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.