spring小結---AOP源碼分析

ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();

// Prepare the bean factory for use in this context.
prepareBeanFactory(beanFactory);

try {
   // Allows post-processing of the bean factory in context subclasses.
   postProcessBeanFactory(beanFactory);

   // Invoke factory processors registered as beans in the context.
   invokeBeanFactoryPostProcessors(beanFactory);

   // Register bean processors that intercept bean creation.
   registerBeanPostProcessors(beanFactory);

   // Initialize message source for this context.
   initMessageSource();

   // Initialize event multicaster for this context.
   initApplicationEventMulticaster();

   // Initialize other special beans in specific context subclasses.
   onRefresh();

   // Check for listener beans and register them.
   registerListeners();

   // Instantiate all remaining (non-lazy-init) singletons.
   finishBeanFactoryInitialization(beanFactory);

   // Last step: publish corresponding event.
   finishRefresh();
}

 

介紹下

// Register bean processors that intercept bean creation.
registerBeanPostProcessors(beanFactory);

BeanPostProcessor主要是在bean實例化後，執行bean 的init, 設置屬性

註冊BeanPostProcessor之前，由於在beanfactory前面處理已註冊一些，如下beanfactory已有一些，

看一下

ConfigurationClassPostProcessor 的內部類

private static class ImportAwareBeanPostProcessor extends InstantiationAwareBeanPostProcessorAdapter {

   private final BeanFactory beanFactory;

@Override
public PropertyValues postProcessPropertyValues(
      PropertyValues pvs, PropertyDescriptor[] pds, Object bean, String beanName) {

   // Inject the BeanFactory before AutowiredAnnotationBeanPostProcessor's
   // postProcessPropertyValues method attempts to autowire other configuration beans.
   if (bean instanceof EnhancedConfiguration) {
      ((EnhancedConfiguration) bean).setBeanFactory(this.beanFactory);
   }
   return pvs;
}

@Override
public Object postProcessBeforeInitialization(Object bean, String beanName)  {
   if (bean instanceof ImportAware) {
      ImportRegistry ir = this.beanFactory.getBean(IMPORT_REGISTRY_BEAN_NAME, ImportRegistry.class);
      AnnotationMetadata importingClass = ir.getImportingClassFor(bean.getClass().getSuperclass().getName());
      if (importingClass != null) {
         ((ImportAware) bean).setImportMetadata(importingClass);
      }
   }
   return bean;
}

對於ImportAware，//作用是得到某類的註解，然後得到註解中的值，拿到值後，可以在代碼動態使用值

有些本質是利用importaware給某些屬性賦值

可參考@EnableRedisHttpSession利用importaware設置某個key的有效時長

 

 

註冊BeanPostProcessor，註冊需要用到的，

繼續往下面走，可以發現有7個beanPostProcessor

 

 

其中：BeanPostProcessorChecker,檢查bean實例化後是否經過postortprocessor處理，

 

對於處理Aop

//@Import(MyImportSelector.class)
@EnableAspectJAutoProxy
@EnableTransactionManagement
//@EnableLmqUtil
public class AppConfig {

打開@EnableAspectJAutoProxy，、

@Documented
@Import(AspectJAutoProxyRegistrar.class)
public @interface EnableAspectJAutoProxy {

打開AspectJAutoProxyRegistrar.class)

 * @see EnableAspectJAutoProxy
 */
class AspectJAutoProxyRegistrar implements ImportBeanDefinitionRegistrar {

   /**
    * Register, escalate, and configure the AspectJ auto proxy creator based on the value
    * of the @{@link EnableAspectJAutoProxy#proxyTargetClass()} attribute on the importing
    * {@code @Configuration} class.
    */
   @Override
   public void registerBeanDefinitions(
         AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
      //配置類加了EnableAspectJAutoProxy，就會多註冊一個後置處理器AnnotationAutoProxyCreator來處理AOP（默認是7個，加了這個便是8個），往bdmap加了一個AnnotationAutoProxyCreator
      AopConfigUtils.registerAspectJAnnotationAutoProxyCreatorIfNecessary(registry);

      AnnotationAttributes enableAspectJAutoProxy =

。。。。。。。。。。。

執行到registerBeanPostProcessors(beanFactory)最後一行，

 

再看下bdmap也會有（這裏，先註冊bd,再實例postprocessor）

發現beanpostprocessor實例對象是8個

因爲spring的registerBeanPostProcessors(beanFactory)過程中，會調用getbean（）（如果沒有，就實例化對象）,如下圖示，

