>
\ No newline at end of file

spring-framework-main/spring-aop/src/main/java/org/springframework/aop/aspectj/annotation/AnnotationAwareAspectJAutoProxyCreator.java

@@ -89,9 +89,11 @@ public class AnnotationAwareAspectJAutoProxyCreator extends AspectJAwareAdvisorA
 	@Override
 	@Override
 	protected List<Advisor> findCandidateAdvisors() {
 	protected List<Advisor> findCandidateAdvisors() {
 		// Add all the Spring advisors found according to superclass rules.
 		// Add all the Spring advisors found according to superclass rules.
+		// 直接获取 容器中的 Advisor 类型的Bean
 		List<Advisor> advisors = super.findCandidateAdvisors();
 		List<Advisor> advisors = super.findCandidateAdvisors();
 		// Build Advisors for all AspectJ aspects in the bean factory.
 		// Build Advisors for all AspectJ aspects in the bean factory.
 		if (this.aspectJAdvisorsBuilder != null) {
 		if (this.aspectJAdvisorsBuilder != null) {
+			// 主要获取我们通过注解方式动态注册的 Advisors，比如根据不同表达式获取到的不同切点
 			advisors.addAll(this.aspectJAdvisorsBuilder.buildAspectJAdvisors());
 			advisors.addAll(this.aspectJAdvisorsBuilder.buildAspectJAdvisors());
 		}
 		}
 		return advisors;
 		return advisors;

spring-framework-main/spring-aop/src/main/java/org/springframework/aop/aspectj/annotation/BeanFactoryAspectJAdvisorsBuilder.java

@@ -84,13 +84,13 @@ public class BeanFactoryAspectJAdvisorsBuilder {
 		List<String> aspectNames = this.aspectBeanNames;
 		List<String> aspectNames = this.aspectBeanNames;
 
 
 		if (aspectNames == null) {
 		if (aspectNames == null) {
-			// 如果为空表示尚未缓存，进行缓存解析。这里用了DLC 方式来进行判断
+			// 如果为空表示尚未缓存，进行缓存解析。这里用了 DLC 方式来进行判断
 			synchronized (this) {
 			synchronized (this) {
 				aspectNames = this.aspectBeanNames;
 				aspectNames = this.aspectBeanNames;
 				if (aspectNames == null) {
 				if (aspectNames == null) {
 					List<Advisor> advisors = new ArrayList<>();
 					List<Advisor> advisors = new ArrayList<>();
 					aspectNames = new ArrayList<>();
 					aspectNames = new ArrayList<>();
-					// 1. 获取所有的beanName。从容器中获取所有的BeanName
+					// 1. 获取所有的 beanName。从容器中获取所有的BeanName
 					String[] beanNames = BeanFactoryUtils.beanNamesForTypeIncludingAncestors(
 					String[] beanNames = BeanFactoryUtils.beanNamesForTypeIncludingAncestors(
 							this.beanFactory, Object.class, true, false);
 							this.beanFactory, Object.class, true, false);
 					// 遍历beanName, 找出对应的增强方法
 					// 遍历beanName, 找出对应的增强方法
@@ -105,7 +105,7 @@ public class BeanFactoryAspectJAdvisorsBuilder {
 						if (beanType == null) {
 						if (beanType == null) {
 							continue;
 							continue;
 						}
 						}
-						// 2. 如果bean 被 @AspectJ 注解修饰 且不是 Ajc 编译, 则进一步处理
+						// 2. 如果 bean 被 @AspectJ 注解修饰 且不是 Ajc 编译, 则进一步处理
 						if (this.advisorFactory.isAspect(beanType)) {
 						if (this.advisorFactory.isAspect(beanType)) {
 							// 添加到缓存中
 							// 添加到缓存中
 							aspectNames.add(beanName);
 							aspectNames.add(beanName);
@@ -114,9 +114,11 @@ public class BeanFactoryAspectJAdvisorsBuilder {
 							if (amd.getAjType().getPerClause().getKind() == PerClauseKind.SINGLETON) {
 							if (amd.getAjType().getPerClause().getKind() == PerClauseKind.SINGLETON) {
 								MetadataAwareAspectInstanceFactory factory =
 								MetadataAwareAspectInstanceFactory factory =
 										new BeanFactoryAspectInstanceFactory(this.beanFactory, beanName);
 										new BeanFactoryAspectInstanceFactory(this.beanFactory, beanName);
-								// 3. 解析标记AspectJ注解中的增强方法，也就是被 @Before、@Around 等注解修饰的方法，并将其封装成 Advisor
+								// 3. 解析标记 AspectJ 注解中的增强方法，也就是被 @Before、@Around 等注解修饰的方法，并将其封装成 Advisor
+								// 每个方法解析成一个 Advisors
 								List<Advisor> classAdvisors = this.advisorFactory.getAdvisors(factory);
 								List<Advisor> classAdvisors = this.advisorFactory.getAdvisors(factory);
 								if (this.beanFactory.isSingleton(beanName)) {
 								if (this.beanFactory.isSingleton(beanName)) {
+									// 完成后加入缓存（单例）
 									this.advisorsCache.put(beanName, classAdvisors);
 									this.advisorsCache.put(beanName, classAdvisors);
 								}
 								}
 								else {
 								else {
@@ -151,6 +153,7 @@ public class BeanFactoryAspectJAdvisorsBuilder {
 		// 4. 将所有的增强方法保存到缓存中。
 		// 4. 将所有的增强方法保存到缓存中。
 		List<Advisor> advisors = new ArrayList<>();
 		List<Advisor> advisors = new ArrayList<>();
 		for (String aspectName : aspectNames) {
 		for (String aspectName : aspectNames) {
+			// 一个类可能有多个 Advisor
 			List<Advisor> cachedAdvisors = this.advisorsCache.get(aspectName);
 			List<Advisor> cachedAdvisors = this.advisorsCache.get(aspectName);
 			if (cachedAdvisors != null) {
 			if (cachedAdvisors != null) {
 				advisors.addAll(cachedAdvisors);
 				advisors.addAll(cachedAdvisors);

spring-framework-main/spring-aop/src/main/java/org/springframework/aop/aspectj/annotation/ReflectiveAspectJAdvisorFactory.java

@@ -146,7 +146,7 @@ public class ReflectiveAspectJAdvisorFactory extends AbstractAspectJAdvisorFacto
 			// discovered via reflection in order to support reliable advice ordering across JVM launches.
 			// discovered via reflection in order to support reliable advice ordering across JVM launches.
 			// Specifically, a value of 0 aligns with the default value used in
 			// Specifically, a value of 0 aligns with the default value used in
 			// AspectJPrecedenceComparator.getAspectDeclarationOrder(Advisor).
 			// AspectJPrecedenceComparator.getAspectDeclarationOrder(Advisor).
-			// 将方法封装成 Advisor 。如果找不到@PointCut 的信息，则会返回 null。
+			// 将方法封装成 Advisor 。如果找不到 @PointCut 的信息，则会返回 null。
 			Advisor advisor = getAdvisor(method, lazySingletonAspectInstanceFactory, 0, aspectName);
 			Advisor advisor = getAdvisor(method, lazySingletonAspectInstanceFactory, 0, aspectName);
 			if (advisor != null) {
 			if (advisor != null) {
 				advisors.add(advisor);
 				advisors.add(advisor);

spring-framework-main/spring-aop/src/main/java/org/springframework/aop/aspectj/autoproxy/AspectJAwareAdvisorAutoProxyCreator.java

@@ -98,13 +98,19 @@ public class AspectJAwareAdvisorAutoProxyCreator extends AbstractAdvisorAutoProx
 	@Override
 	@Override
 	protected boolean shouldSkip(Class<?> beanClass, String beanName) {
 	protected boolean shouldSkip(Class<?> beanClass, String beanName) {
 		// TODO: Consider optimization by caching the list of the aspect names
 		// TODO: Consider optimization by caching the list of the aspect names
+		// 寻找所有候选代理增强点。
 		List<Advisor> candidateAdvisors = findCandidateAdvisors();
 		List<Advisor> candidateAdvisors = findCandidateAdvisors();
 		for (Advisor advisor : candidateAdvisors) {
 		for (Advisor advisor : candidateAdvisors) {
+			// 从前面的代码分析可以看出，如果是 Aop 的动态封装都是基于 InstantiationModelAwarePointcutAdvisorImpl
+			// 也就是 InstantiationModelAwarePointcutAdvisor，自然是继承 PointcutAdvisor
+			// （IntroductionAdvisor 只能用于类级别的拦截，Introduction 型的 Advice；pointcutAdvisor 则都可以）
+			// 如果代理类基于 AspectJPointcutAdvisor  && aspectName==beanName，即当前初始化的类是ApspectJ类本身。则返回true，跳过代理
 			if (advisor instanceof AspectJPointcutAdvisor pointcutAdvisor &&
 			if (advisor instanceof AspectJPointcutAdvisor pointcutAdvisor &&
 					pointcutAdvisor.getAspectName().equals(beanName)) {
 					pointcutAdvisor.getAspectName().equals(beanName)) {
 				return true;
 				return true;
 			}
 			}
 		}
 		}
+		// 父类shouldSkip 判断了文件是否是 .ORIGINAL 后缀，是则跳过。
 		return super.shouldSkip(beanClass, beanName);
 		return super.shouldSkip(beanClass, beanName);
 	}
 	}
 
 

spring-framework-main/spring-aop/src/main/java/org/springframework/aop/config/AopConfigUtils.java

@@ -58,6 +58,7 @@ public abstract class AopConfigUtils {
 
 
 	static {
 	static {
 		// Set up the escalation list...
 		// Set up the escalation list...
+		// 下表越大，优先级越高
 		APC_PRIORITY_LIST.add(InfrastructureAdvisorAutoProxyCreator.class);
 		APC_PRIORITY_LIST.add(InfrastructureAdvisorAutoProxyCreator.class);
 		APC_PRIORITY_LIST.add(AspectJAwareAdvisorAutoProxyCreator.class);
 		APC_PRIORITY_LIST.add(AspectJAwareAdvisorAutoProxyCreator.class);
 		APC_PRIORITY_LIST.add(AnnotationAwareAspectJAutoProxyCreator.class);
 		APC_PRIORITY_LIST.add(AnnotationAwareAspectJAutoProxyCreator.class);
@@ -127,6 +128,7 @@ public abstract class AopConfigUtils {
 		if (registry.containsBeanDefinition(AUTO_PROXY_CREATOR_BEAN_NAME)) {
 		if (registry.containsBeanDefinition(AUTO_PROXY_CREATOR_BEAN_NAME)) {
 			BeanDefinition apcDefinition = registry.getBeanDefinition(AUTO_PROXY_CREATOR_BEAN_NAME);
 			BeanDefinition apcDefinition = registry.getBeanDefinition(AUTO_PROXY_CREATOR_BEAN_NAME);
 			if (!cls.getName().equals(apcDefinition.getBeanClassName())) {
 			if (!cls.getName().equals(apcDefinition.getBeanClassName())) {
+				// 优先级大的为主
 				int currentPriority = findPriorityForClass(apcDefinition.getBeanClassName());
 				int currentPriority = findPriorityForClass(apcDefinition.getBeanClassName());
 				int requiredPriority = findPriorityForClass(cls);
 				int requiredPriority = findPriorityForClass(cls);
 				if (currentPriority < requiredPriority) {
 				if (currentPriority < requiredPriority) {

spring-framework-main/spring-aop/src/main/java/org/springframework/aop/framework/DefaultAdvisorChainFactory.java

