java-spring

Scope

Covers server-side Java (and Kotlin) applications built on Spring Boot: the auto-configuration and configuration-property model, the web layer in both Spring MVC and WebFlux, outbound HTTP, persistence with Spring Data JPA and its transaction semantics, Spring Security, testing at every slice, Spring Modulith, Actuator/Micrometer instrumentation, the Maven or Gradle build, container and GraalVM native packaging, the Spring Boot 3.5 → 4 migration, and the Java 17 → 21 → 25 language upgrade a Spring codebase goes through alongside it.

The body is written against Spring Boot 4.1, the current GA line. Where Spring Boot 3.5 differs, the difference is in references/boot-4-migration.md rather than duplicated inline.

Not covered: