When was the autowiredannotationbeanpostprocessor instantiated?

AutowiredAnnotationBeanPostProcessor yes spring The cornerstone of automatic assembly , According to the foregoing 《 internalAutowiredAnnotationProcessor Where did it come from ？》, We already know that AutowiredAnnotationBeanPostProcessor When was it added BeanDefinition, In which step is it instantiated ？

Set the breakpoint at refresh() Methodical invokeBeanFactoryPostProcessors It's about

We can see invokeBeanFactoryPostProcessor Note on

/**
 * Instantiate and invoke all registered BeanFactoryPostProcessor beans,
 * respecting explicit order if given.
 * <p>Must be called before singleton instantiation.
 */

I have just passed CET-4 ： Instantiate and call all registered BeanFactoryPostProcessor, If the order is given , Come in order ~

Will there be instantiation here AutowiredAnnotationBeanPostProcessor Well ？

You can see , When the program runs ,beaDefinitionNames It contains org.springframework.context.annotation.internalAutowiredAnnotationProcessor Of

And the storage completes instantiation bean Of singletonObects There is no , in other words , up to now ,AutowiredAnnotationBeanPostProcessor Not yet instantiated

next step , perform invokeBeanFactoryPostProcessor, Look again singletonObects, You can see , It only includes ConfigurationClassPostProcessor、DefaultEventListenerFactory and EventListenerMethodProcessor Instantiate the object

What we care about AutowiredAnnotationBeanPostProcessor There is no instantiation , I think this is because it belongs to BeanPostProcessor This system , It doesn't belong to BeanFactoryPostProcessor System reasons

Carry on registerBeanPostProcessors(beanFactory), You can see it at the end ,AutowiredAnnotationBeanPostProcessor Instantiation is complete .

So you can locate ,AutowiredAnnotationBeanPostProcessor The instantiation of occurs in registerBeanPostProcessors(beanFactory) Inside

Follow in , The comments on the methods all look the same , The reality is totally different , about invokeBeanFactoryPostProcessor Is to instantiate and execute , And here is ： Instantiate and register all BeanPostProcessor, in other words , The call doesn't happen here .

/**
 * Instantiate and register all BeanPostProcessor beans,
 * respecting explicit order if given.
 * <p>Must be called before any instantiation of application beans.
 */
protected void registerBeanPostProcessors(ConfigurableListableBeanFactory beanFactory) {
   PostProcessorRegistrationDelegate.registerBeanPostProcessors(beanFactory, this);
}

Why? ？
My understanding is that BeanFactoryPostProcessor The object of enhancement is BeanFactory, I.e. container , They need to be executed before and after the container creation process , Because the user-defined object will be created soon , Which is execution finishBeanFactoryInitialization(beanFactory), It will be too late to delay , and BeanPostProcessor The object of enhancement is bean object , It should be around bean Before the creation of 、 In the create 、 Create and then execute , To enhance bean The effect of , So here is just instantiation and registration , It's not implemented .

The process of instantiation is also the same as that of ordinary bean object , It's also getBean/doGetBean/createBean/doCreate/createBeanInstance That set , This will be analyzed in a separate context .