Spring AOP配置标簽解析

準備

• Spring版本：5.0.8

解析過程

開啟

Spring AOP

注解自動代理需要配置标簽

<aop:aspectj-autoproxy/>

，檢視

spring-aop:5.0.8.RELEASE\META-INF\spring.handlers

檔案，配置以下内容：

下面以

AopNamespaceHandler

為入口，對解析過程源碼進行分析

// AopNamespaceHandler
public void init() {
    this.registerBeanDefinitionParser("config", new ConfigBeanDefinitionParser());
    // 注冊aspectj-autoproxy解析器
    this.registerBeanDefinitionParser("aspectj-autoproxy", new AspectJAutoProxyBeanDefinitionParser());
    this.registerBeanDefinitionDecorator("scoped-proxy", new ScopedProxyBeanDefinitionDecorator());
    this.registerBeanDefinitionParser("spring-configured", new SpringConfiguredBeanDefinitionParser());
}
           

通過

AspectJAutoProxyBeanDefinitionParser. parse()

對

<aop:aspectj-autoproxy/>

标簽進行解析

// AspectJAutoProxyBeanDefinitionParser
public BeanDefinition parse(Element element, ParserContext parserContext) {
// 注冊AspectJAnnotationAutoProxyCreator
    AopNamespaceUtils.registerAspectJAnnotationAutoProxyCreatorIfNecessary(parserContext, element);
    // 針對子元素的解析
this.extendBeanDefinition(element, parserContext);
    return null;
}
           

// AopNamespaceUtils
public static void registerAspectJAnnotationAutoProxyCreatorIfNecessary(ParserContext parserContext, Element sourceElement) {
    // 注冊AspectJAnnotationAutoProxyCreator
    BeanDefinition beanDefinition = 
AopConfigUtils.registerAspectJAnnotationAutoProxyCreatorIfNecessary(parserContext.getRegistry(), parserContext.extractSource(sourceElement));
// 對proxy-target-class及expose-proxy屬性的處理
    useClassProxyingIfNecessary(parserContext.getRegistry(), sourceElement);
    // 注冊元件并通知 便于監聽器做進一步處理
registerComponentIfNecessary(beanDefinition, parserContext);
}
           

// AopConfigUtils
public static BeanDefinition registerAspectJAnnotationAutoProxyCreatorIfNecessary(BeanDefinitionRegistry registry, @Nullable Object source) {
    return registerOrEscalateApcAsRequired(AnnotationAwareAspectJAutoProxyCreator.class, registry, source);
}
           

// AopConfigUtils
private static BeanDefinition registerOrEscalateApcAsRequired(Class<?> cls, BeanDefinitionRegistry registry, @Nullable Object source) {
    Assert.notNull(registry, "BeanDefinitionRegistry must not be null");
// 如果已經存在自動代理建立器 且 存在的自動代理建立器與現在的不一緻需要根據優先級來判斷需要使用那一個
    if (registry.containsBeanDefinition("org.springframework.aop.config.internalAutoProxyCreator")) {
        BeanDefinition apcDefinition = registry.getBeanDefinition("org.springframework.aop.config.internalAutoProxyCreator");
        if (!cls.getName().equals(apcDefinition.getBeanClassName())) {
        // 擷取已存在自動代理建立器優先級
            int currentPriority = findPriorityForClass(apcDefinition.getBeanClassName());
        // 擷取本次要建立自動代理建立器優先級
            int requiredPriority = findPriorityForClass(cls);
        // 使用優先級高的自動代理建立器
            if (currentPriority < requiredPriority) {
                apcDefinition.setBeanClassName(cls.getName());
            }
        }
        // 已存在自動代理建立器與将要建立的一緻 則無需再次建立
        return null;
    } else {
        RootBeanDefinition beanDefinition = new RootBeanDefinition(cls);
        beanDefinition.setSource(source);
        beanDefinition.getPropertyValues().add("order", -);
        beanDefinition.setRole();
    // 注冊自動代理建立器
        registry.registerBeanDefinition("org.springframework.aop.config.internalAutoProxyCreator", beanDefinition);
        return beanDefinition;
    }
}
           

