java - Spring中的ImportSelector和ImportBeanDefinitionRegistar有什么区别？

Question

1. ImportSelector 和 ImportBeanDefinitionRegistar 有什么区别？

2. 哪种场景应该使用 ImportSelector 或 ImportBeanDefinitionRegistar 以及为什么？

Answer 1

ImportSelector是一个

Interface to be implemented by types that determine which @Configuration class(es) should be imported based on a given selection criteria, usually one or more annotation attributes.

ImportBeanDefinitionRegistrar是一个

Interface to be implemented by types that register additional bean definitions when processing @Configuration classes. Useful when operating at the bean definition level (as opposed to @Bean method/instance level) is desired or necessary.

一方面，ImportSelector 用于根据给定条件导入配置，另一方面，ImportBeanDefinitionRegistrar 用于在处理配置时注册其他 bean。这是两种不同的用法。