Bean的代理对象是在其生命周期的哪一步完成的呢？

1.用了Transactional注解我们知道，执行这个方法的时候执行的是代理对象的方法，这个对象是在哪个地方被代理的呢。

**没有循环依赖的情况下是在bean初始化执行后置处理的时候，会调用AspectJAwareAdvisorAutoProxyCreator实现后置处理方法会去创建代理对象： wrappedBean = applyBeanPostProcessorsAfterInitialization(wrappedBean, beanName); **

protected Object initializeBean(String beanName, 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()) {
      //调用BeanPostProcessor 前置处理
      wrappedBean = applyBeanPostProcessorsBeforeInitialization(wrappedBean, beanName);
   }

   try {
       //调用自定义初始化方法
      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()) {
       //调用BeanPostProcessor 后置处理，也是在后置处理的时候会去调用
       //代理实现细节在AbstractAutoProxyCreator.postProcessAfterInitialization方法中
      wrappedBean = applyBeanPostProcessorsAfterInitialization(wrappedBean, beanName);
   }

   return wrappedBean;
}

进入到AbstractAutoProxyCreator.postProcessAfterInitialization瞅一下，发现后置处理的主要实现逻辑其实调用的是wrapIfNecssary

/**
 * Create a proxy with the configured interceptors if the bean is
 * identified as one to proxy by the subclass.
 * @see #getAdvicesAndAdvisorsForBean
 */
@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;
}

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;
}

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;
}

有循环依赖的时候，代理类就是通过获取三级缓存的ObjectFactory，然后getObject方法生成的代理类 ps：从三级缓存里面获取bean的代码就不贴了见之前的文章： spring的三级缓存源码跟踪

protected Object getEarlyBeanReference(String beanName, RootBeanDefinition mbd, Object bean) {
   Object exposedObject = bean;
   if (!mbd.isSynthetic() && hasInstantiationAwareBeanPostProcessors()) {
      for (SmartInstantiationAwareBeanPostProcessor bp : getBeanPostProcessorCache().smartInstantiationAware) {
          //会执行AbstractAutoProxyCreator的getEarlyBeanReference
         exposedObject = bp.getEarlyBeanReference(exposedObject, beanName);
      }
   }
   return exposedObject;
}

@Override
public Object getEarlyBeanReference(Object bean, String beanName) {
   Object cacheKey = getCacheKey(bean.getClass(), beanName);
   this.earlyProxyReferences.put(cacheKey, bean);
   //没有循环依赖的时候也是调用的这个方法
   return wrapIfNecessary(bean, beanName, cacheKey);
}