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spring aop 中次要的主件次要分为以下几个局部：
- advisorCreator 继承 spring ioc 的扩大接口 beanPostProcessor，次要用来扫描获取 advisor；
- advisor spring aop 参谋的意思，封装了 spring aop 中的切点和告诉；
- advice spring aop 的切点，即 aop 的加强办法；
springBoot aop 的入口在 AopAutoConfiguration 这个类中，因为 springBoot 的主动拆卸中，是开启 aop 的，即 spring.aop.auto=true，同样默认配置 proxy-target-class 的至为 true，因而默认应用 cglib 来做动静代理。
@Configuration(proxyBeanMethods = false)
@ConditionalOnProperty(prefix = "spring.aop", name = "auto", havingValue = "true", matchIfMissing = true)
public class AopAutoConfiguration {@Configuration(proxyBeanMethods = false)
@ConditionalOnClass(Advice.class)
static class AspectJAutoProxyingConfiguration {@Configuration(proxyBeanMethods = false)
@EnableAspectJAutoProxy(proxyTargetClass = false)
@ConditionalOnProperty(prefix = "spring.aop", name = "proxy-target-class", havingValue = "false",
matchIfMissing = false)
static class JdkDynamicAutoProxyConfiguration { }
@Configuration(proxyBeanMethods = false)
@EnableAspectJAutoProxy(proxyTargetClass = true)
@ConditionalOnProperty(prefix = "spring.aop", name = "proxy-target-class", havingValue = "true",
matchIfMissing = true)
static class CglibAutoProxyConfiguration {}}
}跟进 @EnableAspectJAutoProxy 这个标签：
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Import(AspectJAutoProxyRegistrar.class)
public @interface EnableAspectJAutoProxy {
/**
* Indicate whether subclass-based (CGLIB) proxies are to be created as opposed
* to standard Java interface-based proxies. The default is {@code false}.
*/
boolean proxyTargetClass() default false;
/**
* Indicate that the proxy should be exposed by the AOP framework as a {@code ThreadLocal}
* for retrieval via the {@link org.springframework.aop.framework.AopContext} class.
* Off by default, i.e. no guarantees that {@code AopContext} access will work.
* @since 4.3.1
*/
boolean exposeProxy() default false;}
咱们能够看到往 ioc 容器中注入了一个 AspectJAutoProxyRegistrar 的类，跟进之, 咱们能够看到调用了 AopConfigUtil 的 registerAspectJAnnotationAutoProxyCreatorIfNecessary 办法，持续跟进咱们能够看到：往容器外面注入了一个 AnnotationAwareAspectJAutoProxyCreator 的 bean。
@Nullable
public static BeanDefinition registerAspectJAnnotationAutoProxyCreatorIfNecessary(BeanDefinitionRegistry registry, @Nullable Object source) {return registerOrEscalateApcAsRequired(AnnotationAwareAspectJAutoProxyCreator.class, registry, source);
}此外，AnnotationAwareAspectJAutoProxyCreator 的父类实现了 BeanFactoryAware 接口，在该办法中会调用其的 initBeanFactory 办法，如下：次要是实例化了 AnnotationAwareAspectJAutoProxyCreator 中的 aspectJAdvisorsBuilder 属性，该属性提供了后续的 advisor 的创立工作。
@Override
protected void initBeanFactory(ConfigurableListableBeanFactory beanFactory) {super.initBeanFactory(beanFactory);
if (this.aspectJAdvisorFactory == null) {this.aspectJAdvisorFactory = new ReflectiveAspectJAdvisorFactory(beanFactory);
}
this.aspectJAdvisorsBuilder =
new BeanFactoryAspectJAdvisorsBuilderAdapter(beanFactory, this.aspectJAdvisorFactory);
}因为 AnnotationAwareAspectJAutoProxyCreator 实现了 Spring 的后置处理器，而 PointcutAdvisor 创立是在其的 postProcessBeforeInstantiation 的办法中：
public Object postProcessBeforeInstantiation(Class<?> beanClass, String beanName) {Object cacheKey = getCacheKey(beanClass, beanName);
if (!StringUtils.hasLength(beanName) || !this.targetSourcedBeans.contains(beanName)) {if (this.advisedBeans.containsKey(cacheKey)) {return null;}
if (isInfrastructureClass(beanClass) || shouldSkip(beanClass, beanName)) {this.advisedBeans.put(cacheKey, Boolean.FALSE);
return null;
}
}
// Create proxy here if we have a custom TargetSource.
