spring容器(一)（|spring容器(一)：容器创建起点） spring容器(一)：容器创建起点

1. 起点

public class AopDemo {static public void main(String[] args) { AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(MainConfig.class); context.getBean(MathCalculator.class).div(4, 2); } }

2. 新建，初始化容器

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AnnotationConfigApplicationContext 层级

public AnnotationConfigApplicationContext(Class... annotatedClasses) { this(); register(annotatedClasses); refresh(); }

this(): 创建容器，并初始化beanMap

创建BeanFactory
AnnotationConfigApplicationContext 继承 GenericApplicationContext，在调用AnnotationConfigApplicationContext的构造函数时，会先调用父类的构造函数创建BeanFactory：

public GenericApplicationContext() { this.beanFactory = new DefaultListableBeanFactory(); }

初始化beanMap
添加内部管理beans

org.springframework.context.annotation.internalConfigurationAnnotationProcessor, org.springframework.context.annotation.internalAutowiredAnnotationProcessor, org.springframework.context.annotation.internalRequiredAnnotationProcessor, org.springframework.context.annotation.internalCommonAnnotationProcessor, org.springframework.context.annotation.internalPersistenceAnnotationProcessor, org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor, org.springframework.context.event.internalEventListenerProcessor, org.springframework.context.event.internalEventListenerFactory

if (!registry.containsBeanDefinition(CONFIGURATION_ANNOTATION_PROCESSOR_BEAN_NAME)) { RootBeanDefinition def = new RootBeanDefinition(ConfigurationClassPostProcessor.class); def.setSource(source); beanDefs.add(registerPostProcessor(registry, def, CONFIGURATION_ANNOTATION_PROCESSOR_BEAN_NAME)); }

初始化自定义类：就是例子中的MainConfig

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