BeanFactoryPostProcessor与BeanPostProcessor区别

Spring IoC容器允许BeanFactoryPostProcessor在容器实例化任何bean之前读取bean的定义(BeanDefinition)，并可以修改它（参见Spring的
PropertyResourceConfigurer源码）。同时可以定义多个BeanFactoryPostProcessor，通过设置'order'属性来确定各个BeanFactoryPostProcessor执行顺序。'order'值越小优先级越高。

注册一个BeanFactoryPostProcessor实例需要定义一个Java类来实现BeanFactoryPostProcessor接口，并重写该接口的postProcessorBeanFactory方法。通过beanFactory可以获取bean的定义信息，并可以修改bean的定义信息。这点是和BeanPostProcessor最大区别

public interface BeanFactoryPostProcessor {

   /**
    * Modify the application context's internal bean factory after its standard
    * initialization. All bean definitions will have been loaded, but no beans
    * will have been instantiated yet. This allows for overriding or adding
    * properties even to eager-initializing beans.
    * @param beanFactory the bean factory used by the application context
    * @throws org.springframework.beans.BeansException in case of errors
    */
   void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException;

}

在Spring中内置了一些BeanFactoryPostProcessor实现类：