Reflection Use Cases

Reflection is not a curiosity tucked into java.lang.reflect. It is the engine inside almost every Java framework you have used. Spring, Hibernate, Jackson, JUnit, JPA, Lombok-at-runtime, and most testing libraries all use the same handful of reflection calls. This lesson shows how each of these tools uses reflection in practice, so the next time you write @Component or @Test, you can picture exactly what is happening on the other side. We will not re-teach the API. We will apply it.

The running example throughout is a small e-commerce domain: Product, Order, Cart, Customer. Each use case takes that domain and shows how reflection turns it into something useful.