@@ -60,6 +60,7 @@ public class DefaultAdvisorChainFactory implements AdvisorChainFactory, Serializ
 		Boolean hasIntroductions = null;
 		Boolean hasIntroductions = null;
 
 
 		for (Advisor advisor : advisors) {
 		for (Advisor advisor : advisors) {
+			// 我们这里的Advisor 都是 PointcutAdvisor 所以这里只分析该内容
 			if (advisor instanceof PointcutAdvisor pointcutAdvisor) {
 			if (advisor instanceof PointcutAdvisor pointcutAdvisor) {
 				// Add it conditionally.
 				// Add it conditionally.
 				if (config.isPreFiltered() || pointcutAdvisor.getPointcut().getClassFilter().matches(actualClass)) {
 				if (config.isPreFiltered() || pointcutAdvisor.getPointcut().getClassFilter().matches(actualClass)) {
@@ -74,12 +75,15 @@ public class DefaultAdvisorChainFactory implements AdvisorChainFactory, Serializ
 					else {
 					else {
 						match = mm.matches(method, actualClass);
 						match = mm.matches(method, actualClass);
 					}
 					}
+					// 如果代理规则与当前类匹配
 					if (match) {
 					if (match) {
+						// 进行转化注册
 						MethodInterceptor[] interceptors = registry.getInterceptors(advisor);
 						MethodInterceptor[] interceptors = registry.getInterceptors(advisor);
 						if (mm.isRuntime()) {
 						if (mm.isRuntime()) {
 							// Creating a new object instance in the getInterceptors() method
 							// Creating a new object instance in the getInterceptors() method
 							// isn't a problem as we normally cache created chains.
 							// isn't a problem as we normally cache created chains.
 							for (MethodInterceptor interceptor : interceptors) {
 							for (MethodInterceptor interceptor : interceptors) {
+								// 封装成 InterceptorAndDynamicMethodMatcher
 								interceptorList.add(new InterceptorAndDynamicMethodMatcher(interceptor, mm));
 								interceptorList.add(new InterceptorAndDynamicMethodMatcher(interceptor, mm));
 							}
 							}
 						}
 						}

spring-framework-main/spring-aop/src/main/java/org/springframework/aop/framework/JdkDynamicAopProxy.java

@@ -108,7 +108,9 @@ final class JdkDynamicAopProxy implements AopProxy, InvocationHandler, Serializa
 			throw new AopConfigException("No advisors and no TargetSource specified");
 			throw new AopConfigException("No advisors and no TargetSource specified");
 		}
 		}
 		this.advised = config;
 		this.advised = config;
+		// 分析出要代理的接口
 		this.proxiedInterfaces = AopProxyUtils.completeProxiedInterfaces(this.advised, true);
 		this.proxiedInterfaces = AopProxyUtils.completeProxiedInterfaces(this.advised, true);
+		// 设置代理属性
 		findDefinedEqualsAndHashCodeMethods(this.proxiedInterfaces);
 		findDefinedEqualsAndHashCodeMethods(this.proxiedInterfaces);
 	}
 	}
 
 
@@ -188,7 +190,9 @@ final class JdkDynamicAopProxy implements AopProxy, InvocationHandler, Serializa
 			}
 			}
 
 
 			Object retVal;
 			Object retVal;
-			// 是否暴露代理对象。有时候目标对象内部的自我调用将无法实施切面中的增强，则需要通过此属性暴露
+			// 如果exposeProxy属性值为true，则将代理对象暴露到ThreadLocal中
+			// exposeProxy是通过注解@EnableAspectJAutoProxy(exposeProxy = true)进行指定的，如果配置为true,
+			// 则可以使用AopContext.currentProxy()获取到代理对象. 在Spring事务方法自调用的时候经常使用到.
 			if (this.advised.exposeProxy) {
 			if (this.advised.exposeProxy) {
 				// Make invocation available if necessary.
 				// Make invocation available if necessary.
 				oldProxy = AopContext.setCurrentProxy(proxy);
 				oldProxy = AopContext.setCurrentProxy(proxy);
@@ -218,7 +222,7 @@ final class JdkDynamicAopProxy implements AopProxy, InvocationHandler, Serializa
 			else {
 			else {
 				// We need to create a method invocation...
 				// We need to create a method invocation...
 				// 否则构建一个新的 方法调用对象 ReflectiveMethodInvocation
 				// 否则构建一个新的 方法调用对象 ReflectiveMethodInvocation
-				// 以便于使用proceed 方法进行链接表用拦截器
+				// 以便于使用 proceed 方法进行链接表用拦截器
 				MethodInvocation invocation =
 				MethodInvocation invocation =
 						new ReflectiveMethodInvocation(proxy, target, method, args, targetClass, chain);
 						new ReflectiveMethodInvocation(proxy, target, method, args, targetClass, chain);
 				// Proceed to the joinpoint through the interceptor chain.
 				// Proceed to the joinpoint through the interceptor chain.

spring-framework-main/spring-aop/src/main/java/org/springframework/aop/framework/ReflectiveMethodInvocation.java

@@ -159,7 +159,7 @@ public class ReflectiveMethodInvocation implements ProxyMethodInvocation, Clonea
 	@Nullable
 	@Nullable
 	public Object proceed() throws Throwable {
 	public Object proceed() throws Throwable {
 		// We start with an index of -1 and increment early.
 		// We start with an index of -1 and increment early.
-		// 执行完所有增强后执行切点方法
+		// 执行完所有增强后执行切点方法，利用索引达到链式访问
 		if (this.currentInterceptorIndex == this.interceptorsAndDynamicMethodMatchers.size() - 1) {
 		if (this.currentInterceptorIndex == this.interceptorsAndDynamicMethodMatchers.size() - 1) {
 			return invokeJoinpoint();
 			return invokeJoinpoint();
 		}
 		}

spring-framework-main/spring-aop/src/main/java/org/springframework/aop/framework/adapter/DefaultAdvisorAdapterRegistry.java

