1. 注册AnnotationAwareAspectJAutoProxyCreator

@EnableAspectJAutoProxy --> @Import(AspectJAutoProxyRegistrar.class) --> 注册AnnotationAwareAspectJAutoProxyCreator后处理器

public abstract class AbstractAutoProxyCreator extends ProxyProcessorSupport implements SmartInstantiationAwareBeanPostProcessor, BeanFactoryAware {    ...    @Override    public Object postProcessAfterInitialization(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;    }    protected Object wrapIfNecessary(Object bean, String beanName, Object cacheKey) {        ...        // 非Advice、Pointcut、Advisor、AopInfrastructureBean类型，且无@Aspect注解        if (isInfrastructureClass(bean.getClass()) || shouldSkip(bean.getClass(), beanName)) {            this.advisedBeans.put(cacheKey, Boolean.FALSE);            return bean;        }        Object[] specificInterceptors = getAdvicesAndAdvisorsForBean(bean.getClass(), beanName, null);        if (specificInterceptors != DO_NOT_PROXY) {            ...            Object proxy = createProxy(bean.getClass(), beanName, specificInterceptors, new SingletonTargetSource(bean));            ...            return proxy;        }        ...    }    protected Object createProxy(Class
      beanClass, String beanName, Object[] specificInterceptors, TargetSource targetSource) {        ...        ProxyFactory proxyFactory = new ProxyFactory();        ...        Advisor[] advisors = buildAdvisors(beanName, specificInterceptors);        for (Advisor advisor : advisors) {            proxyFactory.addAdvisor(advisor);        }        ...        return proxyFactory.getProxy(getProxyClassLoader());    }    ...}

 

2. 扫描Advisor（Advice）

--> AbstractAdvisorAutoProxyCreator.getAdvicesAndAdvisorsForBean

--> AbstractAdvisorAutoProxyCreator.findEligibleAdvisors

public abstract class AbstractAdvisorAutoProxyCreator extends AbstractAutoProxyCreator {    ...    protected List
     
       findEligibleAdvisors(Class
       beanClass, String beanName) {        // 获取所有Advisor（Advice），排序如下：@Around -> @Before -> @After -> @AfterReturning -> @AfterThrowing -> @Around -> @Before -> ...        List
      
        candidateAdvisors = findCandidateAdvisors();         List
       
         eligibleAdvisors = findAdvisorsThatCanApply(candidateAdvisors, beanClass, beanName); // 适配Advisor（Advice）        extendAdvisors(eligibleAdvisors);        if (!eligibleAdvisors.isEmpty()) {            // 局部排序：@AfterThrowing -> @AfterThrowing -> @After -> @Around -> @Before -> @AfterThrowing -> ...            eligibleAdvisors = sortAdvisors(eligibleAdvisors);         }        return eligibleAdvisors;    }    ...}
       
      
     

--> findCandidateAdvisors

public class AnnotationAwareAspectJAutoProxyCreator extends AspectJAwareAdvisorAutoProxyCreator {    ...    private AspectJAdvisorFactory aspectJAdvisorFactory;    private BeanFactoryAspectJAdvisorsBuilder aspectJAdvisorsBuilder;    @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);    }    @Override    protected List
     
       findCandidateAdvisors() {        List
      
        advisors = super.findCandidateAdvisors();        advisors.addAll(this.aspectJAdvisorsBuilder.buildAspectJAdvisors());        return advisors;    }    ...}
      
     

--> BeanFactoryAspectJAdvisorsBuilderAdapter.buildAspectJAdvisors

public class BeanFactoryAspectJAdvisorsBuilder {    ...    private final AspectJAdvisorFactory advisorFactory; // ReflectiveAspectJAdvisorFactory    ...    public List
     
       buildAspectJAdvisors() {        List
      
        aspectNames = this.aspectBeanNames;        // 无缓存        if (aspectNames == null) {            synchronized (this) {                ...                if (aspectNames == null) {                    List
       
         advisors = new LinkedList
        
         ();                    ...                    String[] beanNames = BeanFactoryUtils.beanNamesForTypeIncludingAncestors(this.beanFactory, Object.class, true, false);                    for (String beanName : beanNames) {                        ...                        Class
          beanType = this.beanFactory.getType(beanName);                        ...                        if (this.advisorFactory.isAspect(beanType)) {                            ...                            if (amd.getAjType().getPerClause().getKind() == PerClauseKind.SINGLETON) { // 单实例                                MetadataAwareAspectInstanceFactory factory = new BeanFactoryAspectInstanceFactory(this.beanFactory, beanName);                                List
         
           classAdvisors = this.advisorFactory.getAdvisors(factory);                                ...                                advisors.addAll(classAdvisors);                            }                            else { // 多实例                                ...                                MetadataAwareAspectInstanceFactory factory = new PrototypeAspectInstanceFactory(this.beanFactory, beanName);                                ...                                advisors.addAll(this.advisorFactory.getAdvisors(factory));                            }                        }                    }                    ...                    return advisors;                }            }        }        // 有缓存        ...    }    ...}
         