擷取優先級方法

findPriorityForClass()

方法通過維護的集合

APC_PRIORITY_LIST

索引值來确定優先級，索引值越小優先級越高。

// AopConfigUtils
private static final List<Class<?>> APC_PRIORITY_LIST = new ArrayList<>();

static {
   APC_PRIORITY_LIST.add(InfrastructureAdvisorAutoProxyCreator.class);
   APC_PRIORITY_LIST.add(AspectJAwareAdvisorAutoProxyCreator.class);
   APC_PRIORITY_LIST.add(AnnotationAwareAspectJAutoProxyCreator.class);
}

private static int findPriorityForClass(Class<?> clazz) {
   return APC_PRIORITY_LIST.indexOf(clazz);
}

private static int findPriorityForClass(@Nullable String className) {
   for (int i = ; i < APC_PRIORITY_LIST.size(); i++) {
      Class<?> clazz = APC_PRIORITY_LIST.get(i);
      if (clazz.getName().equals(className)) {
         return i;
      }
   }
   throw new IllegalArgumentException(
         "Class name [" + className + "] is not a known auto-proxy creator class");
}
           

注冊完

AnnotationAwareAspectJAutoProxyCreator

之後，通過類繼承圖發現間接實作了

BeanPostProcessor

，而

Spring

會在

bean

初始化是調用

postProcessAfterInitialization()

方法，而改方法實作在其父類

AbstractAutoProxyCreator

中

// AbstractAutoProxyCreator
public Object postProcessAfterInitialization(@Nullable Object bean, String beanName) throws BeansException {
   if (bean != null) {
      Object cacheKey = getCacheKey(bean.getClass(), beanName);
      if (!this.earlyProxyReferences.contains(cacheKey)) {
         return wrapIfNecessary(bean, beanName, cacheKey);
      }
   }
   return bean;
}
           

// AbstractAutoProxyCreator
protected Object wrapIfNecessary(Object bean, String beanName, Object cacheKey) {
   if (StringUtils.hasLength(beanName) && this.targetSourcedBeans.contains(beanName)) {
      return bean;
   }
   //
   if (Boolean.FALSE.equals(this.advisedBeans.get(cacheKey))) {
      return bean;
   }
   // 如果是aop基礎類或配置不需要代理 直接傳回
   if (isInfrastructureClass(bean.getClass()) || shouldSkip(bean.getClass(), beanName)) {
      this.advisedBeans.put(cacheKey, Boolean.FALSE);
      return bean;
   }

   // 擷取bean比對的增強方法
   Object[] specificInterceptors = getAdvicesAndAdvisorsForBean(bean.getClass(), beanName, null);
   if (specificInterceptors != DO_NOT_PROXY) {
      this.advisedBeans.put(cacheKey, Boolean.TRUE);
      // 建立代理
      Object proxy = createProxy(
            bean.getClass(), beanName, specificInterceptors, new SingletonTargetSource(bean));
      this.proxyTypes.put(cacheKey, proxy.getClass());
      return proxy;
   }

   this.advisedBeans.put(cacheKey, Boolean.FALSE);
   return bean;
}
           

// AbstractAdvisorAutoProxyCreator
protected Object[] getAdvicesAndAdvisorsForBean(
      Class<?> beanClass, String beanName, @Nullable TargetSource targetSource) {
   // 查找合适的增強器
   List<Advisor> advisors = findEligibleAdvisors(beanClass, beanName);
   if (advisors.isEmpty()) {
      return DO_NOT_PROXY;
   }
   return advisors.toArray();
}
           