@@ -82,9 +82,12 @@ public class DefaultAdvisorAdapterRegistry implements AdvisorAdapterRegistry, Se
 	public MethodInterceptor[] getInterceptors(Advisor advisor) throws UnknownAdviceTypeException {
 	public MethodInterceptor[] getInterceptors(Advisor advisor) throws UnknownAdviceTypeException {
 		List<MethodInterceptor> interceptors = new ArrayList<>(3);
 		List<MethodInterceptor> interceptors = new ArrayList<>(3);
 		Advice advice = advisor.getAdvice();
 		Advice advice = advisor.getAdvice();
+		// 如果 Advice 就是MethodInterceptor 类型，则直接保存
 		if (advice instanceof MethodInterceptor) {
 		if (advice instanceof MethodInterceptor) {
 			interceptors.add((MethodInterceptor) advice);
 			interceptors.add((MethodInterceptor) advice);
 		}
 		}
+		// 否则寻找合适的适配器进行转换。
+		// 这里的适配器有三个，分别是`AfterReturningAdviceAdapter`、`MethodBeforeAdviceAdapter`、`ThrowsAdviceAdapter`
 		for (AdvisorAdapter adapter : this.adapters) {
 		for (AdvisorAdapter adapter : this.adapters) {
 			if (adapter.supportsAdvice(advice)) {
 			if (adapter.supportsAdvice(advice)) {
 				interceptors.add(adapter.getInterceptor(advisor));
 				interceptors.add(adapter.getInterceptor(advisor));

spring-framework-main/spring-aop/src/main/java/org/springframework/aop/framework/autoproxy/AbstractAdvisorAutoProxyCreator.java

@@ -93,9 +93,10 @@ public abstract class AbstractAdvisorAutoProxyCreator extends AbstractAutoProxyC
 	 * @see #extendAdvisors
 	 * @see #extendAdvisors
 	 */
 	 */
 	protected List<Advisor> findEligibleAdvisors(Class<?> beanClass, String beanName) {
 	protected List<Advisor> findEligibleAdvisors(Class<?> beanClass, String beanName) {
-		// 获取所有的增强
+		// 获取所有的增强（缓存中只有 name 字符串，需要 get，若没有初始化要先初始化)
+		// 另外子类会解析表达式等切面
 		List<Advisor> candidateAdvisors = findCandidateAdvisors();
 		List<Advisor> candidateAdvisors = findCandidateAdvisors();
-		// 寻找增强中适用于bean的增强并应用
+		// 寻找增强中适用于 bean 的增强并应用
 		// 搜索给定的候选增强以查找可以应用于指定 bean 的所有增强。
 		// 搜索给定的候选增强以查找可以应用于指定 bean 的所有增强。
 		List<Advisor> eligibleAdvisors = findAdvisorsThatCanApply(candidateAdvisors, beanClass, beanName);
 		List<Advisor> eligibleAdvisors = findAdvisorsThatCanApply(candidateAdvisors, beanClass, beanName);
 		// 在链表首部，添加增强链增强
 		// 在链表首部，添加增强链增强

spring-framework-main/spring-aop/src/main/java/org/springframework/aop/framework/autoproxy/AbstractAutoProxyCreator.java

@@ -250,9 +250,11 @@ public abstract class AbstractAutoProxyCreator extends ProxyProcessorSupport
 		Object cacheKey = getCacheKey(beanClass, beanName);
 		Object cacheKey = getCacheKey(beanClass, beanName);
 
 
 		if (!StringUtils.hasLength(beanName) || !this.targetSourcedBeans.contains(beanName)) {
 		if (!StringUtils.hasLength(beanName) || !this.targetSourcedBeans.contains(beanName)) {
+			// 已经代理过
 			if (this.advisedBeans.containsKey(cacheKey)) {
 			if (this.advisedBeans.containsKey(cacheKey)) {
 				return null;
 				return null;
 			}
 			}
+			// 基础类或代理本身则跳过
 			if (isInfrastructureClass(beanClass) || shouldSkip(beanClass, beanName)) {
 			if (isInfrastructureClass(beanClass) || shouldSkip(beanClass, beanName)) {
 				this.advisedBeans.put(cacheKey, Boolean.FALSE);
 				this.advisedBeans.put(cacheKey, Boolean.FALSE);
 				return null;
 				return null;
@@ -262,6 +264,9 @@ public abstract class AbstractAutoProxyCreator extends ProxyProcessorSupport
 		// Create proxy here if we have a custom TargetSource.
 		// Create proxy here if we have a custom TargetSource.
 		// Suppresses unnecessary default instantiation of the target bean:
 		// Suppresses unnecessary default instantiation of the target bean:
 		// The TargetSource will handle target instances in a custom fashion.
 		// The TargetSource will handle target instances in a custom fashion.
+
+		// 获取封装当前 bean 的 TargetSource 对象，如果不存在，则直接退出当前方法，否则从 TargetSource
+		// 中获取当前 bean 对象，并且判断是否需要将切面逻辑应用在当前 bean 上。
 		TargetSource targetSource = getCustomTargetSource(beanClass, beanName);
 		TargetSource targetSource = getCustomTargetSource(beanClass, beanName);
 		if (targetSource != null) {
 		if (targetSource != null) {
 			if (StringUtils.hasLength(beanName)) {
 			if (StringUtils.hasLength(beanName)) {
@@ -339,7 +344,9 @@ public abstract class AbstractAutoProxyCreator extends ProxyProcessorSupport
 			return bean;
 			return bean;
 		}
 		}
 		// 给定的bean是否代表一个基础设施类，基础设施类不应代理，或者配置了指定的bean不需要自动代理
 		// 给定的bean是否代表一个基础设施类，基础设施类不应代理，或者配置了指定的bean不需要自动代理
+		// 不能代理基础类或者代理本身
 		if (isInfrastructureClass(bean.getClass()) || shouldSkip(bean.getClass(), beanName)) {
 		if (isInfrastructureClass(bean.getClass()) || shouldSkip(bean.getClass(), beanName)) {
+			// 不代理也要记录下来
 			this.advisedBeans.put(cacheKey, Boolean.FALSE);
 			this.advisedBeans.put(cacheKey, Boolean.FALSE);
 			return bean;
 			return bean;
 		}
 		}
@@ -454,7 +461,7 @@ public abstract class AbstractAutoProxyCreator extends ProxyProcessorSupport
 		// 获取当前类中属性
 		// 获取当前类中属性
 		proxyFactory.copyFrom(this);
 		proxyFactory.copyFrom(this);
 
 
-		// 决定对于给定的 bean 是否应该使用 targetClass 属性 而不是他的代理接口
+		// 决定对于给定的 bean 是否应该使用 targetClass 属性而不是他的代理接口
 		// 检查 ProxyTargetClass 设置以及 preserveTargetClass
 		// 检查 ProxyTargetClass 设置以及 preserveTargetClass
 		if (proxyFactory.isProxyTargetClass()) {
 		if (proxyFactory.isProxyTargetClass()) {
 			// Explicit handling of JDK proxy targets and lambdas (for introduction advice scenarios)
 			// Explicit handling of JDK proxy targets and lambdas (for introduction advice scenarios)
@@ -477,6 +484,7 @@ public abstract class AbstractAutoProxyCreator extends ProxyProcessorSupport
 			}
 			}
 		}
 		}
 