所以執行後就會有上圖的arraylist的beanpostprocessor實例對象列表了，或許第二個截圖該放在後面。具體細節查看如下源碼。

String[] postProcessorNames = beanFactory.getBeanNamesForType(BeanPostProcessor.class, true, false);

   // Register BeanPostProcessorChecker that logs an info message when
   // a bean is created during BeanPostProcessor instantiation, i.e. when
   // a bean is not eligible for getting processed by all BeanPostProcessors.
   int beanProcessorTargetCount = beanFactory.getBeanPostProcessorCount() + 1 + postProcessorNames.length;
   beanFactory.addBeanPostProcessor(new BeanPostProcessorChecker(beanFactory, beanProcessorTargetCount));

   // Separate between BeanPostProcessors that implement PriorityOrdered,
   // Ordered, and the rest.
   List<BeanPostProcessor> priorityOrderedPostProcessors = new ArrayList<>();
   List<BeanPostProcessor> internalPostProcessors = new ArrayList<>();
   List<String> orderedPostProcessorNames = new ArrayList<>();
   List<String> nonOrderedPostProcessorNames = new ArrayList<>();
   for (String ppName : postProcessorNames) {
      if (beanFactory.isTypeMatch(ppName, PriorityOrdered.class)) {
         BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
         priorityOrderedPostProcessors.add(pp);
         if (pp instanceof MergedBeanDefinitionPostProcessor) {
            internalPostProcessors.add(pp);
         }
      }
      else if (beanFactory.isTypeMatch(ppName, Ordered.class)) {
         orderedPostProcessorNames.add(ppName);
      }
      else {
         nonOrderedPostProcessorNames.add(ppName);
      }
   }

   // First, register the BeanPostProcessors that implement PriorityOrdered.
   sortPostProcessors(priorityOrderedPostProcessors, beanFactory);
   registerBeanPostProcessors(beanFactory, priorityOrderedPostProcessors);

   // Next, register the BeanPostProcessors that implement Ordered.
   List<BeanPostProcessor> orderedPostProcessors = new ArrayList<>();
   for (String ppName : orderedPostProcessorNames) {
      BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
      orderedPostProcessors.add(pp);
      if (pp instanceof MergedBeanDefinitionPostProcessor) {
         internalPostProcessors.add(pp);
      }
   }
   sortPostProcessors(orderedPostProcessors, beanFactory);
   registerBeanPostProcessors(beanFactory, orderedPostProcessors);

   // Now, register all regular BeanPostProcessors.
   List<BeanPostProcessor> nonOrderedPostProcessors = new ArrayList<>();
   for (String ppName : nonOrderedPostProcessorNames) {
      BeanPostProcessor pp = beanFactory.getBean(ppName, BeanPostProcessor.class);
      nonOrderedPostProcessors.add(pp);
      if (pp instanceof MergedBeanDefinitionPostProcessor) {
         internalPostProcessors.add(pp);
      }
   }
   registerBeanPostProcessors(beanFactory, nonOrderedPostProcessors);

   // Finally, re-register all internal BeanPostProcessors.
   sortPostProcessors(internalPostProcessors, beanFactory);
   registerBeanPostProcessors(beanFactory, internalPostProcessors);

   // Re-register post-processor for detecting inner beans as ApplicationListeners,
   // moving it to the end of the processor chain (for picking up proxies etc).
   beanFactory.addBeanPostProcessor(new ApplicationListenerDetector(applicationContext));
}

 

具體看下AnnotationAutoProxyCreator,

public class AnnotationAwareAspectJAutoProxyCreator extends AspectJAwareAdvisorAutoProxyCreator {
    @Nullable
    private List<Pattern> includePatterns;
    @Nullable
    private AspectJAdvisorFactory aspectJAdvisorFactory;

..............................

查看AspectJAwareAdvisorAutoProxyCreator， 繼續看繼承，。。。。。。。。。。。。。。
AbstractAutoProxyCreator extends ProxyProcessorSupport implements SmartInstantiationAwareBeanPostProcessor, BeanFactoryAware {
..............

查看SmartInstantiationAwareBeanPostProcessor，，，，，繼續繼承
public interface InstantiationAwareBeanPostProcessor extends BeanPostProcessor {

。。。。。。。

可以看出AnnotationAwareAspectJAutoProxyCreator也是個BeanPostProcessor

public interface BeanPostProcessor {
    @Nullable
    default Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        return bean;
    }

    @Nullable
    default Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
        return bean;
    }

這裏就是流程：  object-實例-->AnnotationAwareAspectJAutoProxyCreator處理------》代理對象proxybean----》set property......

