Spring类加载初始化Bean链路
1.spring类加载
AbstractApplicationContext.finishBeanFactoryInitialization(...);
beanFactory.preInstantiateSingletons();
DefaultListableBeanFactory.getBean(beanName);
AbstractBeanFactory.doGetBean();
AbstractAutowireCapableBeanFactory.createBean(....)
populateBean(beanName, mbd, instanceWrapper);
initializeBean(...)
//调用BeanPostProcessor.postProcessBeforeInitialization()方法
applyBeanPostProcessorsBeforeInitialization(wrappedBean, beanName);
//调用BeanPostProcessor.postProcessBeforeInitialization()方法
applyBeanPostProcessorsAfterInitialization(wrappedBean, beanName);
2.BeanPostProcessor有个实现类CommonAnnotationBeanPostProcessor,专门处理@PostConstruct @PreDestroy注解。
CommonAnnotationBeanPostProcessor的父类InitDestroyAnnotationBeanPostProcessor()
InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization()
InitDestroyAnnotationBeanPostProcessor.findLifecycleMetadata()
// 组装生命周期元数据
InitDestroyAnnotationBeanPostProcessor.buildLifecycleMetadata()
// 查找@PostConstruct注释的方法
InitDestroyAnnotationBeanPostProcessor.initAnnotationType
// 查找@PreDestroy注释方法
InitDestroyAnnotationBeanPostProcessor.destroyAnnotationType
// 反射调用
metadata.invokeInitMethods(bean, beanName);