// Suppresses unnecessary default instantiation of the target bean:
// The TargetSource will handle target instances in a custom fashion.
TargetSource targetSource = getCustomTargetSource(beanClass, beanName);
if (targetSource != null) {if (StringUtils.hasLength(beanName)) {this.targetSourcedBeans.add(beanName);
}
Object[] specificInterceptors = getAdvicesAndAdvisorsForBean(beanClass, beanName, targetSource);
Object proxy = createProxy(beanClass, beanName, specificInterceptors, targetSource);
this.proxyTypes.put(cacheKey, proxy.getClass());
return proxy;
}
return null;
}这里的 isInfrastructureClass 办法次要是判断以后 bean 是否是 PointCut, Advice 等 aop 相干的类，如果是的话则该 bean 不能被代理。再来看下 shouldSkip 办法，改办法中蕴含了 adivor 的创立：
protected boolean shouldSkip(Class<?> beanClass, String beanName) {
// TODO: Consider optimization by caching the list of the aspect names
List<Advisor> candidateAdvisors = findCandidateAdvisors();
for (Advisor advisor : candidateAdvisors) {
if (advisor instanceof AspectJPointcutAdvisor &&
((AspectJPointcutAdvisor) advisor).getAspectName().equals(beanName)) {return true;}
}
return super.shouldSkip(beanClass, beanName);
}跟进 findCandidateAdvisors 办法，这里次要看 aspectJAdvisorsBuilder 的 buildAspectJAdvisors 办法
@Override
protected List<Advisor> findCandidateAdvisors() {
// Add all the Spring advisors found according to superclass rules.
List<Advisor> advisors = super.findCandidateAdvisors();
// Build Advisors for all AspectJ aspects in the bean factory.
if (this.aspectJAdvisorsBuilder != null) {advisors.addAll(this.aspectJAdvisorsBuilder.buildAspectJAdvisors());
}
return advisors;
}该办法中有个判断条件 this.advisorFactory.isAspect(beanType) 判断该 bean 是否打了 @Aspect 标签，再去做生成 advisor 的操作。这里会调用 advisorFactory 的 getAdvisors 办法。获取到 advisors 后并把之放入 advisorsCache 的缓存中。跟进 getAdvisors 办法：
public List<Advisor> buildAspectJAdvisors() {
List<String> aspectNames = this.aspectBeanNames;
if (aspectNames == null) {synchronized (this) {
aspectNames = this.aspectBeanNames;
if (aspectNames == null) {List<Advisor> advisors = new ArrayList<>();
aspectNames = new ArrayList<>();
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. Class<?> beanType = this.beanFactory.getType(beanName);
if (beanType == null) {continue;}
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);
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 ArrayList<>();
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;
}
这里的 getAdvisorMethods 办法获取了该类中除打了 @PointCut 的办法，而后依据 getAdvisor 办法获取 advisor，跟进之
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 ArrayList<>();
for (Method method : getAdvisorMethods(aspectClass)) {// Prior to Spring Framework 5.2.7, advisors.size() was supplied as the declarationOrderInAspect
// to getAdvisor(...) to represent the "current position" in the declared methods list. // However, since Java 7 the "current position" is not valid since the JDK no longer // returns declared methods in the order in which they are declared in the source code. // Thus, we now hard code the declarationOrderInAspect to 0 for all advice methods // 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 // AspectJPrecedenceComparator.getAspectDeclarationOrder(Advisor). Advisor advisor = getAdvisor(method, lazySingletonAspectInstanceFactory, 0, 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(0, instantiationAdvisor);
}
// Find introduction fields.