        
       
      
     

--> ReflectiveAspectJAdvisorFactory.getAdvisors

public class ReflectiveAspectJAdvisorFactory extends AbstractAspectJAdvisorFactory implements Serializable {    ...    @Override    public List
     
       getAdvisors(MetadataAwareAspectInstanceFactory aspectInstanceFactory) {        Class
       aspectClass = aspectInstanceFactory.getAspectMetadata().getAspectClass();        ...        List
      
        advisors = new LinkedList
       
        ();        for (Method method : getAdvisorMethods(aspectClass)) { // 按方法上的注解排序：@Around -> @Before -> @After -> @AfterReturning -> @AfterThrowing            Advisor advisor = getAdvisor(method, lazySingletonAspectInstanceFactory, advisors.size(), aspectName);            if (advisor != null) {                advisors.add(advisor);            }        }        ...        return advisors;    }    @Override    public Advisor getAdvisor(Method candidateAdviceMethod, MetadataAwareAspectInstanceFactory aspectInstanceFactory, int declarationOrderInAspect, String aspectName) {        ...        AspectJExpressionPointcut expressionPointcut = getPointcut(candidateAdviceMethod, aspectInstanceFactory.getAspectMetadata().getAspectClass());        if (expressionPointcut == null) {            return null;        }        return new InstantiationModelAwarePointcutAdvisorImpl(expressionPointcut, candidateAdviceMethod, this, aspectInstanceFactory, declarationOrderInAspect, aspectName);    }    public Advice getAdvice(Method candidateAdviceMethod, AspectJExpressionPointcut expressionPointcut,            MetadataAwareAspectInstanceFactory aspectInstanceFactory, int declarationOrder, String aspectName) {        ...        AspectJAnnotation
         aspectJAnnotation = AbstractAspectJAdvisorFactory.findAspectJAnnotationOnMethod(candidateAdviceMethod);        AbstractAspectJAdvice springAdvice;        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);                ...                break;            case AtAfterThrowing:                springAdvice = new AspectJAfterThrowingAdvice(candidateAdviceMethod, expressionPointcut, aspectInstanceFactory);                ...                break;            case AtAround:                springAdvice = new AspectJAroundAdvice(candidateAdviceMethod, expressionPointcut, aspectInstanceFactory);                break;            case AtPointcut:                return null;            default:                ...        }        ...        return springAdvice;    }    ...}
       
      
     

--> new InstantiationModelAwarePointcutAdvisorImpl

class InstantiationModelAwarePointcutAdvisorImpl implements InstantiationModelAwarePointcutAdvisor, AspectJPrecedenceInformation, Serializable {    ...    public InstantiationModelAwarePointcutAdvisorImpl(AspectJExpressionPointcut declaredPointcut, Method aspectJAdviceMethod, AspectJAdvisorFactory aspectJAdvisorFactory,            MetadataAwareAspectInstanceFactory aspectInstanceFactory, int declarationOrder, String aspectName) {        ...        private Advice instantiatedAdvice;        ...        if (aspectInstanceFactory.getAspectMetadata().isLazilyInstantiated()) {            ...        }        else {            ...            this.instantiatedAdvice = instantiateAdvice(this.declaredPointcut);        }    }    private Advice instantiateAdvice(AspectJExpressionPointcut pcut) {        return this.aspectJAdvisorFactory.getAdvice(this.aspectJAdviceMethod, pcut, this.aspectInstanceFactory, this.declarationOrder, this.aspectName);    }    ...}

3. 创建代理

--> ProxyFactory.getProxy --> ProxyCreatorSupport.createAopProxy --> DefaultAopProxyFactory.createAopProxy

public class DefaultAopProxyFactory implements AopProxyFactory, Serializable {    @Override    public AopProxy createAopProxy(AdvisedSupport config) throws AopConfigException {        if (config.isOptimize() || config.isProxyTargetClass() || hasNoUserSuppliedProxyInterfaces(config)) {            ...            return new ObjenesisCglibAopProxy(config); // CGLIB代理        }        else {            return new JdkDynamicAopProxy(config); // JDK代理        }    }    ...}

--> JDK代理

final class JdkDynamicAopProxy implements AopProxy, InvocationHandler, Serializable {    ...    protected final AdvisedSupport advised; // ProxyFactory    ...    @Override    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {        ...        try {            ...            List

--> CGLIB代理

class CglibAopProxy implements AopProxy, Serializable {    ...    protected final AdvisedSupport advised; // ProxyFactory    ...    private Callback[] getCallbacks(Class
      rootClass) throws Exception {        ...        if (isStatic && isFrozen) {            Method[] methods = rootClass.getMethods();            ...            for (int x = 0; x < methods.length; x++) {                List