// Register bean processors that intercept bean creation.
registerBeanPostProcessors(beanFactory);

// Initialize message source for this context.
initMessageSource();

// Initialize event multicaster for this context.
initApplicationEventMulticaster();

// Initialize other special beans in specific context subclasses.
onRefresh();

// Check for listener beans and register them.
registerListeners();

// Instantiate all remaining (non-lazy-init) singletons.
finishBeanFactoryInitialization(beanFactory);

// Last step: publish corresponding event.
finishRefresh();

registerBeanPostProcessors(beanFactory);執行往後，查看onRefresh()，發現onRefresh()是空執行;

在這之前其實並沒有太多實例化，後面的纔是

所以着重查看finishBeanFactoryInitialization(beanFactory);

protected void finishBeanFactoryInitialization(ConfigurableListableBeanFactory beanFactory) {

............

    // Stop using the temporary ClassLoader for type matching.
   beanFactory.setTempClassLoader(null);

   // Allow for caching all bean definition metadata, not expecting further changes.
   beanFactory.freezeConfiguration();

   // Instantiate all remaining (non-lazy-init) singletons.
   beanFactory.preInstantiateSingletons();
}

進入 beanFactory.preInstantiateSingletons();

@Override
public void preInstantiateSingletons() throws BeansException {
   if (this.logger.isDebugEnabled()) {
      this.logger.debug("Pre-instantiating singletons in " + this);
   }

   // Iterate over a copy to allow for init methods which in turn register new bean definitions.
   // While this may not be part of the regular factory bootstrap, it does otherwise work fine.
   List<String> beanNames = new ArrayList<>(this.beanDefinitionNames);

   // Trigger initialization of all non-lazy singleton beans...
   for (String beanName : beanNames) {
      RootBeanDefinition bd = getMergedLocalBeanDefinition(beanName); //合併父類bd
      if (!bd.isAbstract() && bd.isSingleton() && !bd.isLazyInit()) {
         if (isFactoryBean(beanName)) { //是否是factorybean
            Object bean = getBean(FACTORY_BEAN_PREFIX + beanName);
            if (bean instanceof FactoryBean) {
               final FactoryBean<?> factory = (FactoryBean<?>) bean;
               boolean isEagerInit;
               if (System.getSecurityManager() != null && factory instanceof SmartFactoryBean) {
                  isEagerInit = AccessController.doPrivileged((PrivilegedAction<Boolean>)
                              ((SmartFactoryBean<?>) factory)::isEagerInit,
                        getAccessControlContext());
               }
               else {
                  isEagerInit = (factory instanceof SmartFactoryBean &&
                        ((SmartFactoryBean<?>) factory).isEagerInit());
               }
               if (isEagerInit) {
                  getBean(beanName);
               }
            }
         }
         else {
            getBean(beanName);
         }
      }
   }

   // Trigger post-initialization callback for all applicable beans...
   for (String beanName : beanNames) {
      Object singletonInstance = getSingleton(beanName);
      if (singletonInstance instanceof SmartInitializingSingleton) {
         final SmartInitializingSingleton smartSingleton = (SmartInitializingSingleton) singletonInstance;
         if (System.getSecurityManager() != null) {
            AccessController.doPrivileged((PrivilegedAction<Object>) () -> {
               smartSingleton.afterSingletonsInstantiated();
               return null;
            }, getAccessControlContext());
         }
         else {
            smartSingleton.afterSingletonsInstantiated();
         }
      }
   }
}

這裏先假設不是factorybean,便直接getbean()

進去getbean()，會進dogetbean()

/**
 * Return an instance, which may be shared or independent, of the specified bean.
 * @param name the name of the bean to retrieve
 * @param requiredType the required type of the bean to retrieve
 * @param args arguments to use when creating a bean instance using explicit arguments
 * (only applied when creating a new instance as opposed to retrieving an existing one)
 * @param typeCheckOnly whether the instance is obtained for a type check,
 * not for actual use
 * @return an instance of the bean
 * @throws BeansException if the bean could not be created
 */
@SuppressWarnings("unchecked")
protected <T> T doGetBean(final String name, @Nullable final Class<T> requiredType,
      @Nullable final Object[] args, boolean typeCheckOnly) throws BeansException {

   final String beanName = transformedBeanName(name);
   Object bean;

