$ show kousen/spring-and-spring-boot
This repository is a Spring Boot training/courseware package rather than a production service. It consists of five independent, runnable Spring Boot applications under com.kousenit (demo, restclient, persistence, shopping, springai), accompanied by lab workbooks (labs.md, advanced-labs.md), course slides (slides.md), and CI workflows. The code demonstrates current-generation Spring and Spring Boot patterns: MVC and REST controllers, Java records for DTOs, RestClient and HTTP interfaces, JdbcClient and JPA data access, AOP aspects, RFC 7807 exception handling, and Spring AI chat clients. Although the dominant character is application code, it is educational example code, not a deployed system.
The LLM identified 4 files worth highlighting for reuse:
A self-contained AspectJ aspect that logs method execution and timing, driven by a custom @Timed annotation. It is isolated from the rest of the demo application and can be copied into a new Spring project to add low-ceremony method-level metrics and tracing.
A @RestControllerAdvice that translates domain exceptions and validation failures into RFC 7807 ProblemDetail responses. It demonstrates a portable, consistent error-response pattern for Spring REST APIs and can be adapted to other domains by replacing the exception types.
A DAO built on Spring's fluent JdbcClient API, using named parameters and automatic row mapping. It shows the modern replacement for JdbcTemplate and is a clean template for building repository-style data access in new Spring applications.
A Spring service using RestClient to call OpenAI-compatible chat completions through OpenRouter, with configurable model and API key. It is a reusable integration pattern for adding LLM calls to a Spring Boot application while keeping the HTTP client and response parsing declarative.