Spring Boot Java Base

Required Practices

• Use constructor injection only.
• Validate inbound DTOs with jakarta.validation annotations and @Valid.
• Keep entities separate from API DTOs.
• Use explicit transaction boundaries in service methods.
• Add centralized exception mapping with @RestControllerAdvice.
• Prefer optimistic locking (@Version) for mutable aggregate roots.
• Add pagination for list endpoints by default.
• Use structured logs that include request/correlation identifiers.
• Target Spring Boot 4 baselines: Java 17+, Jakarta EE 11, Servlet 6.1, Spring Framework 7.x.

Testing Standard

• Add unit tests for service decisions and edge cases.
• Add slice/integration tests for persistence and controller behavior.
• Cover success and failure paths: validation errors, not-found, conflict, and forbidden.
• Use Testcontainers for database-sensitive integration tests when SQL behavior matters.
• Use technology-specific Boot 4 test starters (for example, spring-boot-starter-security-test for security test utilities).
• Use spring-modulith-starter-test for application-module verification and integration tests.

Resource Loading

• Load references/base-patterns.md for reusable endpoint, persistence, security, and testing checklists before implementing medium or large backend changes.
• Load references/modulith-boot4-conventions.md before changing dependencies, migration rules, or module boundaries.