spring-boot

Spring Boot — MIND CTI Development Standards

MIND CTI standard for Spring Boot 3.x (3.5+) projects. Detected in: MindBill-Authorization-Backend, MindBill-DrawerManagement-Backend, MindBill-DRS-Backend, MindBill-POS, MindBill-Selfcare-Backend, CcsSpendingLimitGateway, RoamingManager Processor.

When This Applies

This skill applies when the project has Spring Boot as a dependency (detected via spring-boot-starter-* in pom.xml). It supplements the java-core skill with Spring-specific patterns.

Target version: Spring Boot 3.x (3.5+ preferred). The RoamingManager Processor on Spring Boot 2.5.7 is legacy — migrate to 3.x when feasible.

Key version implications (Spring Boot 3.x):

• Jakarta namespace — jakarta.* not javax.*
• Spring Security 6 — new SecurityFilterChain API, no WebSecurityConfigurerAdapter
• Observation API — Micrometer-based tracing
• Java 17 baseline — can use records, sealed classes, text blocks

Core Principles

1. Convention over configuration — Use Spring Boot defaults unless there's a reason not to.
2. Constructor injection everywhere — @RequiredArgsConstructor + private final fields.
3. Layered architecture — Controller → Service → Repository. No shortcuts.
4. Externalized configuration — No hardcoded values. Use application.properties/application.yml with env var placeholders.
5. Undertow server — MIND CTI standard is Undertow, not Tomcat.

Quick Reference — Top 10 Spring Boot Rules

1. Constructor injection with @RequiredArgsConstructor. No field @Autowired.
2. @RestControllerAdvice for global exception handling (not ErrorAttributes override).
3. JpaRepository for all new repositories.
4. application.properties with ${ENV_VAR:default} for externalized config.
5. Undertow as embedded server (exclude Tomcat in starter-web).
6. Flyway for database migrations.
7. SpringDoc OpenAPI (2.6.0) for API documentation.
8. Spring Security + OAuth2/OIDC with Keycloak for authentication.
9. @WebMvcTest/@DataJpaTest slice tests preferred over full @SpringBootTest.
10. Actuator endpoints for health checks and metrics.

Detailed Reference

• For package layout and profile management → project-structure.md
• For controller design, DTOs, validation, and pagination → rest-api.md
• For service design and transaction management → service-layer.md
• For Spring Data JPA, entity mapping, and queries → data-access.md
• For Spring Security, OAuth2, and Keycloak → security.md
• For application properties, profiles, and externalized config → configuration.md
• For @SpringBootTest, slice tests, and MockMvc → testing.md
• For Actuator, health checks, and metrics → observability.md

MIND CTI Specific Notes

• Parent BOM: MindBill-BOM v10.00.002 manages Spring Boot version centrally
• Database: Oracle (ojdbc17) for production, H2 for tests
• Server: Undertow replaces Tomcat (better performance, fewer threads)
• Security: All projects use Keycloak OIDC via spring-boot-starter-oauth2-resource-server
• Caching: EhCache (with jakarta classifier) for L1, Redis optional for L2
• Legacy interop: Some Spring Boot services call V10.00 EJBs via wildfly-ejb-client-bom
• Logging: SLF4J + Logback (Log4j2 in some projects for security patch — 2.17.2+)