Why Package Structures Won't Save Your Spring Boot Architecture (And How Maven Enforces It) (Chapter 1)

How We Turned Architectural Guidelines Into Compilation Errors

Have you ever found yourself doing a Friday afternoon Code Review, only to discover that someone injected the EntityManager directly into a REST controller, writing raw SQL strings, and mapping rows manually with a loop? Or worse, have you seen a @RequestParam accepting org.springframework.data.domain.Pageable while the controller returns a raw Page<Entity> directly to the frontend?

Congratulations. You have just exposed your database schema to the entire world and completely bypassed the concept of an Anti-Corruption Layer (ACL).

The Illusion of Package Control

When an application is structured within a single module and we rely strictly on package separation (.controller, .service, .repository), we live in an illusion of architectural control.