 
+		// 不仅之前解析的，也有可能用户注入了拦截器，都要添加进去
 		Advisor[] advisors = buildAdvisors(beanName, specificInterceptors);
 		Advisor[] advisors = buildAdvisors(beanName, specificInterceptors);
 		// 加入增强器
 		// 加入增强器
 		proxyFactory.addAdvisors(advisors);
 		proxyFactory.addAdvisors(advisors);
@@ -580,6 +588,7 @@ public abstract class AbstractAutoProxyCreator extends ProxyProcessorSupport
 		BeanFactory bf = this.beanFactory;
 		BeanFactory bf = this.beanFactory;
 		ConfigurableBeanFactory cbf = (bf instanceof ConfigurableBeanFactory ? (ConfigurableBeanFactory) bf : null);
 		ConfigurableBeanFactory cbf = (bf instanceof ConfigurableBeanFactory ? (ConfigurableBeanFactory) bf : null);
 		List<Advisor> advisors = new ArrayList<>();
 		List<Advisor> advisors = new ArrayList<>();
+		// 将 interceptorNames 获取到的拦截器保存起来，并返回。用户会通过 set 方法添加
 		for (String beanName : this.interceptorNames) {
 		for (String beanName : this.interceptorNames) {
 			if (cbf == null || !cbf.isCurrentlyInCreation(beanName)) {
 			if (cbf == null || !cbf.isCurrentlyInCreation(beanName)) {
 				Assert.state(bf != null, "BeanFactory required for resolving interceptor names");
 				Assert.state(bf != null, "BeanFactory required for resolving interceptor names");

spring-framework-main/spring-aop/src/main/java/org/springframework/aop/framework/autoproxy/BeanFactoryAdvisorRetrievalHelper.java

@@ -79,7 +79,7 @@ public class BeanFactoryAdvisorRetrievalHelper {
 			return new ArrayList<>();
 			return new ArrayList<>();
 		}
 		}
 
 
-		// 遍历所有的beanName找到对应的增强方法
+		// 遍历所有的 beanName 找到对应的增强方法
 		List<Advisor> advisors = new ArrayList<>();
 		List<Advisor> advisors = new ArrayList<>();
 		for (String name : advisorNames) {
 		for (String name : advisorNames) {
 			// 合法情况
 			// 合法情况

spring-framework-main/spring-aop/src/main/java/org/springframework/aop/support/AopUtils.java

@@ -227,12 +227,14 @@ public abstract class AopUtils {
 			return false;
 			return false;
 		}
 		}
 
 
+		// 获取切点的方法匹配器
 		MethodMatcher methodMatcher = pc.getMethodMatcher();
 		MethodMatcher methodMatcher = pc.getMethodMatcher();
 		if (methodMatcher == MethodMatcher.TRUE) {
 		if (methodMatcher == MethodMatcher.TRUE) {
 			// No need to iterate the methods if we're matching any method anyway...
 			// No need to iterate the methods if we're matching any method anyway...
 			return true;
 			return true;
 		}
 		}
 
 
+		// 这里 introductionAwareMethodMatcher 的实现是 AspectJExpressionPointcut
 		IntroductionAwareMethodMatcher introductionAwareMethodMatcher = null;
 		IntroductionAwareMethodMatcher introductionAwareMethodMatcher = null;
 		if (methodMatcher instanceof IntroductionAwareMethodMatcher) {
 		if (methodMatcher instanceof IntroductionAwareMethodMatcher) {
 			introductionAwareMethodMatcher = (IntroductionAwareMethodMatcher) methodMatcher;
 			introductionAwareMethodMatcher = (IntroductionAwareMethodMatcher) methodMatcher;
@@ -246,8 +248,11 @@ public abstract class AopUtils {
 
 
 		for (Class<?> clazz : classes) {
 		for (Class<?> clazz : classes) {
 			Method[] methods = ReflectionUtils.getAllDeclaredMethods(clazz);
 			Method[] methods = ReflectionUtils.getAllDeclaredMethods(clazz);
+			// 获取当前bean的所有方法
 			for (Method method : methods) {
 			for (Method method : methods) {
+				// 在这里判断方法是否匹配
 				if (introductionAwareMethodMatcher != null ?
 				if (introductionAwareMethodMatcher != null ?
+						// 这里调用 AspectJExpressionPointcut#matches
 						introductionAwareMethodMatcher.matches(method, targetClass, hasIntroductions) :
 						introductionAwareMethodMatcher.matches(method, targetClass, hasIntroductions) :
 						methodMatcher.matches(method, targetClass)) {
 						methodMatcher.matches(method, targetClass)) {
 					return true;
 					return true;

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

@@ -321,7 +321,7 @@ class ConstructorResolver {
 					ambiguousConstructors = null;
 					ambiguousConstructors = null;
 				}
 				}
 				else if (constructorToUse != null && typeDiffWeight == minTypeDiffWeight) {
 				else if (constructorToUse != null && typeDiffWeight == minTypeDiffWeight) {
-					// 如果 已经找到候选构造函数，且当前这个构造函数也有相同的类似度则保存到 ambiguousConstructors 中。后面用于抛出异常
+					// 如果已经找到候选构造函数，且当前这个构造函数也有相同的类似度则保存到 ambiguousConstructors 中。后面用于抛出异常
 					if (ambiguousConstructors == null) {
 					if (ambiguousConstructors == null) {
 						ambiguousConstructors = new LinkedHashSet<>();
 						ambiguousConstructors = new LinkedHashSet<>();
 						ambiguousConstructors.add(constructorToUse);
 						ambiguousConstructors.add(constructorToUse);

spring-framework-main/spring-context/src/main/java/org/springframework/context/annotation/AspectJAutoProxyRegistrar.java

