BeanPostProcessor 和 BeanFactoryPostProcessor

BeanFactoryPostProcessor

对读取到的所有bean可以进行修改，在这之前已经拿到了所有的Bean定义，不管是xml还是注解

@Component
public class BeanFactoryPostProcessorImp implements BeanFactoryPostProcessor {
    
    @Override
    public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
    
        System.out.println("factory");
        System.out.println(beanFactory.getBeanDefinition("simple").getBeanClassName());
    }
}

BeanPostProcessor

initializeBean 在这个方法里执行后置处理器
在bean初始化前，初始化后可以进行处理

@Component
public class BeanPostProcessorImp implements BeanPostProcessor {
    
    @Override
    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
    
        System.out.println("初始化前");
        return bean;
    }

    @Override
    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
    
        System.out.println("初始化后");
        return bean;
    }
}

结语

BeanFactoryPostProcessor 顺序在前
BeanPostProcessor 顺序在后