   // Eagerly check singleton cache for manually registered singletons.
   Object sharedInstance = getSingleton(beanName);
   if (sharedInstance != null && args == null) {
      if (logger.isDebugEnabled()) {
         if (isSingletonCurrentlyInCreation(beanName)) {
            logger.debug("Returning eagerly cached instance of singleton bean '" + beanName +
                  "' that is not fully initialized yet - a consequence of a circular reference");
         }
         else {
            logger.debug("Returning cached instance of singleton bean '" + beanName + "'");
         }
      }
      bean = getObjectForBeanInstance(sharedInstance, name, beanName, null);
   }

   else {
      // Fail if we're already creating this bean instance:
      // We're assumably within a circular reference.
      if (isPrototypeCurrentlyInCreation(beanName)) {
         throw new BeanCurrentlyInCreationException(beanName);
      }

      // Check if bean definition exists in this factory.
      BeanFactory parentBeanFactory = getParentBeanFactory();
      if (parentBeanFactory != null && !containsBeanDefinition(beanName)) {
         // Not found -> check parent.
         String nameToLookup = originalBeanName(name);
         if (parentBeanFactory instanceof AbstractBeanFactory) {
            return ((AbstractBeanFactory) parentBeanFactory).doGetBean(
                  nameToLookup, requiredType, args, typeCheckOnly);
         }
         else if (args != null) {
            // Delegation to parent with explicit args.
            return (T) parentBeanFactory.getBean(nameToLookup, args);
         }
         else {
            // No args -> delegate to standard getBean method.
            return parentBeanFactory.getBean(nameToLookup, requiredType);
         }
      }

      if (!typeCheckOnly) {
         markBeanAsCreated(beanName);
      }

      try {
         final RootBeanDefinition mbd = getMergedLocalBeanDefinition(beanName);
         checkMergedBeanDefinition(mbd, beanName, args);

         // Guarantee initialization of beans that the current bean depends on.
         String[] dependsOn = mbd.getDependsOn();
         if (dependsOn != null) {
            for (String dep : dependsOn) {
               if (isDependent(beanName, dep)) {
                  throw new BeanCreationException(mbd.getResourceDescription(), beanName,
                        "Circular depends-on relationship between '" + beanName + "' and '" + dep + "'");
               }
               registerDependentBean(dep, beanName);
               try {
                  getBean(dep);
               }
               catch (NoSuchBeanDefinitionException ex) {
                  throw new BeanCreationException(mbd.getResourceDescription(), beanName,
                        "'" + beanName + "' depends on missing bean '" + dep + "'", ex);
               }
            }
         }

         // Create bean instance.
         if (mbd.isSingleton()) {
            sharedInstance = getSingleton(beanName, () -> {
               try {
                  return createBean(beanName, mbd, args);
               }
               catch (BeansException ex) {
                  // Explicitly remove instance from singleton cache: It might have been put there
                  // eagerly by the creation process, to allow for circular reference resolution.
                  // Also remove any beans that received a temporary reference to the bean.
                  destroySingleton(beanName);
                  throw ex;
               }
            });
            bean = getObjectForBeanInstance(sharedInstance, name, beanName, mbd);
         }

         else if (mbd.isPrototype()) {
            // It's a prototype -> create a new instance.
            Object prototypeInstance = null;
            try {
               beforePrototypeCreation(beanName);
               prototypeInstance = createBean(beanName, mbd, args);
            }
            finally {
               afterPrototypeCreation(beanName);
            }
            bean = getObjectForBeanInstance(prototypeInstance, name, beanName, mbd);
         }

         else {
            String scopeName = mbd.getScope();
            final Scope scope = this.scopes.get(scopeName);
            if (scope == null) {
               throw new IllegalStateException("No Scope registered for scope name '" + scopeName + "'");
            }
            try {
               Object scopedInstance = scope.get(beanName, () -> {
                  beforePrototypeCreation(beanName);
                  try {
                     return createBean(beanName, mbd, args);
                  }
                  finally {
                     afterPrototypeCreation(beanName);
                  }
               });
               bean = getObjectForBeanInstance(scopedInstance, name, beanName, mbd);
            }
            catch (IllegalStateException ex) {
               throw new BeanCreationException(beanName,
                     "Scope '" + scopeName + "' is not active for the current thread; consider " +
                     "defining a scoped proxy for this bean if you intend to refer to it from a singleton",
                     ex);
            }
         }
      }
      catch (BeansException ex) {
         cleanupAfterBeanCreationFailure(beanName);
         throw ex;
      }
   }