@@ -42,14 +42,18 @@ class AspectJAutoProxyRegistrar implements ImportBeanDefinitionRegistrar {
 	public void registerBeanDefinitions(
 	public void registerBeanDefinitions(
 			AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
 			AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
 
 
+		// 注册 AspectJ 注释自动代理创建器。这里注册的自动代理创建器 Aop 实现的核心。
 		AopConfigUtils.registerAspectJAnnotationAutoProxyCreatorIfNecessary(registry);
 		AopConfigUtils.registerAspectJAnnotationAutoProxyCreatorIfNecessary(registry);
 
 
+		// 获取 @EnableAspectJAutoProxy 注解
 		AnnotationAttributes enableAspectJAutoProxy =
 		AnnotationAttributes enableAspectJAutoProxy =
 				AnnotationConfigUtils.attributesFor(importingClassMetadata, EnableAspectJAutoProxy.class);
 				AnnotationConfigUtils.attributesFor(importingClassMetadata, EnableAspectJAutoProxy.class);
 		if (enableAspectJAutoProxy != null) {
 		if (enableAspectJAutoProxy != null) {
+			// 解析 proxyTargetClass 属性（是否使用cglib代理）
 			if (enableAspectJAutoProxy.getBoolean("proxyTargetClass")) {
 			if (enableAspectJAutoProxy.getBoolean("proxyTargetClass")) {
 				AopConfigUtils.forceAutoProxyCreatorToUseClassProxying(registry);
 				AopConfigUtils.forceAutoProxyCreatorToUseClassProxying(registry);
 			}
 			}
+			//  解析 exposeProxy 属性（是否暴露代理对象）
 			if (enableAspectJAutoProxy.getBoolean("exposeProxy")) {
 			if (enableAspectJAutoProxy.getBoolean("exposeProxy")) {
 				AopConfigUtils.forceAutoProxyCreatorToExposeProxy(registry);
 				AopConfigUtils.forceAutoProxyCreatorToExposeProxy(registry);
 			}
 			}

spring-framework-main/spring-context/src/main/java/org/springframework/context/annotation/ConfigurationClassBeanDefinitionReader.java

@@ -153,6 +153,7 @@ class ConfigurationClassBeanDefinitionReader {
 		}
 		}
 
 
 		loadBeanDefinitionsFromImportedResources(configClass.getImportedResources());
 		loadBeanDefinitionsFromImportedResources(configClass.getImportedResources());
+		// AOP 自动代理创建器的注册就在这一步
 		loadBeanDefinitionsFromRegistrars(configClass.getImportBeanDefinitionRegistrars());
 		loadBeanDefinitionsFromRegistrars(configClass.getImportBeanDefinitionRegistrars());
 	}
 	}
 
 
@@ -160,6 +161,7 @@ class ConfigurationClassBeanDefinitionReader {
 	 * Register the {@link Configuration} class itself as a bean definition.
 	 * Register the {@link Configuration} class itself as a bean definition.
 	 */
 	 */
 	private void registerBeanDefinitionForImportedConfigurationClass(ConfigurationClass configClass) {
 	private void registerBeanDefinitionForImportedConfigurationClass(ConfigurationClass configClass) {
+		// 就是将引入的配置类注册为 BeanDefinition
 		AnnotationMetadata metadata = configClass.getMetadata();
 		AnnotationMetadata metadata = configClass.getMetadata();
 		AnnotatedGenericBeanDefinition configBeanDef = new AnnotatedGenericBeanDefinition(metadata);
 		AnnotatedGenericBeanDefinition configBeanDef = new AnnotatedGenericBeanDefinition(metadata);
 
 
@@ -169,7 +171,9 @@ class ConfigurationClassBeanDefinitionReader {
 		AnnotationConfigUtils.processCommonDefinitionAnnotations(configBeanDef, metadata);
 		AnnotationConfigUtils.processCommonDefinitionAnnotations(configBeanDef, metadata);
 
 
 		BeanDefinitionHolder definitionHolder = new BeanDefinitionHolder(configBeanDef, configBeanName);
 		BeanDefinitionHolder definitionHolder = new BeanDefinitionHolder(configBeanDef, configBeanName);
+		// 创建代理，根据 scopeMetadata 的代理模式。默认不创建代理。
 		definitionHolder = AnnotationConfigUtils.applyScopedProxyMode(scopeMetadata, definitionHolder, this.registry);
 		definitionHolder = AnnotationConfigUtils.applyScopedProxyMode(scopeMetadata, definitionHolder, this.registry);
+		// 注册了 BeanBeanDefinition
 		this.registry.registerBeanDefinition(definitionHolder.getBeanName(), definitionHolder.getBeanDefinition());
 		this.registry.registerBeanDefinition(definitionHolder.getBeanName(), definitionHolder.getBeanDefinition());
 		configClass.setBeanName(configBeanName);
 		configClass.setBeanName(configBeanName);
 
 

spring-framework-main/spring-context/src/main/java/org/springframework/context/annotation/ConfigurationClassParser.java

@@ -246,7 +246,7 @@ class ConfigurationClassParser {
 			else {
 			else {
 				// Explicit bean definition found, probably replacing an import.
 				// Explicit bean definition found, probably replacing an import.
 				// Let's remove the old one and go with the new one.
 				// Let's remove the old one and go with the new one.
-				// 是注入的配置类优先级高于引入的配置类
+				// 主动注入的配置类优先级高于引入的配置类
 				// 如果当前的配置类不是引入的，则移除之前的配置类，重新解析
 				// 如果当前的配置类不是引入的，则移除之前的配置类，重新解析
 				this.configurationClasses.remove(configClass);
 				this.configurationClasses.remove(configClass);
 				this.knownSuperclasses.values().removeIf(configClass::equals);
 				this.knownSuperclasses.values().removeIf(configClass::equals);
@@ -283,10 +283,12 @@ class ConfigurationClassParser {
 		}
 		}
 
