Spring 源碼（三）註冊配置類 BeanDefinition 到容器

調用鏈路：

registerBeanDefinition:861, DefaultListableBeanFactory (org.springframework.beans.factory.support)
registerBeanDefinition:315, GenericApplicationContext (org.springframework.context.support)
registerBeanDefinition:149, BeanDefinitionReaderUtils (org.springframework.beans.factory.support)
registerBean:192, AnnotatedBeanDefinitionReader (org.springframework.context.annotation)
registerBean:142, AnnotatedBeanDefinitionReader (org.springframework.context.annotation)
register:131, AnnotatedBeanDefinitionReader (org.springframework.context.annotation)
register:160, AnnotationConfigApplicationContext (org.springframework.context.annotation)
<init>:83, AnnotationConfigApplicationContext (org.springframework.context.annotation)

源碼：

public void register(Class<?>... annotatedClasses) {
	for (Class<?> annotatedClass : annotatedClasses) {
		registerBean(annotatedClass);
	}
}

public void registerBean(Class<?> annotatedClass, String name, Class<? extends Annotation>... qualifiers) {
	AnnotatedGenericBeanDefinition abd = new AnnotatedGenericBeanDefinition(annotatedClass);
	if (this.conditionEvaluator.shouldSkip(abd.getMetadata())) {
		return;
	}

	ScopeMetadata scopeMetadata = this.scopeMetadataResolver.resolveScopeMetadata(abd);
	abd.setScope(scopeMetadata.getScopeName());
	String beanName = (name != null ? name : this.beanNameGenerator.generateBeanName(abd, this.registry));
	AnnotationConfigUtils.processCommonDefinitionAnnotations(abd);
	if (qualifiers != null) {
		for (Class<? extends Annotation> qualifier : qualifiers) {
			if (Primary.class == qualifier) {
				abd.setPrimary(true);
			}
			else if (Lazy.class == qualifier) {
				abd.setLazyInit(true);
			}
			else {
				abd.addQualifier(new AutowireCandidateQualifier(qualifier));
			}
		}
	}
	// 註冊配置類
	BeanDefinitionHolder definitionHolder = new BeanDefinitionHolder(abd, beanName);
	definitionHolder = AnnotationConfigUtils.applyScopedProxyMode(scopeMetadata, definitionHolder, this.registry);
	BeanDefinitionReaderUtils.registerBeanDefinition(definitionHolder, this.registry);
}

1. 先獲取全部的配置類
2. 循環調用registerBean方法
3. 經過 BeanDefinitionRegistry 將配置類的BeanDefinition 註冊到容器