// AbstractAdvisorAutoProxyCreator
protected List<Advisor> findEligibleAdvisors(Class<?> beanClass, String beanName) {
   // 尋找合适的增強器
   List<Advisor> candidateAdvisors = findCandidateAdvisors();
   // 确定增強器能否應用在bean上
   List<Advisor> eligibleAdvisors = findAdvisorsThatCanApply(candidateAdvisors, beanClass, beanName);
   extendAdvisors(eligibleAdvisors);
   if (!eligibleAdvisors.isEmpty()) {
      eligibleAdvisors = sortAdvisors(eligibleAdvisors);
   }
   return eligibleAdvisors;
}
           

// AnnotationAwareAspectJAutoProxyCreator
protected List<Advisor> findCandidateAdvisors() {
   // 擷取父類中其他aop配置
   List<Advisor> advisors = super.findCandidateAdvisors();
   // Build Advisors for all AspectJ aspects in the bean factory.
   if (this.aspectJAdvisorsBuilder != null) {
      // 擷取注解方式aop配置
      advisors.addAll(this.aspectJAdvisorsBuilder.buildAspectJAdvisors());
   }
   return advisors;
}
           

// AbstractAdvisorAutoProxyCreator
protected List<Advisor> findCandidateAdvisors() {
   Assert.state(this.advisorRetrievalHelper != null, "No BeanFactoryAdvisorRetrievalHelper available");
   // 擷取配置為增強器的bean
   return this.advisorRetrievalHelper.findAdvisorBeans();
}
           

// BeanFactoryAdvisorRetrievalHelper
public List<Advisor> findAdvisorBeans() {
   // Determine list of advisor bean names, if not cached already.
   String[] advisorNames = null;
   synchronized (this) {
      advisorNames = this.cachedAdvisorBeanNames;
      if (advisorNames == null) {
         // Do not initialize FactoryBeans here: We need to leave all regular beans
         // uninitialized to let the auto-proxy creator apply to them!
         // 保持正常bean未初始化 而讓自動代理建立器去處理
         advisorNames = BeanFactoryUtils.beanNamesForTypeIncludingAncestors(
               this.beanFactory, Advisor.class, true, false);
         this.cachedAdvisorBeanNames = advisorNames;
      }
   }
   if (advisorNames.length == ) {
      return new LinkedList<>();
   }

   List<Advisor> advisors = new LinkedList<>();
   for (String name : advisorNames) {
      if (isEligibleBean(name)) {
         if (this.beanFactory.isCurrentlyInCreation(name)) {
            if (logger.isDebugEnabled()) {
               logger.debug("Skipping currently created advisor '" + name + "'");
            }
         }
         else {
            try {
               // 添加至增強器清單
               advisors.add(this.beanFactory.getBean(name, Advisor.class));
            }
            catch (BeanCreationException ex) {
               Throwable rootCause = ex.getMostSpecificCause();
               if (rootCause instanceof BeanCurrentlyInCreationException) {
                  BeanCreationException bce = (BeanCreationException) rootCause;
                  String bceBeanName = bce.getBeanName();
                  if (bceBeanName != null && this.beanFactory.isCurrentlyInCreation(bceBeanName)) {
                     if (logger.isDebugEnabled()) {
                        logger.debug("Skipping advisor '" + name +
                              "' with dependency on currently created bean: " + ex.getMessage());
                     }
                     // Ignore: indicates a reference back to the bean we're trying to advise.
                     // We want to find advisors other than the currently created bean itself.
                     continue;
                  }
               }
               throw ex;
            }
         }
      }
   }
   return advisors;
}
           

// BeanFactoryAspectJAdvisorsBuilder
public List<Advisor> buildAspectJAdvisors() {
   List<String> aspectNames = this.aspectBeanNames;

