Spring ApplicationContext Bean Register

2024-04-26

Spring의 Annotation 기반 Bean register 등록 원리

AnnotationConfigApplicationContext.class

	@Override
	public void register(Class<?>... componentClasses) {
		Assert.notEmpty(componentClasses, "At least one component class must be specified");
		StartupStep registerComponentClass = getApplicationStartup().start("spring.context.component-classes.register")
				.tag("classes", () -> Arrays.toString(componentClasses));
		this.reader.register(componentClasses);
		registerComponentClass.end();
	}

AnnotationConfigApplicationContext 클래스는 ApplicationContext의 구현체이다.

register를 사용해 빈 등록

AnnotatedBeanDefinitionReader.class

    private <T> void doRegisterBean(Class<T> beanClass, @Nullable String name,
			@Nullable Class<? extends Annotation>[] qualifiers, @Nullable Supplier<T> supplier,
			@Nullable BeanDefinitionCustomizer[] customizers) {

		AnnotatedGenericBeanDefinition abd = new AnnotatedGenericBeanDefinition(beanClass);
		if (this.conditionEvaluator.shouldSkip(abd.getMetadata())) {
			return;
		}

		abd.setAttribute(ConfigurationClassUtils.CANDIDATE_ATTRIBUTE, Boolean.TRUE);
		abd.setInstanceSupplier(supplier);
		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));
				}
			}
		}
		if (customizers != null) {
			for (BeanDefinitionCustomizer customizer : customizers) {
				customizer.customize(abd);
			}
		}

		BeanDefinitionHolder definitionHolder = new BeanDefinitionHolder(abd, beanName);
		definitionHolder = AnnotationConfigUtils.applyScopedProxyMode(scopeMetadata, definitionHolder, this.registry);
		BeanDefinitionReaderUtils.registerBeanDefinition(definitionHolder, this.registry);
	}

• AnnotatedGenericBeanDefinition : BeanDefinition(빈 설정 메타 정보)의 구현체, Bean의 속성, 생성자 등의 정보를 저장한다

  BeanDefinition은 @Bean 어노테이션에 의해 생성됨