for (Field field : aspectClass.getDeclaredFields()) {Advisor advisor = getDeclareParentsAdvisor(field);
if (advisor != null) {advisors.add(advisor);
}
}
return advisors;
}
咱们能够看到返回了一个 InstantiationModelAwarePointcutAdvisorImpl 的 bean，而在该 bean 的结构器中会调用 aspectJAdvisorFactory 的 getAdvice 的办法从而获取 Advice：
public Advisor getAdvisor(Method candidateAdviceMethod, MetadataAwareAspectInstanceFactory aspectInstanceFactory,
int declarationOrderInAspect, String aspectName) {validate(aspectInstanceFactory.getAspectMetadata().getAspectClass());
AspectJExpressionPointcut expressionPointcut = getPointcut(candidateAdviceMethod, aspectInstanceFactory.getAspectMetadata().getAspectClass());
if (expressionPointcut == null) {return null;}
return new InstantiationModelAwarePointcutAdvisorImpl(expressionPointcut, candidateAdviceMethod,
this, aspectInstanceFactory, declarationOrderInAspect, aspectName);
}
依据办法上的标签类型来确定告诉的类型。
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;
switch (aspectJAnnotation.getAnnotationType()) {
case AtPointcut:
if (logger.isDebugEnabled()) {logger.debug("Processing pointcut'" + candidateAdviceMethod.getName() + "'");
}
return null;
case AtAround:
springAdvice = new AspectJAroundAdvice(candidateAdviceMethod, expressionPointcut, aspectInstanceFactory);
break;
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;
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;
}
生成参谋和告诉之后，下一步就是创立代理类了, springBoot 默认采纳 cglib 来创立动静代理，代理类的创立在 spring 后置处理器的 postProcessAfterInitialization 中实现：
@Override
public Object postProcessAfterInitialization(@Nullable Object bean, String beanName) {if (bean != null) {Object cacheKey = getCacheKey(bean.getClass(), beanName);
if (this.earlyProxyReferences.remove(cacheKey) != bean) {return wrapIfNecessary(bean, beanName, cacheKey);
}
}
return bean;
}
跟进 wrapIfNecessary 办法，重点看 getAdvicesAndAdvisorsForBean 办法，该办法是获取 bean 的告诉和加强办法，如果一个都没找到，间接返回 bean, 只有找到，就创立代理对象。
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;}
if (isInfrastructureClass(bean.getClass()) || shouldSkip(bean.getClass(), beanName)) {this.advisedBeans.put(cacheKey, Boolean.FALSE);
return bean;
}
// Create proxy if we have advice.
Object[] specificInterceptors = getAdvicesAndAdvisorsForBean(bean.getClass(), beanName, null);
if (specificInterceptors != DO_NOT_PROXY) {this.advisedBeans.put(cacheKey, Boolean.TRUE);
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;
}
跟进 getAdvicesAndAdvisorsForBean 办法，其中要害办法为 findEligibleAdvisors，这里的 findCandidateAdvisors 能够从缓存中失去之前创立的 advisor。而 findAdvisorsThatCanApply 办法则是为 bean 寻找相匹配的告诉和加强办法，跟进之。
protected List<Advisor> findEligibleAdvisors(Class<?> beanClass, String beanName) {List<Advisor> candidateAdvisors = findCandidateAdvisors();
List<Advisor> eligibleAdvisors = findAdvisorsThatCanApply(candidateAdvisors, beanClass, beanName);
extendAdvisors(eligibleAdvisors);
if (!eligibleAdvisors.isEmpty()) {eligibleAdvisors = sortAdvisors(eligibleAdvisors);
}
return eligibleAdvisors;
}
持续跟进会进入 AopUtil 的 findAdvisorsThatCanApply 办法：
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;}
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;
}
该办法中会调用 canApply 办法去判断 advisor 和以后的 bean 是否匹配：
public static boolean canApply(Advisor advisor, Class<?> targetClass, boolean hasIntroductions) {if (advisor instanceof IntroductionAdvisor) {return ((IntroductionAdvisor) advisor).getClassFilter().matches(targetClass);
}
else if (advisor instanceof PointcutAdvisor) {PointcutAdvisor pca = (PointcutAdvisor) advisor;
return canApply(pca.getPointcut(), targetClass, hasIntroductions);
}
else {
// It doesn't have a pointcut so we assume it applies.
return true;
}
}
因为咱们之前创立的 advvisor 为 InstantiationModelAwarePointcutAdvisorImpl，该类实现了 PointcutAdvisor 接口，这里走 canApply 办法：
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;}
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;
}具体的匹配比较复杂，在 SignaturePattern 中的 matchesExactlyMethod 中对代理的办法做了匹配。
private FuzzyBoolean matchesExactlyMethod(JoinPointSignature aMethod, World world, boolean subjectMatch) {if (parametersCannotMatch(aMethod)) {// System.err.println("Parameter types pattern" + parameterTypes + "pcount:" + aMethod.getParameterTypes().length);
return FuzzyBoolean.NO;
}
// OPTIMIZE only for exact match do the pattern match now? Otherwise defer it until other fast checks complete?