   if (aspectNames == null) {
      synchronized (this) {
         aspectNames = this.aspectBeanNames;
         if (aspectNames == null) {
            List<Advisor> advisors = new LinkedList<>();
            aspectNames = new LinkedList<>();
            // 擷取所有bean
            String[] beanNames = BeanFactoryUtils.beanNamesForTypeIncludingAncestors(
                  this.beanFactory, Object.class, true, false);
            for (String beanName : beanNames) {
               if (!isEligibleBean(beanName)) {
                  continue;
               }
               // We must be careful not to instantiate beans eagerly as in this case they
               // would be cached by the Spring container but would not have been weaved.
               // 擷取對應的bean類型
               Class<?> beanType = this.beanFactory.getType(beanName);
               if (beanType == null) {
                  continue;
               }
               // 判斷Bean是否添加@Aspect注解
               if (this.advisorFactory.isAspect(beanType)) {
                  aspectNames.add(beanName);
                  AspectMetadata amd = new AspectMetadata(beanType, beanName);
                  if (amd.getAjType().getPerClause().getKind() == PerClauseKind.SINGLETON) {
                     MetadataAwareAspectInstanceFactory factory =
                           new BeanFactoryAspectInstanceFactory(this.beanFactory, beanName);
                     // 擷取Aspect類所有方法的注解 
                     List<Advisor> classAdvisors = this.advisorFactory.getAdvisors(factory);
                     if (this.beanFactory.isSingleton(beanName)) {
                        this.advisorsCache.put(beanName, classAdvisors);
                     }
                     else {
                        this.aspectFactoryCache.put(beanName, factory);
                     }
                     advisors.addAll(classAdvisors);
                  }
                  else {
                     // Per target or per this.
                     if (this.beanFactory.isSingleton(beanName)) {
                        throw new IllegalArgumentException("Bean with name '" + beanName +
                              "' is a singleton, but aspect instantiation model is not singleton");
                     }
                     MetadataAwareAspectInstanceFactory factory =
                           new PrototypeAspectInstanceFactory(this.beanFactory, beanName);
                     this.aspectFactoryCache.put(beanName, factory);
                     advisors.addAll(this.advisorFactory.getAdvisors(factory));
                  }
               }
            }
            this.aspectBeanNames = aspectNames;
            return advisors;
         }
      }
   }

   if (aspectNames.isEmpty()) {
      return Collections.emptyList();
   }
   List<Advisor> advisors = new LinkedList<>();
   for (String aspectName : aspectNames) {
      List<Advisor> cachedAdvisors = this.advisorsCache.get(aspectName);
      if (cachedAdvisors != null) {
         advisors.addAll(cachedAdvisors);
      }
      else {
         MetadataAwareAspectInstanceFactory factory = this.aspectFactoryCache.get(aspectName);
         advisors.addAll(this.advisorFactory.getAdvisors(factory));
      }
   }
   return advisors;
}
           

// ReflectiveAspectJAdvisorFactory
public List<Advisor> getAdvisors(MetadataAwareAspectInstanceFactory aspectInstanceFactory) {
   Class<?> aspectClass = aspectInstanceFactory.getAspectMetadata().getAspectClass();
   String aspectName = aspectInstanceFactory.getAspectMetadata().getAspectName();
   validate(aspectClass);

   // We need to wrap the MetadataAwareAspectInstanceFactory with a decorator
   // so that it will only instantiate once.
   MetadataAwareAspectInstanceFactory lazySingletonAspectInstanceFactory =
         new LazySingletonAspectInstanceFactoryDecorator(aspectInstanceFactory);

   List<Advisor> advisors = new LinkedList<>();
   // 擷取aspect類上所有增強方法(Pointcut注解排除)
   for (Method method : getAdvisorMethods(aspectClass)) {
      // 擷取增強器
      Advisor advisor = getAdvisor(method, lazySingletonAspectInstanceFactory, advisors.size(), aspectName);
      if (advisor != null) {
         advisors.add(advisor);
      }
   }

   // If it's a per target aspect, emit the dummy instantiating aspect.
   if (!advisors.isEmpty() && lazySingletonAspectInstanceFactory.getAspectMetadata().isLazilyInstantiated()) {
      Advisor instantiationAdvisor = new SyntheticInstantiationAdvisor(lazySingletonAspectInstanceFactory);
      advisors.add(, instantiationAdvisor);
   }

