M04 Q22 How do you customize Spring auto configuration?

You can customize Spring Auto Configuration by creating your own autoconfiguration module with Auto Configuration Class.

To do that, you need to create java jar module which will contain METAINF/spring.factories file that contains org.springframework.boot.autoconfigure.EnableAutoConfiguration entry, which points to your Auto Configuration Class.

Auto Configuration Class is a class annotated with @Configuration annotation, usually used together with @ConditionalOnClass annotation. Additionally, you can use @PropertySource annotation with @EnableConfigurationProperties and @ConfigurationProperties annotations to introduce custom properties for your auto-configuration module.

Inside Auto Configuration Class you should have @Bean annotated methods, which will provide configured beans when @ConditionalOnClass is met.