java-springboot

When to Use

• Developing Spring Boot applications
• Need best practices for Spring Boot
• Configuring Spring Boot projects
• Working with Spring framework components

Core Principles

1. Constructor Injection — Always use it for testability. Never @Autowired on fields.
2. DTOs — Never expose JPA entities to the API layer. Use records or projection interfaces.
3. Package by Feature — Group by domain (order/, user/), not by layer (controller/, service/).
4. Validation — Use Bean Validation (@Valid, @NotBlank) on request DTOs.
5. Transactions — Keep them short and at the service layer with @Transactional.
6. Logging — Use parameterized logging ({}), never string concatenation.
7. Security — Never hardcode secrets. Use env vars and @ConfigurationProperties.
8. Testing — Use the narrowest test slice that gives you confidence.
9. Configuration — Externalize everything via application.yml and @ConfigurationProperties.
10. Monitoring — Add Actuator and health checks to every service.

Reference Index

Commands

# Run Spring Boot application
mvn spring-boot:run

# Run with specific profile
mvn spring-boot:run -Dspring-boot.run.profiles=dev

# Build project
mvn clean package

# Run tests
mvn test

# Run specific test
mvn test -Dtest=OrderServiceTest

Testing

For comprehensive testing guidance (test slices, MockMvcTester, Testcontainers, AssertJ), see the java-springboot-testing skill.

Quick Reference

Context7 Integration

When you need up-to-date information on Spring Boot:

1. Resolve the libraryId — Use context7_resolve-library-id with:
   • libraryName: "spring boot" or "spring framework"
   • query: what you're going to do (e.g., "configuration properties", "custom health check")
2. Query the docs — Use context7_query-docs with:
   • libraryId: the ID from the previous step (e.g., "/spring/spring-boot")
   • query: your specific question

Before answering about Spring Boot APIs, configurations, or best practices, consult Context7 to get up-to-date information.

Resources

• Spring Boot Documentation
• Spring Framework Documentation
• Spring Security Documentation