 
 		// Process any @PropertySource annotations
 		// Process any @PropertySource annotations
+		// 去重后遍历 PropertySource 注解所指向的属性。注意:两个注解@PropertySources 和 @PropertySource。
 		for (AnnotationAttributes propertySource : AnnotationConfigUtils.attributesForRepeatable(
 		for (AnnotationAttributes propertySource : AnnotationConfigUtils.attributesForRepeatable(
 				sourceClass.getMetadata(), PropertySources.class,
 				sourceClass.getMetadata(), PropertySources.class,
 				org.springframework.context.annotation.PropertySource.class)) {
 				org.springframework.context.annotation.PropertySource.class)) {
 			if (this.environment instanceof ConfigurableEnvironment) {
 			if (this.environment instanceof ConfigurableEnvironment) {
+				// 解析
 				processPropertySource(propertySource);
 				processPropertySource(propertySource);
 			}
 			}
 			else {
 			else {
@@ -296,12 +298,15 @@ class ConfigurationClassParser {
 		}
 		}
 
 
 		// Process any @ComponentScan annotations
 		// Process any @ComponentScan annotations
+		// 将 @ComponentScans 中的多个 @ComponentScan 解析出来封装成一个一个AnnotationAttributes对象
 		Set<AnnotationAttributes> componentScans = AnnotationConfigUtils.attributesForRepeatable(
 		Set<AnnotationAttributes> componentScans = AnnotationConfigUtils.attributesForRepeatable(
 				sourceClass.getMetadata(), ComponentScans.class, ComponentScan.class);
 				sourceClass.getMetadata(), ComponentScans.class, ComponentScan.class);
+		// 如果当前配置类被 @componentScans 或 @componentScan 注解修饰 && 不应跳过
 		if (!componentScans.isEmpty() &&
 		if (!componentScans.isEmpty() &&
 				!this.conditionEvaluator.shouldSkip(sourceClass.getMetadata(), ConfigurationPhase.REGISTER_BEAN)) {
 				!this.conditionEvaluator.shouldSkip(sourceClass.getMetadata(), ConfigurationPhase.REGISTER_BEAN)) {
 			for (AnnotationAttributes componentScan : componentScans) {
 			for (AnnotationAttributes componentScan : componentScans) {
 				// The config class is annotated with @ComponentScan -> perform the scan immediately
 				// The config class is annotated with @ComponentScan -> perform the scan immediately
+				// 直接执行扫描，根据指定路径扫描出来bean。
 				Set<BeanDefinitionHolder> scannedBeanDefinitions =
 				Set<BeanDefinitionHolder> scannedBeanDefinitions =
 						this.componentScanParser.parse(componentScan, sourceClass.getMetadata().getClassName());
 						this.componentScanParser.parse(componentScan, sourceClass.getMetadata().getClassName());
 				// Check the set of scanned definitions for any further config classes and parse recursively if needed
 				// Check the set of scanned definitions for any further config classes and parse recursively if needed
@@ -310,6 +315,7 @@ class ConfigurationClassParser {
 					if (bdCand == null) {
 					if (bdCand == null) {
 						bdCand = holder.getBeanDefinition();
 						bdCand = holder.getBeanDefinition();
 					}
 					}
+					// 检测如果是配置类，则递归调用 parse 解析。
 					if (ConfigurationClassUtils.checkConfigurationClassCandidate(bdCand, this.metadataReaderFactory)) {
 					if (ConfigurationClassUtils.checkConfigurationClassCandidate(bdCand, this.metadataReaderFactory)) {
 						parse(bdCand.getBeanClassName(), holder.getBeanName());
 						parse(bdCand.getBeanClassName(), holder.getBeanName());
 					}
 					}
@@ -318,9 +324,11 @@ class ConfigurationClassParser {
 		}
 		}
 
 
 		// Process any @Import annotations
 		// Process any @Import annotations
+		// @Import、@ImportSelector、@ImportBeanDefinitionRegistrar都在这儿
 		processImports(configClass, sourceClass, getImports(sourceClass), filter, true);
 		processImports(configClass, sourceClass, getImports(sourceClass), filter, true);
 
 
 		// Process any @ImportResource annotations
 		// Process any @ImportResource annotations
+		// @ImportResource 直接保存到 configClass 中。
 		AnnotationAttributes importResource =
 		AnnotationAttributes importResource =
 				AnnotationConfigUtils.attributesFor(sourceClass.getMetadata(), ImportResource.class);
 				AnnotationConfigUtils.attributesFor(sourceClass.getMetadata(), ImportResource.class);
 		if (importResource != null) {
 		if (importResource != null) {
@@ -333,12 +341,14 @@ class ConfigurationClassParser {
 		}
 		}
 
 
 		// Process individual @Bean methods
 		// Process individual @Bean methods
+		// 直接保存到 configClass 的中
 		Set<MethodMetadata> beanMethods = retrieveBeanMethodMetadata(sourceClass);
 		Set<MethodMetadata> beanMethods = retrieveBeanMethodMetadata(sourceClass);
 		for (MethodMetadata methodMetadata : beanMethods) {
 		for (MethodMetadata methodMetadata : beanMethods) {
 			configClass.addBeanMethod(new BeanMethod(methodMetadata, configClass));
 			configClass.addBeanMethod(new BeanMethod(methodMetadata, configClass));
 		}
 		}
 
 
 		// Process default methods on interfaces
 		// Process default methods on interfaces
+		// 检测配置类实现的接口中的默认方法是否被@Bean修饰
 		processInterfaces(configClass, sourceClass);
 		processInterfaces(configClass, sourceClass);
 