if (!name.matches(aMethod.getName())) {return FuzzyBoolean.NO;}
// Check the throws pattern
if (subjectMatch && !throwsPattern.matches(aMethod.getExceptions(), world)) {return FuzzyBoolean.NO;}
// '*' trivially matches everything, no need to check further
if (!declaringType.isStar()) {if (!declaringType.matchesStatically(aMethod.getDeclaringType().resolve(world))) {return FuzzyBoolean.MAYBE;}
}
// '*' would match any return value
if (!returnType.isStar()) {boolean b = returnType.isBangVoid();
if (b) {String s = aMethod.getReturnType().getSignature();
if (s.length() == 1 && s.charAt(0) == 'V') {
// it is void, so not a match
return FuzzyBoolean.NO;
}
} else {if (returnType.isVoid()) {String s = aMethod.getReturnType().getSignature();
if (s.length() != 1 || s.charAt(0) != 'V') {
// it is not void, so not a match
return FuzzyBoolean.NO;
}
} else {if (!returnType.matchesStatically(aMethod.getReturnType().resolve(world))) {
// looking bad, but there might be parameterization to consider...
if (!returnType.matchesStatically(aMethod.getGenericReturnType().resolve(world))) {
// ok, it's bad.
return FuzzyBoolean.MAYBE;
}
}
}
}
}
// The most simple case: pattern is (..) will match anything
if (parameterTypes.size() == 1 && parameterTypes.get(0).isEllipsis()) {return FuzzyBoolean.YES;}
if (!parameterTypes.canMatchSignatureWithNParameters(aMethod.getParameterTypes().length)) {return FuzzyBoolean.NO;}
// OPTIMIZE both resolution of these types and their annotations should be deferred - just pass down a world and do it lower
// down
// ResolvedType[] resolvedParameters = world.resolve(aMethod.getParameterTypes());
ResolvableTypeList rtl = new ResolvableTypeList(world, aMethod.getParameterTypes());
// Only fetch the parameter annotations if the pointcut is going to be matching on them
ResolvedType[][] parameterAnnotationTypes = null;
if (isMatchingParameterAnnotations()) {parameterAnnotationTypes = aMethod.getParameterAnnotationTypes();
if (parameterAnnotationTypes != null && parameterAnnotationTypes.length == 0) {parameterAnnotationTypes = null;}
}
if (!parameterTypes.matches(rtl, TypePattern.STATIC, parameterAnnotationTypes).alwaysTrue()) {
// It could still be a match based on the generic sig parameter types of a parameterized type
if (!parameterTypes.matches(new ResolvableTypeList(world, aMethod.getGenericParameterTypes()), TypePattern.STATIC,
parameterAnnotationTypes).alwaysTrue()) {
return FuzzyBoolean.MAYBE;
// It could STILL be a match based on the erasure of the parameter types??
// to be determined via test cases...
}
}
// check that varargs specifications match
if (!matchesVarArgs(aMethod, world)) {return FuzzyBoolean.MAYBE;}
// passed all the guards..
return FuzzyBoolean.YES;
}
获取到 aop 的拦挡办法之后调用 createProxy 办法创立代理类：
protected Object createProxy(Class<?> beanClass, @Nullable String beanName,
@Nullable Object[] specificInterceptors, TargetSource targetSource) {if (this.beanFactory instanceof ConfigurableListableBeanFactory) {AutoProxyUtils.exposeTargetClass((ConfigurableListableBeanFactory) this.beanFactory, beanName, beanClass);
}
ProxyFactory proxyFactory = new ProxyFactory();
proxyFactory.copyFrom(this);
if (!proxyFactory.isProxyTargetClass()) {if (shouldProxyTargetClass(beanClass, beanName)) {proxyFactory.setProxyTargetClass(true);
}
else {evaluateProxyInterfaces(beanClass, proxyFactory);
}
}
Advisor[] advisors = buildAdvisors(beanName, specificInterceptors);
proxyFactory.addAdvisors(advisors);
proxyFactory.setTargetSource(targetSource);
customizeProxyFactory(proxyFactory);
proxyFactory.setFrozen(this.freezeProxy);
if (advisorsPreFiltered()) {proxyFactory.setPreFiltered(true);
}
return proxyFactory.getProxy(getProxyClassLoader());
}
持续跟进 getProxy 会进入到 DefaultProsyFactory 的 createAopProxy 办法，这里能够看到应用 jdk 动静代理还是应用 cglib 作为动静代理的判断条件
public AopProxy createAopProxy(AdvisedSupport config) throws AopConfigException {if (config.isOptimize() || config.isProxyTargetClass() || hasNoUserSuppliedProxyInterfaces(config)) {Class<?> targetClass = config.getTargetClass();
if (targetClass == null) {
throw new AopConfigException("TargetSource cannot determine target class:" +
"Either an interface or a target is required for proxy creation.");
}
if (targetClass.isInterface() || Proxy.isProxyClass(targetClass)) {return new JdkDynamicAopProxy(config);
}
return new ObjenesisCglibAopProxy(config);
}
else {return new JdkDynamicAopProxy(config);
}
}
动静代理的调用，这里以 cglib 做示例：当执行被代理对象的业务办法时，会执行 CglibAopProxy 的 intercept 办法：
Object oldProxy = null;
boolean setProxyContext = false;
Object target = null;
TargetSource targetSource = this.advised.getTargetSource();
try {if (this.advised.exposeProxy) {
// Make invocation available if necessary.
