Learn Resilience4j as the modern Spring Boot 3 replacement for Hystrix: Circuit Breaker, Retry, Rate Limiter, and Bulkhead patterns with full application.yml configuration, annotated Java code, and Actuator monitoring.
Learn how to implement ETag cache control in Spring Boot REST APIs: ShallowEtagHeaderFilter, manual checkNotModified(), conditional PUT with If-Match, optimistic locking, and strong vs weak ETags — with curl test examples.
Build a complete file-upload REST endpoint with Jersey 3.x: single file, multiple files, HTML form testing, curl commands, file-size limits, and a download endpoint. Includes production-hardening tips for cloud storage and MIME validation.
Learn how to add HTTP Basic Auth, JWT Bearer tokens, and role-based access control to Jersey JAX-RS REST APIs. Covers ContainerRequestFilter, SecurityContext, annotations, and Spring Boot integration with annotated Java code.
Build a custom Maven archetype from scratch: create the descriptor, add Velocity-templated source files, install locally, generate a new Spring Boot project from it, and deploy to a team-shared repository. Step-by-step with working code.
A practical deep dive into Java Message Service (JMS): core concepts, queue vs topic messaging, synchronous and asynchronous consumers, publish-subscribe with Apache ActiveMQ, Spring Boot JmsTemplate, and production best practices.
Master Logback RollingFileAppender with time-based, size-and-time, and fixed-window rolling policies. Includes production-ready logback.xml examples, Spring Boot integration, async logging, and a complete FAQ.
A complete beginner's guide to building a REST API with Spring Boot 3. Covers project setup, clean package structure, a Java record model with Bean Validation, a service layer, a @RestController with GET/POST/PUT/DELETE endpoints, global exception handling with @RestControllerAdvice, and end-to-end curl testing u2014 with fully annotated code throughout.
A complete guide to testing microservices with JUnit 6: single-service integration tests with WireMock, consumer-driven contract tests with Spring Cloud Contract, and end-to-end tests with Docker Compose and Testcontainers. Covers async event testing and state management strategies.
A complete guide to testing REST APIs with JUnit 6 using both MockMvc and WebTestClient. Covers GET, POST, PUT, DELETE testing, JSON path assertions, validation error testing, file uploads, authentication, and a matcher quick-reference table.