   // Check if required type matches the type of the actual bean instance.
   if (requiredType != null && !requiredType.isInstance(bean)) {
      try {
         T convertedBean = getTypeConverter().convertIfNecessary(bean, requiredType);
         if (convertedBean == null) {
            throw new BeanNotOfRequiredTypeException(name, requiredType, bean.getClass());
         }
         return convertedBean;
      }
      catch (TypeMismatchException ex) {
         if (logger.isDebugEnabled()) {
            logger.debug("Failed to convert bean '" + name + "' to required type '" +
                  ClassUtils.getQualifiedName(requiredType) + "'", ex);
         }
         throw new BeanNotOfRequiredTypeException(name, requiredType, bean.getClass());
      }
   }
   return (T) bean;

}

細看以上代碼，以beanname爲“lmqhaha”爲例，首先先去獲取，如果有直接返回，沒有進入創建邏輯

由於lmqhaha需要新創建，需要進入以下流程

else {
   // Fail if we're already creating this bean instance:
   // We're assumably within a circular reference.
   if (isPrototypeCurrentlyInCreation(beanName)) {
      throw new BeanCurrentlyInCreationException(beanName);
   }

   // Check if bean definition exists in this factory.
   BeanFactory parentBeanFactory = getParentBeanFactory();
   if (parentBeanFactory != null && !containsBeanDefinition(beanName)) {
      // Not found -> check parent.
      String nameToLookup = originalBeanName(name);
      if (parentBeanFactory instanceof AbstractBeanFactory) {
         return ((AbstractBeanFactory) parentBeanFactory).doGetBean(
               nameToLookup, requiredType, args, typeCheckOnly);
      }
      else if (args != null) {
         // Delegation to parent with explicit args.
         return (T) parentBeanFactory.getBean(nameToLookup, args);
      }
      else {
         // No args -> delegate to standard getBean method.
         return parentBeanFactory.getBean(nameToLookup, requiredType);
      }
   }

   if (!typeCheckOnly) {
      markBeanAsCreated(beanName);
   }

   try {
      final RootBeanDefinition mbd = getMergedLocalBeanDefinition(beanName);
      checkMergedBeanDefinition(mbd, beanName, args);

      // Guarantee initialization of beans that the current bean depends on.
      String[] dependsOn = mbd.getDependsOn();
      if (dependsOn != null) {
         for (String dep : dependsOn) {
            if (isDependent(beanName, dep)) {
               throw new BeanCreationException(mbd.getResourceDescription(), beanName,
                     "Circular depends-on relationship between '" + beanName + "' and '" + dep + "'");
            }
            registerDependentBean(dep, beanName);
            try {
               getBean(dep);
            }
            catch (NoSuchBeanDefinitionException ex) {
               throw new BeanCreationException(mbd.getResourceDescription(), beanName,
                     "'" + beanName + "' depends on missing bean '" + dep + "'", ex);
            }
         }
      }

      // Create bean instance.
      if (mbd.isSingleton()) {
         sharedInstance = getSingleton(beanName, () -> {
            try {
               return createBean(beanName, mbd, args);
            }
            catch (BeansException ex) {
               // Explicitly remove instance from singleton cache: It might have been put there
               // eagerly by the creation process, to allow for circular reference resolution.
               // Also remove any beans that received a temporary reference to the bean.
               destroySingleton(beanName);
               throw ex;
            }
         });
         bean = getObjectForBeanInstance(sharedInstance, name, beanName, mbd);
      }

      else if (mbd.isPrototype()) {
         // It's a prototype -> create a new instance.
         Object prototypeInstance = null;
         try {
            beforePrototypeCreation(beanName);
            prototypeInstance = createBean(beanName, mbd, args);
         }
         finally {
            afterPrototypeCreation(beanName);
         }
         bean = getObjectForBeanInstance(prototypeInstance, name, beanName, mbd);
      }

      else {
         String scopeName = mbd.getScope();
         final Scope scope = this.scopes.get(scopeName);
         if (scope == null) {
            throw new IllegalStateException("No Scope registered for scope name '" + scopeName + "'");
         }
         try {
            Object scopedInstance = scope.get(beanName, () -> {
               beforePrototypeCreation(beanName);
               try {
                  return createBean(beanName, mbd, args);
               }
               finally {
                  afterPrototypeCreation(beanName);
               }
            });
            bean = getObjectForBeanInstance(scopedInstance, name, beanName, mbd);
         }
         catch (IllegalStateException ex) {
            throw new BeanCreationException(beanName,
                  "Scope '" + scopeName + "' is not active for the current thread; consider " +
                  "defining a scoped proxy for this bean if you intend to refer to it from a singleton",
                  ex);
         }
      }
   }