 
 		// Process superclass, if any
 		// Process superclass, if any
@@ -375,7 +385,7 @@ class ConfigurationClassParser {
 				}
 				}
 			}
 			}
 			OrderComparator.sort(candidates);
 			OrderComparator.sort(candidates);
-			// dfs 解析内部类
+			// dfs 解析内部类（开始前要注意防止循环导入）
 			for (SourceClass candidate : candidates) {
 			for (SourceClass candidate : candidates) {
 				if (this.importStack.contains(configClass)) {
 				if (this.importStack.contains(configClass)) {
 					this.problemReporter.error(new CircularImportProblem(configClass, this.importStack));
 					this.problemReporter.error(new CircularImportProblem(configClass, this.importStack));
@@ -472,8 +482,10 @@ class ConfigurationClassParser {
 
 
 		for (String location : locations) {
 		for (String location : locations) {
 			try {
 			try {
+				// 解决占位符，获取真正路径
 				String resolvedLocation = this.environment.resolveRequiredPlaceholders(location);
 				String resolvedLocation = this.environment.resolveRequiredPlaceholders(location);
 				Resource resource = this.resourceLoader.getResource(resolvedLocation);
 				Resource resource = this.resourceLoader.getResource(resolvedLocation);
+				// 保存
 				addPropertySource(factory.createPropertySource(name, new EncodedResource(resource, encoding)));
 				addPropertySource(factory.createPropertySource(name, new EncodedResource(resource, encoding)));
 			}
 			}
 			catch (IllegalArgumentException | FileNotFoundException | UnknownHostException | SocketException ex) {
 			catch (IllegalArgumentException | FileNotFoundException | UnknownHostException | SocketException ex) {
@@ -494,6 +506,7 @@ class ConfigurationClassParser {
 		String name = propertySource.getName();
 		String name = propertySource.getName();
 		MutablePropertySources propertySources = ((ConfigurableEnvironment) this.environment).getPropertySources();
 		MutablePropertySources propertySources = ((ConfigurableEnvironment) this.environment).getPropertySources();
 
 
+		// 解决重复问题
 		if (this.propertySourceNames.contains(name)) {
 		if (this.propertySourceNames.contains(name)) {
 			// We've already added a version, we need to extend it
 			// We've already added a version, we need to extend it
 			PropertySource<?> existing = propertySources.get(name);
 			PropertySource<?> existing = propertySources.get(name);
@@ -578,9 +591,11 @@ class ConfigurationClassParser {
 		else {
 		else {
 			this.importStack.push(configClass);
 			this.importStack.push(configClass);
 			try {
 			try {
+				// dfs
 				for (SourceClass candidate : importCandidates) {
 				for (SourceClass candidate : importCandidates) {
 					if (candidate.isAssignable(ImportSelector.class)) {
 					if (candidate.isAssignable(ImportSelector.class)) {
 						// Candidate class is an ImportSelector -> delegate to it to determine imports
 						// Candidate class is an ImportSelector -> delegate to it to determine imports
+						// 判断是否是ImportSelector类型。ImportSelector 则需要调用selectImports 方法来获取需要注入的类。
 						Class<?> candidateClass = candidate.loadClass();
 						Class<?> candidateClass = candidate.loadClass();
 						ImportSelector selector = ParserStrategyUtils.instantiateClass(candidateClass, ImportSelector.class,
 						ImportSelector selector = ParserStrategyUtils.instantiateClass(candidateClass, ImportSelector.class,
 								this.environment, this.resourceLoader, this.registry);
 								this.environment, this.resourceLoader, this.registry);
@@ -594,9 +609,11 @@ class ConfigurationClassParser {
 						else {
 						else {
 							String[] importClassNames = selector.selectImports(currentSourceClass.getMetadata());
 							String[] importClassNames = selector.selectImports(currentSourceClass.getMetadata());
 							Collection<SourceClass> importSourceClasses = asSourceClasses(importClassNames, exclusionFilter);
 							Collection<SourceClass> importSourceClasses = asSourceClasses(importClassNames, exclusionFilter);
+							// 调用 selectImports 方法获取需要引入的类，并递归再次处理。
 							processImports(configClass, currentSourceClass, importSourceClasses, exclusionFilter, false);
 							processImports(configClass, currentSourceClass, importSourceClasses, exclusionFilter, false);
 						}
 						}
 					}
 					}
+					// 如果是 ImportBeanDefinitionRegistrar 类型，则委托它注册其他bean定义
 					else if (candidate.isAssignable(ImportBeanDefinitionRegistrar.class)) {
 					else if (candidate.isAssignable(ImportBeanDefinitionRegistrar.class)) {
 						// Candidate class is an ImportBeanDefinitionRegistrar ->
 						// Candidate class is an ImportBeanDefinitionRegistrar ->
 						// delegate to it to register additional bean definitions
 						// delegate to it to register additional bean definitions
@@ -609,6 +626,7 @@ class ConfigurationClassParser {
 					else {
 					else {
 						// Candidate class not an ImportSelector or ImportBeanDefinitionRegistrar ->
 						// Candidate class not an ImportSelector or ImportBeanDefinitionRegistrar ->
 						// process it as an @Configuration class
 						// process it as an @Configuration class
+						// 否则递归处理需要引入的类。
 						this.importStack.registerImport(
 						this.importStack.registerImport(
 								currentSourceClass.getMetadata(), candidate.getMetadata().getClassName());
 								currentSourceClass.getMetadata(), candidate.getMetadata().getClassName());
 						processConfigurationClass(candidate.asConfigClass(configClass), exclusionFilter);
 						processConfigurationClass(candidate.asConfigClass(configClass), exclusionFilter);

spring-framework-main/spring-context/src/main/java/org/springframework/context/annotation/ConfigurationClassUtils.java

@@ -139,7 +139,6 @@ abstract class ConfigurationClassUtils {
 			beanDef.setAttribute(CONFIGURATION_CLASS_ATTRIBUTE, CONFIGURATION_CLASS_FULL);
 			beanDef.setAttribute(CONFIGURATION_CLASS_ATTRIBUTE, CONFIGURATION_CLASS_FULL);
 		}
 		}
 		// 如果被 @Configuration 修饰 && isConfigurationCandidate(metadata) = true
 		// 如果被 @Configuration 修饰 && isConfigurationCandidate(metadata) = true
-		// 关于 isConfigurationCandidate(metadata) 的解析在下面
 		else if (config != null || isConfigurationCandidate(metadata)) {
 		else if (config != null || isConfigurationCandidate(metadata)) {
 			// 设置 CONFIGURATION_CLASS_ATTRIBUTE 为 lite
 			// 设置 CONFIGURATION_CLASS_ATTRIBUTE 为 lite
 			beanDef.setAttribute(CONFIGURATION_CLASS_ATTRIBUTE, CONFIGURATION_CLASS_LITE);
 			beanDef.setAttribute(CONFIGURATION_CLASS_ATTRIBUTE, CONFIGURATION_CLASS_LITE);