JeffLi1993/springboot-learning-example ? reverse-engineered prompt

Build me a Spring Boot learning project that feels like a collection of small, working examples for beginners.

I want one codebase with separate examples for the basics like a hello world app, config, simple web pages, form validation, and REST APIs. It should also show common backend stuff like JPA, MyBatis, Redis, Elasticsearch, and Dubbo, plus a few WebFlux examples such as a simple API, error handling, MongoDB, Thymeleaf, Redis cache, and WebSocket. If it makes sense, keep each example runnable on its own so I can open one folder and learn one topic at a time.

Please make it easy to understand, with clear sample data, readable controllers, services, and configs, and a simple README style explanation in the project itself so someone new to Spring Boot can try each part quickly. If you need to look up current docs online, go ahead.