Spring Boot request validation and error responses with ProblemDetail
Validate incoming requests with Bean Validation and return consistent, standards-based error responses using ProblemDetail (RFC 9457) and @RestControllerAdvice.

A space to connect knowledge, one line of code a day.
Discover tutorials, ideas, and notes from a learning journey.
Validate incoming requests with Bean Validation and return consistent, standards-based error responses using ProblemDetail (RFC 9457) and @RestControllerAdvice.
Validate incoming requests with Bean Validation and return consistent, standards-based error responses using ProblemDetail (RFC 9457) and @RestControllerAdvice.
Replace scattered @Value annotations with validated, immutable configuration classes using @ConfigurationProperties and Java records.
Protect a stateless REST API with Spring Security's OAuth2 resource server support: validate JWTs, map roles, secure methods, and test it all with MockMvc.
Use Spring Boot Actuator to expose health checks, Kubernetes probes, application info, and Micrometer metrics, and learn how to keep those endpoints secure.
Run integration tests against real PostgreSQL databases in Docker with Testcontainers and @ServiceConnection, and reuse the same setup for local development.
Go beyond basic repositories: paginate and sort safely, fetch only the columns you need with projections, and detect and fix the N+1 query problem.
Stay curious. There is always something new to learn.
Writer and founder of Diary Coding — sharing notes, tutorials, and experiences about programming for anyone who wants to keep learning.