進入 sharedInstance = getSingleton(beanName, () -> {。。。。

 

getSingleton，目前爲空，畢竟還沒實例化

繼續往下走，經過

singletonObject = singletonFactory.getObject()，得到一個代理對象（由於之前@aspect作用於此類,爲了驗證aop,所以有個代理對象）

反過來細看下singletonObject = singletonFactory.getObject()，看下如何生成了cglib代理對象，也就是aop過程,

點進去singletonFactory.getObject()，由於上一級調用，匿名類，會進去

createBean(beanName, mbd, args)

接着進去

createBean(beanName, mbd, args)

protected Object createBean(String beanName, RootBeanDefinition mbd, @Nullable Object[] args)
      throws BeanCreationException {

   if (logger.isDebugEnabled()) {
      logger.debug("Creating instance of bean '" + beanName + "'");
   }
   RootBeanDefinition mbdToUse = mbd;

   // Make sure bean class is actually resolved at this point, and
   // clone the bean definition in case of a dynamically resolved Class
   // which cannot be stored in the shared merged bean definition.
   Class<?> resolvedClass = resolveBeanClass(mbd, beanName);
   if (resolvedClass != null && !mbd.hasBeanClass() && mbd.getBeanClassName() != null) {
      mbdToUse = new RootBeanDefinition(mbd);
      mbdToUse.setBeanClass(resolvedClass);
   }

   // Prepare method overrides.
   try {
      mbdToUse.prepareMethodOverrides();
   }
   catch (BeanDefinitionValidationException ex) {
      throw new BeanDefinitionStoreException(mbdToUse.getResourceDescription(),
            beanName, "Validation of method overrides failed", ex);
   }

   try {
      // Give BeanPostProcessors a chance to return a proxy instead of the target bean instance.
      Object bean = resolveBeforeInstantiation(beanName, mbdToUse);
      if (bean != null) {
         return bean;
      }
   }
   catch (Throwable ex) {
      throw new BeanCreationException(mbdToUse.getResourceDescription(), beanName,
            "BeanPostProcessor before instantiation of bean failed", ex);
   }

   try {
      Object beanInstance = doCreateBean(beanName, mbdToUse, args);
      if (logger.isDebugEnabled()) {
         logger.debug("Finished creating instance of bean '" + beanName + "'");
      }
      return beanInstance;

。。。。。

看下Object beanInstance = doCreateBean(beanName, mbdToUse, args);

進去

protected Object doCreateBean(final String beanName, final RootBeanDefinition mbd, final @Nullable Object[] args)
      throws BeanCreationException {

   // Instantiate the bean.
   BeanWrapper instanceWrapper = null;  //bean實例包裝類，可以通過getWrappedInstance()獲得實例對象
   if (mbd.isSingleton()) {
      instanceWrapper = this.factoryBeanInstanceCache.remove(beanName);
   }
   if (instanceWrapper == null) {
      instanceWrapper = createBeanInstance(beanName, mbd, args);
   }
   final Object bean = instanceWrapper.getWrappedInstance();
   Class<?> beanType = instanceWrapper.getWrappedClass();
   if (beanType != NullBean.class) {
      mbd.resolvedTargetType = 

此時如圖示，還是原生對象實例的lmqdao2, 還未變成代理對象，

後面過程是變換過程，

   // Allow post-processors to modify the merged bean definition.
   synchronized (mbd.postProcessingLock) {
      if (!mbd.postProcessed) {
         try {
            applyMergedBeanDefinitionPostProcessors(mbd, beanType, beanName);
         }
         catch (Throwable ex) {
            throw new BeanCreationException(mbd.getResourceDescription(), beanName,
                  "Post-processing of merged bean definition failed", ex);
         }
         mbd.postProcessed = true;
      }
   }

   // Eagerly cache singletons to be able to resolve circular references
   // even when triggered by lifecycle interfaces like BeanFactoryAware.
   boolean earlySingletonExposure = (mbd.isSingleton() && this.allowCircularReferences &&
         isSingletonCurrentlyInCreation(beanName));
   if (earlySingletonExposure) {
      if (logger.isDebugEnabled()) {
         logger.debug("Eagerly caching bean '" + beanName +
               "' to allow for resolving potential circular references");
      }
      addSingletonFactory(beanName, () -> getEarlyBeanReference(beanName, mbd, bean));
   }

