Spring Boot Skill

Apply the practices below when developing Spring Boot applications. Read the linked reference only when working on that area.

Maven pom.xml Configuration

Read references/spring-boot-maven-config.md for Maven pom.xml configuration with supporting plugins and configurations to improve code quality, and testing.

Package structure

Read references/code-organization.md for domain-driven, module-based package layout and naming conventions.

Spring Data JPA

Implement the repository and entity layer using references/spring-data-jpa.md.

Service layer

Implement business logic in the service layer using references/spring-service-layer.md.

Spring MVC REST APIs

Implement REST APIs with Spring MVC using references/spring-webmvc-rest-api.md.

Spring Modulith

Build a modular monolith with Spring Modulith using references/spring-modulith.md.

Thymeleaf

If Thymeleaf is used for view templates, refer references/thymeleaf.md

Testing

Write tests at complementary levels — unit, sliced Spring tests, and at least one end-to-end/smoke test; the levels are not either/or. Most framework-touching tests belong at the fast sliced level (@SpringBootTest(classes = …) or a slice annotation); keep full-context @SpringBootTest for a smoke test plus a request-level end-to-end. For why the levels are complementary and how to keep a large suite fast (context caching, one container for the suite), read references/testing-strategy.md.

What you're testing	Level	Reference
Business/domain logic, no framework	Unit (no Spring context)	testing-unit-mocking.md
JPA / JDBC / JdbcClient / Spring Data JDBC / jOOQ queries	Persistence slice + Testcontainers	testing-slices-persistence.md
Controller, JSON serialization, or a REST client	Web slice (@WebMvcTest/@JsonTest/@RestClientTest)	testing-slices-web.md
A few components together, external HTTP (WireMock), or a startup/request-level smoke test	Sliced @SpringBootTest(classes = …) or smoke test	testing-integration.md
Full REST API over a real port, full BaseIT suite (RestTestClient)	End-to-end	spring-boot-rest-api-testing.md
A view-rendering controller (MockMvcTester)	Web slice	spring-boot-webapp-testing-with-mockmvctester.md
Wiring a container (@ServiceConnection / dynamic properties)	—	testcontainers-wiring.md

All persistence and integration tests use Testcontainers with a real database (never in-memory H2); see references/testcontainers-wiring.md for @ServiceConnection vs dynamic-property wiring.

Write ArchUnit Tests

To write tests for testing the architecture using ArchUnit, refer references/archunit.md

Spring Boot Docker Compose Support

To use Docker Compose support for local development, refer references/spring-boot-docker-compose.md.

Taskfile

Use references/taskfile.md for easier commands execution.