   // Find introduction fields.
   // 查找引介增強 并添加至集合
   for (Field field : aspectClass.getDeclaredFields()) {
      Advisor advisor = getDeclareParentsAdvisor(field);
      if (advisor != null) {
         advisors.add(advisor);
      }
   }

   return advisors;
}
           

// ReflectiveAspectJAdvisorFactory
public Advisor getAdvisor(Method candidateAdviceMethod, MetadataAwareAspectInstanceFactory aspectInstanceFactory,
                    int declarationOrderInAspect, String aspectName) {

   validate(aspectInstanceFactory.getAspectMetadata().getAspectClass());
   // 擷取切入點表達式
   AspectJExpressionPointcut expressionPointcut = getPointcut(
         candidateAdviceMethod, aspectInstanceFactory.getAspectMetadata().getAspectClass());
   if (expressionPointcut == null) {
      return null;
   }

   // 初始化增強器
   return new InstantiationModelAwarePointcutAdvisorImpl(expressionPointcut, candidateAdviceMethod,
         this, aspectInstanceFactory, declarationOrderInAspect, aspectName);
}
           

// ReflectiveAspectJAdvisorFactory
private AspectJExpressionPointcut getPointcut(Method candidateAdviceMethod, Class<?> candidateAspectClass) {
   // 擷取方法上的注解(Before、Around、After、AfterReturning、AfterThrowing、Pointcut)
   AspectJAnnotation<?> aspectJAnnotation =
         AbstractAspectJAdvisorFactory.findAspectJAnnotationOnMethod(candidateAdviceMethod);
   if (aspectJAnnotation == null) {
      return null;
   }

   AspectJExpressionPointcut ajexp =
         new AspectJExpressionPointcut(candidateAspectClass, new String[], new Class<?>[]);
   // 設定切點表達式
   ajexp.setExpression(aspectJAnnotation.getPointcutExpression());
   if (this.beanFactory != null) {
      ajexp.setBeanFactory(this.beanFactory);
   }
   return ajexp;
}
           

下面開始看

InstantiationModelAwarePointcutAdvisorImpl

初始化流程

// InstantiationModelAwarePointcutAdvisorImpl
public InstantiationModelAwarePointcutAdvisorImpl(AspectJExpressionPointcut declaredPointcut,
      Method aspectJAdviceMethod, AspectJAdvisorFactory aspectJAdvisorFactory,
      MetadataAwareAspectInstanceFactory aspectInstanceFactory, int declarationOrder, String aspectName) {

   this.declaredPointcut = declaredPointcut;
   this.declaringClass = aspectJAdviceMethod.getDeclaringClass();
   this.methodName = aspectJAdviceMethod.getName();
   this.parameterTypes = aspectJAdviceMethod.getParameterTypes();
   this.aspectJAdviceMethod = aspectJAdviceMethod;
   this.aspectJAdvisorFactory = aspectJAdvisorFactory;
   this.aspectInstanceFactory = aspectInstanceFactory;
   this.declarationOrder = declarationOrder;
   this.aspectName = aspectName;
   // 判斷是否設定延遲執行個體化
   if (aspectInstanceFactory.getAspectMetadata().isLazilyInstantiated()) {
      // Static part of the pointcut is a lazy type.
      Pointcut preInstantiationPointcut = Pointcuts.union(
            aspectInstanceFactory.getAspectMetadata().getPerClausePointcut(), this.declaredPointcut);

      // Make it dynamic: must mutate from pre-instantiation to post-instantiation state.
      // If it's not a dynamic pointcut, it may be optimized out
      // by the Spring AOP infrastructure after the first evaluation.
      this.pointcut = new PerTargetInstantiationModelPointcut(
            this.declaredPointcut, preInstantiationPointcut, aspectInstanceFactory);
      this.lazy = true;
   }
   else {
      // A singleton aspect.
      this.pointcut = this.declaredPointcut;
      this.lazy = false;
      // 執行個體化增強器
      this.instantiatedAdvice = instantiateAdvice(this.declaredPointcut);
   }
}
           

