BeanDefinition
bean 对象的 class类型 是否是抽象类 构造方法和参数 其它属性等

BeanDefinitionRegistry
BeanFactory

DefaultListableBeanFactory

BeanFactory 接口 主要方法
getBean containBean getType getAliases 

BeanDefinitionRegistry 接口主要方法 
registerBeanDefinition removeBeanDefinition getBeanDefinition 

BeanFactory         内部使用
ApplicationContext  面向应用


BeanFactory 手工注册 和 从xml加载bean定义 实例



    public static void main(String[] args) throws Exception {
        
        DefaultListableBeanFactory beanRegistry = new DefaultListableBeanFactory();
        AbstractBeanDefinition definition = new RootBeanDefinition(Pet.class);
        MutablePropertyValues pvs = definition.getPropertyValues();
        System.out.println(pvs.size());
        System.out.println(pvs);
        pvs.addPropertyValue("id", "1");
        pvs.addPropertyValue("name", "tiger");

        System.out.println(pvs.size());
        System.out.println(pvs);
        
        beanRegistry.registerBeanDefinition("pet",definition);
        BeanFactory container = (BeanFactory)beanRegistry;
        Pet pet = (Pet)container.getBean("pet");
        System.out.println(pet);
        
        //
        loadFromXml();

    }
    
    private static void loadFromXml() {
        DefaultListableBeanFactory beanRegistry = new DefaultListableBeanFactory(); 
        XmlBeanDefinitionReader beanDefinitionReader = new XmlBeanDefinitionReader(beanRegistry);
        beanDefinitionReader.loadBeanDefinitions("classpath:simple.xml");
        BeanFactory container = (BeanFactory)beanRegistry;
        Pet pet = (Pet)container.getBean("pet");
        System.out.println(pet);
    }


完整代码
https://gitee.com/dyyx/springboothello/blob/master/src/main/java/spring/BeanFactoryTest.java




IoC容器负责管理 bean生命周期
扩展点
BeanFactoryPostProcessor 在容器实例化对象之前修改bean定义
org.springframework.core.Ordered

public interface BeanFactoryPostProcessor {
    void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException;
}

PropertyPlaceholderConfigurer
配置集中管理
使用配置值 替换 BeanDefinition 中的占位符 



BeanPostProcessor
BeanFactoryPostProcessor处理bean的定义
BeanPostProcessor处理实例化之后的bean 

public interface BeanPostProcessor {
    // 前置处理
    Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException;
    // 后置处理
    Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException;
}


ApplicationContextAware

ApplicationContextAwareProcessor implements BeanPostProcessor 
postProcessBeforeInitialization
invokeAwareInterfaces

    private void invokeAwareInterfaces(Object bean) {
        if (bean instanceof Aware) {
            if (bean instanceof EnvironmentAware) {
                ((EnvironmentAware) bean).setEnvironment(this.applicationContext.getEnvironment());
            }
            if (bean instanceof EmbeddedValueResolverAware) {
                ((EmbeddedValueResolverAware) bean).setEmbeddedValueResolver(this.embeddedValueResolver);
            }
            if (bean instanceof ResourceLoaderAware) {
                ((ResourceLoaderAware) bean).setResourceLoader(this.applicationContext);
            }
            if (bean instanceof ApplicationEventPublisherAware) {
                ((ApplicationEventPublisherAware) bean).setApplicationEventPublisher(this.applicationContext);
            }
            if (bean instanceof MessageSourceAware) {
                ((MessageSourceAware) bean).setMessageSource(this.applicationContext);
            }
            if (bean instanceof ApplicationContextAware) {
                ((ApplicationContextAware) bean).setApplicationContext(this.applicationContext);
            }
        }
    }



 spring bean 生命周期实例 
 spring bean生命周期及扩展点 
 BeanFactory和ApplicationContext的区别 
 Spring的BeanFactoryPostProcessor和BeanPostProcessor