...The repository provides multiple standalone demos (e.g., web, scheduling, persistence, messaging, caching, Docker) to help beginners quickly grasp common components and idioms. The author notes that all examples have been updated to Spring Boot 3.0, with earlier 1.x and 2.x code paths kept accessible for reference. Each sample focuses on a single topic—such as Web MVC, WebFlux, Thymeleaf, JPA/MyBatis CRUD, file upload, Redis/MongoDB, RabbitMQ, and containerization—so you can learn one concept at a time and compose them later. ...