// InstantiationModelAwarePointcutAdvisorImpl
private Advice instantiateAdvice(AspectJExpressionPointcut pointcut) {
   Advice advice = this.aspectJAdvisorFactory.getAdvice(this.aspectJAdviceMethod, pointcut,
         this.aspectInstanceFactory, this.declarationOrder, this.aspectName);
   return (advice != null ? advice : EMPTY_ADVICE);
}
           

// ReflectiveAspectJAdvisorFactory
public Advice getAdvice(Method candidateAdviceMethod, AspectJExpressionPointcut expressionPointcut,
                  MetadataAwareAspectInstanceFactory aspectInstanceFactory, int declarationOrder, String aspectName) {

   Class<?> candidateAspectClass = aspectInstanceFactory.getAspectMetadata().getAspectClass();
   validate(candidateAspectClass);

   AspectJAnnotation<?> aspectJAnnotation =
         AbstractAspectJAdvisorFactory.findAspectJAnnotationOnMethod(candidateAdviceMethod);
   if (aspectJAnnotation == null) {
      return null;
   }

   // If we get here, we know we have an AspectJ method.
   // Check that it's an AspectJ-annotated class
   if (!isAspect(candidateAspectClass)) {
      throw new AopConfigException("Advice must be declared inside an aspect type: " +
            "Offending method '" + candidateAdviceMethod + "' in class [" +
            candidateAspectClass.getName() + "]");
   }

   if (logger.isDebugEnabled()) {
      logger.debug("Found AspectJ method: " + candidateAdviceMethod);
   }

   AbstractAspectJAdvice springAdvice;

   // 根據注解類型選擇不同增強器
   switch (aspectJAnnotation.getAnnotationType()) {
      case AtBefore:
         springAdvice = new AspectJMethodBeforeAdvice(
               candidateAdviceMethod, expressionPointcut, aspectInstanceFactory);
         break;
      case AtAfter:
         springAdvice = new AspectJAfterAdvice(
               candidateAdviceMethod, expressionPointcut, aspectInstanceFactory);
         break;
      case AtAfterReturning:
         springAdvice = new AspectJAfterReturningAdvice(
               candidateAdviceMethod, expressionPointcut, aspectInstanceFactory);
         AfterReturning afterReturningAnnotation = (AfterReturning) aspectJAnnotation.getAnnotation();
         if (StringUtils.hasText(afterReturningAnnotation.returning())) {
            springAdvice.setReturningName(afterReturningAnnotation.returning());
         }
         break;
      case AtAfterThrowing:
         springAdvice = new AspectJAfterThrowingAdvice(
               candidateAdviceMethod, expressionPointcut, aspectInstanceFactory);
         AfterThrowing afterThrowingAnnotation = (AfterThrowing) aspectJAnnotation.getAnnotation();
         if (StringUtils.hasText(afterThrowingAnnotation.throwing())) {
            springAdvice.setThrowingName(afterThrowingAnnotation.throwing());
         }
         break;
      case AtAround:
         springAdvice = new AspectJAroundAdvice(
               candidateAdviceMethod, expressionPointcut, aspectInstanceFactory);
         break;
      case AtPointcut:
         if (logger.isDebugEnabled()) {
            logger.debug("Processing pointcut '" + candidateAdviceMethod.getName() + "'");
         }
         return null;
      default:
         throw new UnsupportedOperationException(
               "Unsupported advice type on method: " + candidateAdviceMethod);
   }

   // Now to configure the advice...
   springAdvice.setAspectName(aspectName);
   springAdvice.setDeclarationOrder(declarationOrder);
   String[] argNames = this.parameterNameDiscoverer.getParameterNames(candidateAdviceMethod);
   if (argNames != null) {
      springAdvice.setArgumentNamesFromStringArray(argNames);
   }
   springAdvice.calculateArgumentBindings();

   return springAdvice;
}
           

下面回到

AbstractAdvisorAutoProxyCreator.findEligibleAdvisors()

方法中，接着分析

findAdvisorsThatCanApply()