oldProxy = AopContext.setCurrentProxy(proxy);
setProxyContext = true;
}
// Get as late as possible to minimize the time we "own" the target, in case it comes from a pool...
target = targetSource.getTarget();
Class<?> targetClass = (target != null ? target.getClass() : null);
List<Object> chain = this.advised.getInterceptorsAndDynamicInterceptionAdvice(method, targetClass);
Object retVal;
// Check whether we only have one InvokerInterceptor: that is,
// no real advice, but just reflective invocation of the target.
if (chain.isEmpty() && Modifier.isPublic(method.getModifiers())) {
// We can skip creating a MethodInvocation: just invoke the target directly.
// Note that the final invoker must be an InvokerInterceptor, so we know
// it does nothing but a reflective operation on the target, and no hot
// swapping or fancy proxying.
Object[] argsToUse = AopProxyUtils.adaptArgumentsIfNecessary(method, args);
retVal = methodProxy.invoke(target, argsToUse);
}
else {
// We need to create a method invocation...
retVal = new CglibMethodInvocation(proxy, target, method, args, targetClass, chain, methodProxy).proceed();}
retVal = processReturnType(proxy, target, method, retVal);
return retVal;
}
finally {if (target != null && !targetSource.isStatic()) {targetSource.releaseTarget(target);
}
if (setProxyContext) {
// Restore old proxy.
AopContext.setCurrentProxy(oldProxy);
}
}
}
这里的 getInterceptorsAndDynamicInterceptionAdvice 办法通过 Advice 获取到对应测加强办法，如果缓存中没有 CglibMethodInvocation 的对象的话，就 new 了一个并执行他的 proceed 办法。跟进进入 ReflectiveMethodInvocation 的 proceed 办法。
public Object proceed() throws Throwable {
// We start with an index of -1 and increment early.
if (this.currentInterceptorIndex == this.interceptorsAndDynamicMethodMatchers.size() - 1) {return invokeJoinpoint();
}
Object interceptorOrInterceptionAdvice =
this.interceptorsAndDynamicMethodMatchers.get(++this.currentInterceptorIndex);
if (interceptorOrInterceptionAdvice instanceof InterceptorAndDynamicMethodMatcher) {
// Evaluate dynamic method matcher here: static part will already have
// been evaluated and found to match.
InterceptorAndDynamicMethodMatcher dm =
(InterceptorAndDynamicMethodMatcher) interceptorOrInterceptionAdvice;
Class<?> targetClass = (this.targetClass != null ? this.targetClass : this.method.getDeclaringClass());
if (dm.methodMatcher.matches(this.method, targetClass, this.arguments)) {return dm.interceptor.invoke(this);
}
else {
// Dynamic matching failed.
// Skip this interceptor and invoke the next in the chain.
return proceed();}
}
else {
// It's an interceptor, so we just invoke it: The pointcut will have
// been evaluated statically before this object was constructed.
return ((MethodInterceptor) interceptorOrInterceptionAdvice).invoke(this);
}
}
这里的 currentInterceptorIndex 记录加强办法的索引，从 - 1 开始，没执行一个加强办法该值加 1，加强办法执行之后持续调用这个 proceed 办法，直到最初一个加强办法被执行，之后执行被代理办法。然而对于 After 告诉类型的加强办法并没有马上执行，而是写在了 finally 块中：
正文完