ignoreDependencyInterface与registerResolvableDependency

AbstractApplicationContext#refresh方法有一个prepareBeanFactory

prepareBeanFactory方法

对beanFactory做准备工作

protected void prepareBeanFactory(ConfigurableListableBeanFactory beanFactory) {
		// Tell the internal bean factory to use the context's class loader etc.
		beanFactory.setBeanClassLoader(getClassLoader());
		beanFactory.setBeanExpressionResolver(new StandardBeanExpressionResolver(beanFactory.getBeanClassLoader()));
		beanFactory.addPropertyEditorRegistrar(new ResourceEditorRegistrar(this, getEnvironment()));

		// Configure the bean factory with context callbacks.
		beanFactory.addBeanPostProcessor(new ApplicationContextAwareProcessor(this));
		beanFactory.ignoreDependencyInterface(EnvironmentAware.class);
		beanFactory.ignoreDependencyInterface(EmbeddedValueResolverAware.class);
		beanFactory.ignoreDependencyInterface(ResourceLoaderAware.class);
		beanFactory.ignoreDependencyInterface(ApplicationEventPublisherAware.class);
		beanFactory.ignoreDependencyInterface(MessageSourceAware.class);
		beanFactory.ignoreDependencyInterface(ApplicationContextAware.class);

		// BeanFactory interface not registered as resolvable type in a plain factory.
		// MessageSource registered (and found for autowiring) as a bean.
		beanFactory.registerResolvableDependency(BeanFactory.class, beanFactory);
		beanFactory.registerResolvableDependency(ResourceLoader.class, this);
		beanFactory.registerResolvableDependency(ApplicationEventPublisher.class, this);
		beanFactory.registerResolvableDependency(ApplicationContext.class, this);

		// Register early post-processor for detecting inner beans as ApplicationListeners.
		beanFactory.addBeanPostProcessor(new ApplicationListenerDetector(this));

		// Detect a LoadTimeWeaver and prepare for weaving, if found.
		if (beanFactory.containsBean(LOAD_TIME_WEAVER_BEAN_NAME)) {
			beanFactory.addBeanPostProcessor(new LoadTimeWeaverAwareProcessor(beanFactory));
			// Set a temporary ClassLoader for type matching.
			beanFactory.setTempClassLoader(new ContextTypeMatchClassLoader(beanFactory.getBeanClassLoader()));
		}

		// Register default environment beans.
		if (!beanFactory.containsLocalBean(ENVIRONMENT_BEAN_NAME)) {
			beanFactory.registerSingleton(ENVIRONMENT_BEAN_NAME, getEnvironment());
		}
		if (!beanFactory.containsLocalBean(SYSTEM_PROPERTIES_BEAN_NAME)) {
			beanFactory.registerSingleton(SYSTEM_PROPERTIES_BEAN_NAME, getEnvironment().getSystemProperties());
		}
		if (!beanFactory.containsLocalBean(SYSTEM_ENVIRONMENT_BEAN_NAME)) {
			beanFactory.registerSingleton(SYSTEM_ENVIRONMENT_BEAN_NAME, getEnvironment().getSystemEnvironment());
		}
	}

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这个方法其实就是对beanfactory的一些属性设置，以及加入一些后续会用到的bean
这里看ignoreDependencyInterface的作用是什么
我了解到BeanFactory接口中有个方法叫ignoreDependencyInterface。从官方文档的“字面”来看，其作用指定自动装配(autowiring)的时候忽略的接口。还有一个很相似的方法叫ignoreDependencyType，同样其官方字面意思是指自动装配(autowiring)的时候忽略的类。
究竟这两个方法是不是我们的理解相同呢？真的可以让指定的接口和类在自动装配的时候被忽略？有没有注意不到的坑？

/**
* Ignore the given dependency interface for autowiring.
* 
This will typically be used by application contexts to register
* dependencies that are resolved in other ways, like BeanFactory through
* BeanFactoryAware or ApplicationContext through ApplicationContextAware.
* 
By default, only the BeanFactoryAware interface is ignored.
* For further types to ignore, invoke this method for each type.
* @param ifc the dependency interface to ignore
* @see org.springframework.beans.factory.BeanFactoryAware
* @see org.springframework.context.ApplicationContextAware
*/
void ignoreDependencyInterface(Class<?> ifc);

/**
* Ignore the given dependency type for autowiring:
* for example, String. Default is none.
* @param type the dependency type to ignore
*/
void ignoreDependencyType(Class<?> type);
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看上面的注释不是很明白，ignoreDependencyType和ignoreDependencyInterface，从方法名来看一个是忽略某些类的依赖，一个是忽略某些接口的依赖。什么意思呢？在Spring中我们经常使用的是面向接口的编程，也就是在自动注入中，如果发现接口或者类被ignoreDependency了，就不会自动注入了。比如说你不能自动注入BeanFactory和ApplicationContext，它们必须通过BeanFactoryAware和ApplicationContextAware来注入

beanFactory.ignoreDependencyInterface(EnvironmentAware.class);
1

这句代码表示的是

set方法内的类型，自动装配时会被忽略掉，想要注入必须通过bean继承EnvironmentAware接口。

registerResolvableDependency作用（功能上就像@Primary）
该方法在springIOC初始化的时候的使用，针对根据类型注入的情况
由于BeanFactory会有很多实现，如果我们在Spring中直接想注入BeanFactory类型的对象，不这么做的话会报错的。Spring通过这个registerResolvableDependency()方法很好的解决了这个问题，当你想要注入BeanFactory对象的时候，Spring在初始化时期就帮我们指定了要注入哪个对象
该方法的主要作用就是指定该类型接口，如果外部要注入该类型接口的对象，则会注入我们指定的对象，而不会去管其他接口实现类