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

AnnotationConfigApplicationContext 层级

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

1. 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));
}

2. 初始化自定义类：就是例子中的MainConfig

• register(annotatedClasses);

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

3. refresh 刷新容器：实例化bean，创建Bean代理都是在这一步