   // Initialize the bean instance.
   Object exposedObject = bean;
   try {
      populateBean(beanName, mbd, instanceWrapper);
      exposedObject = initializeBean(beanName, exposedObject, mbd);
   }
   catch (Throwable ex) {
      if (ex instanceof BeanCreationException && beanName.equals(((BeanCreationException) ex).getBeanName())) {
         throw (BeanCreationException) ex;
      }
      else {
         throw new BeanCreationException(
               mbd.getResourceDescription(), beanName, "Initialization of bean failed", ex);
      }
   }

   if (earlySingletonExposure) {
      Object earlySingletonReference = getSingleton(beanName, false);
      if (earlySingletonReference != null) {
         if (exposedObject == bean) {
            exposedObject = earlySingletonReference;
         }
         else if (!this.allowRawInjectionDespiteWrapping && hasDependentBean(beanName)) {
            String[] dependentBeans = getDependentBeans(beanName);
            Set<String> actualDependentBeans = new LinkedHashSet<>(dependentBeans.length);
            for (String dependentBean : dependentBeans) {
               if (!removeSingletonIfCreatedForTypeCheckOnly(dependentBean)) {
                  actualDependentBeans.add(dependentBean);
               }
            }
            if (!actualDependentBeans.isEmpty()) {
               throw new BeanCurrentlyInCreationException(beanName,
                     "Bean with name '" + beanName + "' has been injected into other beans [" +
                     StringUtils.collectionToCommaDelimitedString(actualDependentBeans) +
                     "] in its raw version as part of a circular reference, but has eventually been " +
                     "wrapped. This means that said other beans do not use the final version of the " +
                     "bean. This is often the result of over-eager type matching - consider using " +
                     "'getBeanNamesOfType' with the 'allowEagerInit' flag turned off, for example.");
            }
         }
      }
   }

   // Register bean as disposable.
   try {
      registerDisposableBeanIfNecessary(beanName, bean, mbd);
   }
   catch (BeanDefinitionValidationException ex) {
      throw new BeanCreationException(
            mbd.getResourceDescription(), beanName, "Invalid destruction signature", ex);
   }

   return exposedObject;
}

上面那個過程纔是變換過程呢，

通過跟蹤，發現

try {
   populateBean(beanName, mbd, instanceWrapper);
   exposedObject = initializeBean(beanName, exposedObject, mbd);
}

執行後，就變爲代理對象了，看下initializeBean(beanName, exposedObject, mbd)

 * Initialize the given bean instance, applying factory callbacks
 * as well as init methods and bean post processors.
 * <p>Called from {@link #createBean} for traditionally defined beans,
 * and from {@link #initializeBean} for existing bean instances.
 * @param beanName the bean name in the factory (for debugging purposes)
 * @param bean the new bean instance we may need to initialize
 * @param mbd the bean definition that the bean was created with
 * (can also be {@code null}, if given an existing bean instance)
 * @return the initialized bean instance (potentially wrapped)
 * @see BeanNameAware
 * @see BeanClassLoaderAware
 * @see BeanFactoryAware
 * @see #applyBeanPostProcessorsBeforeInitialization
 * @see #invokeInitMethods
 * @see #applyBeanPostProcessorsAfterInitialization
 */
protected Object initializeBean(final String beanName, final Object bean, @Nullable RootBeanDefinition mbd) {
   if (System.getSecurityManager() != null) {
      AccessController.doPrivileged((PrivilegedAction<Object>) () -> {
         invokeAwareMethods(beanName, bean);
         return null;
      }, getAccessControlContext());
   }
   else {
      invokeAwareMethods(beanName, bean);
   }

   Object wrappedBean = bean;
   if (mbd == null || !mbd.isSynthetic()) {
      wrappedBean = applyBeanPostProcessorsBeforeInitialization(wrappedBean, beanName);
   }

   try {
      invokeInitMethods(beanName, wrappedBean, mbd);
   }
   catch (Throwable ex) {
      throw new BeanCreationException(
            (mbd != null ? mbd.getResourceDescription() : null),
            beanName, "Invocation of init method failed", ex);
   }
   if (mbd == null || !mbd.isSynthetic()) {
      wrappedBean = applyBeanPostProcessorsAfterInitialization(wrappedBean, beanName);
   }

   return wrappedBean;
}

斷點進入；執行剛進入bean還是原生對象，如下圖

if (mbd == null || !mbd.isSynthetic()) {
   wrappedBean = applyBeanPostProcessorsBeforeInitialization(wrappedBean, beanName); //執行完，還是原生對象
}

try {
   .............

