Topics Spring Boot

Spring Boot (12)

12 posts · 32tags

September 2026

Spring Cache:Stop Querying for the Same Order Twice

Cache order reads with Spring @Cacheable and in-process Caffeine, evict on update, and keep JPA entities out of the cache.

Spring Boot

Flyway Without the `ddl-auto` Roulette

Version the orders schema with Flyway SQL migrations, turn off Hibernate ddl-auto outside local experiments, and prove the script with Testcontainers.

Spring Boot

When `@Valid` Fails, the Body Should Help:Problem Details and `@ControllerAdvice`

Turn Bean Validation failures and domain exceptions into RFC 7807 ProblemDetail responses with @ControllerAdvice so API clients get a body they can actually use.

Spring Boot

Profiles and Secrets:Stop Baking Production Into the Jar

Split Spring Boot config by profile, bind settings to a @ConfigurationProperties record, and inject secrets from the environment instead of committing them in the jar.

Spring Boot

RestClient After RestTemplate:One Client, Bounded Waits, Errors You Handle

Replace ad-hoc HTTP calls with Spring Boot 3 RestClient: inject the managed Builder, set timeouts, map JSON to records, and handle status codes without RestTemplate ceremony.

August 2026

Spring Boot

Spring Boot Observability:Health, Metrics, and Correlation IDs

Build an observable Spring Boot service with Actuator health probes, Prometheus metrics, W3C trace context, request IDs, and production-safe endpoint security.

Spring Boot

Testing Slices + Testcontainers:Fast Tests Without Booting the Whole App

Choose focused Spring Boot test slices and verify a Spring Data JPA repository against a real PostgreSQL database with Testcontainers.

Spring Boot

Spring Security Basics at the Service

Turn a Spring Boot API into an OAuth2 resource server, validate JWTs locally, and authorize business actions with method security instead of trusting the edge alone.

Spring Boot

REST API with Boot 3 + Records as DTOs

Design a Spring Boot 3 REST boundary with Java records, Bean Validation, Jackson, and explicit mapping to service-owned models.

Spring Boot

Spring Data JPA Footguns:Entities vs Records, N+1, Transactions

Build a safe Spring Data JPA boundary with proxy-friendly entities, record DTOs, explicit fetch plans, and service-owned transactions.

Spring Boot

Spring Boot Virtual Threads:Flip One Flag, Then Fix What Breaks

Enable spring.threads.virtual.enabled on Boot 3.2+, understand what Tomcat and the application task executor actually switch, and size Hikari, RestClient, and observability so the flag does not become a thundering herd.

Spring Boot

Spring Cloud Gateway:Put a Front Door on Your Microservices

When to put an API gateway in front of your services, the trade-offs that matter, and a working Spring Cloud Gateway Server Web MVC example on the Servlet stack.