4. 创建拦截器链

--> ProxyFactory.getInterceptorsAndDynamicInterceptionAdvice

public class AdvisedSupport extends ProxyConfig implements Advised {    ...    AdvisorChainFactory advisorChainFactory = new DefaultAdvisorChainFactory();    ...    public List

public class DefaultAdvisorChainFactory implements AdvisorChainFactory, Serializable {    @Override    public List

public class DefaultAdvisorAdapterRegistry implements AdvisorAdapterRegistry, Serializable {    private final List
     
       adapters = new ArrayList
      
       (3);    public DefaultAdvisorAdapterRegistry() {        registerAdvisorAdapter(new MethodBeforeAdviceAdapter());        registerAdvisorAdapter(new AfterReturningAdviceAdapter());        registerAdvisorAdapter(new ThrowsAdviceAdapter());    }    ...    @Override    public MethodInterceptor[] getInterceptors(Advisor advisor) throws UnknownAdviceTypeException {        List
       
         interceptors = new ArrayList
        
         (3);        Advice advice = advisor.getAdvice();        if (advice instanceof MethodInterceptor) {            interceptors.add((MethodInterceptor) advice);        }        for (AdvisorAdapter adapter : this.adapters) {            if (adapter.supportsAdvice(advice)) {                interceptors.add(adapter.getInterceptor(advisor));            }        }        ...        return interceptors.toArray(new MethodInterceptor[interceptors.size()]);    }    @Override    public void registerAdvisorAdapter(AdvisorAdapter adapter) {        this.adapters.add(adapter);    }}
        
       
      
     

5. 调用拦截器链

--> ReflectiveMethodInvocation.proceed

public class ReflectiveMethodInvocation implements ProxyMethodInvocation, Cloneable {    ...    protected final List
      interceptorsAndDynamicMethodMatchers;    ...    @Override    public Object proceed() throws Throwable {        if (this.currentInterceptorIndex == this.interceptorsAndDynamicMethodMatchers.size() - 1) {            return invokeJoinpoint();        }        Object interceptorOrInterceptionAdvice = this.interceptorsAndDynamicMethodMatchers.get(++this.currentInterceptorIndex);        if (interceptorOrInterceptionAdvice instanceof InterceptorAndDynamicMethodMatcher) {            ...        }        else {            return ((MethodInterceptor) interceptorOrInterceptionAdvice).invoke(this);        }    }    protected Object invokeJoinpoint() throws Throwable {        return AopUtils.invokeJoinpointUsingReflection(this.target, this.method, this.arguments);    }    ...}

6. 五大通知（拦截器）

public class AspectJAroundAdvice extends AbstractAspectJAdvice implements MethodInterceptor, Serializable {    ...    @Override    public Object invoke(MethodInvocation mi) throws Throwable {        ...        ProxyMethodInvocation pmi = (ProxyMethodInvocation) mi;        ProceedingJoinPoint pjp = lazyGetProceedingJoinPoint(pmi);        JoinPointMatch jpm = getJoinPointMatch(pmi);        return invokeAdviceMethod(pjp, jpm, null, null);    }    ...}

public class MethodBeforeAdviceInterceptor implements MethodInterceptor, Serializable { // 由MethodBeforeAdviceAdapter创建    private MethodBeforeAdvice advice;    ...    @Override    public Object invoke(MethodInvocation mi) throws Throwable {        this.advice.before(mi.getMethod(), mi.getArguments(), mi.getThis() );        return mi.proceed();    }}

public class AspectJAfterAdvice extends AbstractAspectJAdvice implements MethodInterceptor, AfterAdvice, Serializable {    ...    @Override    public Object invoke(MethodInvocation mi) throws Throwable {        try {            return mi.proceed();        }        finally {            invokeAdviceMethod(getJoinPointMatch(), null, null);        }    }    ...}

public class AfterReturningAdviceInterceptor implements MethodInterceptor, AfterAdvice, Serializable { // 由AfterReturningAdviceAdapter创建    private final AfterReturningAdvice advice;    ...    @Override    public Object invoke(MethodInvocation mi) throws Throwable {        Object retVal = mi.proceed();        this.advice.afterReturning(retVal, mi.getMethod(), mi.getArguments(), mi.getThis());        return retVal;    }}

public class AspectJAfterThrowingAdvice extends AbstractAspectJAdvice implements MethodInterceptor, AfterAdvice, Serializable {    ...    @Override    public Object invoke(MethodInvocation mi) throws Throwable {        try {            return mi.proceed();        }        catch (Throwable ex) {            if (shouldInvokeOnThrowing(ex)) {                invokeAdviceMethod(getJoinPointMatch(), null, ex);            }            throw ex;        }    }    ...}

 --> 拦截器接口

public interface MethodInterceptor extends Interceptor {    Object invoke(MethodInvocation invocation) throws Throwable;}

public interface Interceptor extends Advice {}

public interface Advice { // 通知}