方法，确定哪些增強器可以應用在

bean

上

// AbstractAdvisorAutoProxyCreator
protected List<Advisor> findAdvisorsThatCanApply(
      List<Advisor> candidateAdvisors, Class<?> beanClass, String beanName) {

   ProxyCreationContext.setCurrentProxiedBeanName(beanName);
   try {
      // 擷取目前bean可用的增強器
      return AopUtils.findAdvisorsThatCanApply(candidateAdvisors, beanClass);
   }
   finally {
      ProxyCreationContext.setCurrentProxiedBeanName(null);
   }
}
           

// AopUtils
public static List<Advisor> findAdvisorsThatCanApply(List<Advisor> candidateAdvisors, Class<?> clazz) {
   if (candidateAdvisors.isEmpty()) {
      return candidateAdvisors;
   }
   List<Advisor> eligibleAdvisors = new LinkedList<>();
   // 首先處理引介增強是否可以應用在目前bean上
   for (Advisor candidate : candidateAdvisors) {
      if (candidate instanceof IntroductionAdvisor && canApply(candidate, clazz)) {
         eligibleAdvisors.add(candidate);
      }
   }
   boolean hasIntroductions = !eligibleAdvisors.isEmpty();
   for (Advisor candidate : candidateAdvisors) {
      if (candidate instanceof IntroductionAdvisor) {
         // 引介增強已處理
         continue;
      }
      // 判斷目前增強是否可以應用在目前bean上
      if (canApply(candidate, clazz, hasIntroductions)) {
         eligibleAdvisors.add(candidate);
      }
   }
   return eligibleAdvisors;
}
           

canApply

的重載方法最終都會調用到下列的

canApply(Advisor advisor, Class<?> targetClass, boolean hasIntroductions)

方法中

// AopUtils
public static boolean canApply(Advisor advisor, Class<?> targetClass, boolean hasIntroductions) {
   // 判斷引介增強是否比對
   if (advisor instanceof IntroductionAdvisor) {
      return ((IntroductionAdvisor) advisor).getClassFilter().matches(targetClass);
   }
   else if (advisor instanceof PointcutAdvisor) {
      PointcutAdvisor pca = (PointcutAdvisor) advisor;
      // 判斷是否可以應用在目前bean上
      return canApply(pca.getPointcut(), targetClass, hasIntroductions);
   }
   else {
      // It doesn't have a pointcut so we assume it applies.
      return true;
   }
}
           

// AopUtils
public static boolean canApply(Pointcut pc, Class<?> targetClass, boolean hasIntroductions) {
   Assert.notNull(pc, "Pointcut must not be null");
   if (!pc.getClassFilter().matches(targetClass)) {
      return false;
   }

   // 擷取方法比對器
   MethodMatcher methodMatcher = pc.getMethodMatcher();
   if (methodMatcher == MethodMatcher.TRUE) {
      // No need to iterate the methods if we're matching any method anyway...
      return true;
   }

   IntroductionAwareMethodMatcher introductionAwareMethodMatcher = null;
   if (methodMatcher instanceof IntroductionAwareMethodMatcher) {
      introductionAwareMethodMatcher = (IntroductionAwareMethodMatcher) methodMatcher;
   }

   Set<Class<?>> classes = new LinkedHashSet<>();
   if (!Proxy.isProxyClass(targetClass)) {
      classes.add(ClassUtils.getUserClass(targetClass));
   }
   classes.addAll(ClassUtils.getAllInterfacesForClassAsSet(targetClass));

   for (Class<?> clazz : classes) {
      Method[] methods = ReflectionUtils.getAllDeclaredMethods(clazz);
      for (Method method : methods) {
         if (introductionAwareMethodMatcher != null ?
               introductionAwareMethodMatcher.matches(method, targetClass, hasIntroductions) :
               methodMatcher.matches(method, targetClass)) {
            return true;
         }
      }
   }

   return false;
}
           

至此，這個配置解析流程完成。

參考資料

Spring源碼深度解析

https://blog.csdn.net/heroqiang/article/details/79037741