Spring源码分析（二）类扫描与Bean创建

1. 扫描包路径，将所有带有compont注解的类放到beanDefinitionMap 中

讲bean 都扫描到 beanDefinitionMap 中

private final Map beanDefinitionMap = new ConcurrentHashMap<>(256);

2. bean 实例化

方法调用链

AbtractApplicationContext.refresh()

--> AbtractApplicationContext.finishBeanFactoryInitialization()

--> DeFaultListAbleBeanFactory.preInstantiateSingletons()

--> AbtractBeanFactory.doGetBean()

-->AbstractBeanFactory.createBean()

-->AbstractAutowireCapableBeanFactory.createBean()

-->AbstractAutowireCapableBeanFactory.doCreateBean()

-->AbstractAutowireCapableBeanFactory.instantiateBean()

最终通过一个lambda表达式把创建出来的bean 放到单例池 singletonObjects 中去

org.springframework.beans.factory.support.DefaultSingletonBeanRegistry#getSingleton(java.lang.String, org.springframework.beans.factory.ObjectFactory)