所以變換在後面，也就是

  if (mbd == null || !mbd.isSynthetic()) {
      wrappedBean = applyBeanPostProcessorsAfterInitialization(wrappedBean, beanName);
   }

   return wrappedBean;
}

看下 applyBeanPostProcessorsAfterInitialization(wrappedBean, beanName);

進去上面的方法，

此時會有8個processor,依次處理原生對象bean,如下圖

那麼哪個processor處理使之變爲代理對象呢，如下圖示，

進入方法

Object current = beanProcessor.postProcessAfterInitialization(result, beanName);

進入

wrapIfNecessary(bean, beanName, cacheKey)

具體如下：

protected Object wrapIfNecessary(Object bean, String beanName, Object cacheKey) {
    if (StringUtils.hasLength(beanName) && this.targetSourcedBeans.contains(beanName)) {
        return bean;
    } else if (Boolean.FALSE.equals(this.advisedBeans.get(cacheKey))) {
        return bean;
    } else if (!this.isInfrastructureClass(bean.getClass()) && !this.shouldSkip(bean.getClass(), beanName)) {
//查看此bean實例的class是否在所有aspect切面的pointcut中，若有就加攔截器
        Object[] specificInterceptors = this.getAdvicesAndAdvisorsForBean(bean.getClass(), beanName, (TargetSource)null);
        if (specificInterceptors != DO_NOT_PROXY) {
            this.advisedBeans.put(cacheKey, Boolean.TRUE);
            Object proxy = this.createProxy(bean.getClass(), beanName, specificInterceptors, new SingletonTargetSource(bean));
            this.proxyTypes.put(cacheKey, proxy.getClass());
            return proxy;
        } else {
            this.advisedBeans.put(cacheKey, Boolean.FALSE);
            return bean;
        }
    } else {
        this.advisedBeans.put(cacheKey, Boolean.FALSE);
        return bean;
    }
}

進入createProxy

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 (this.shouldProxyTargetClass(beanClass, beanName)) {
            proxyFactory.setProxyTargetClass(true);
        } else {
            this.evaluateProxyInterfaces(beanClass, proxyFactory);
        }
    }

    Advisor[] advisors = this.buildAdvisors(beanName, specificInterceptors);
    proxyFactory.addAdvisors(advisors);
    proxyFactory.setTargetSource(targetSource);
    this.customizeProxyFactory(proxyFactory);
    proxyFactory.setFrozen(this.freezeProxy);
    if (this.advisorsPreFiltered()) {
        proxyFactory.setPreFiltered(true);
    }

    return proxyFactory.getProxy(this.getProxyClassLoader());
}

細看下advisors, 

然後advisors，targetsource都被放到proxyfactory中，

繼續

proxyFactory.getProxy(this.getProxyClassLoader())

進去

getProxy（）

繼續進入

接着進入後續

以上有3中代理，先簡單看下jdk的

ublic JdkDynamicAopProxy(AdvisedSupport config) throws AopConfigException {
    Assert.notNull(config, "AdvisedSupport must not be null");
    if (config.getAdvisors().length == 0 && config.getTargetSource() == AdvisedSupport.EMPTY_TARGET_SOURCE) {
        throw new AopConfigException("No advisors and no TargetSource specified");
    } else {
        this.advised = config;
    }
}

public Object getProxy() {
    return this.getProxy(ClassUtils.getDefaultClassLoader());
}

由於最上層是 getProxy()，看下jdk的getProxy()，也就是看下 this.getProxy(ClassUtils.getDefaultClassLoader());

public Object getProxy(@Nullable ClassLoader classLoader) {
    if (logger.isDebugEnabled()) {
        logger.debug("Creating JDK dynamic proxy: target source is " + this.advised.getTargetSource());
    }

    Class<?>[] proxiedInterfaces = AopProxyUtils.completeProxiedInterfaces(this.advised, true);
    this.findDefinedEqualsAndHashCodeMethods(proxiedInterfaces);
    return Proxy.newProxyInstance(classLoader, proxiedInterfaces, this);//jdk
}

這裏看下cglib

進入

然後就得到了cglib的代理對象了，具體省略