NOTE
Spring MVC Auto-Configuration in Spring Boot
How Boot conditionally configures MVC defaults while allowing application customization and full override.
This is a historical learning note and may contain outdated or incomplete understanding.
When the MVC stack is present and applicable, Spring Boot contributes common MVC infrastructure and defaults such as message conversion, formatting, resource handling, error/application integration, and configuration adapters.
Applications can usually customize MVC through supported configuration hooks/beans without replacing every default. Taking full manual control can disable portions of Boot’s MVC auto-configuration, depending on the version and configuration approach.
Because the exact auto-configured beans have evolved, reason from conditions and extension contracts rather than one historical list of internal classes.