Summary
This chapter helped you learn about Spring's key concepts: beans, dependency injection, and AOP. You also learned how to define the scope of beans, and create ApplicationContext programmatically and use it to get the beans. Now, you can define beans' configuration metadata using Java and annotations and have learned how to use different beans of the same type.
You also implemented a sample Aspect – a cross-cutting concern using a modular approach, and learned the key concepts of the AOP programming paradigm.
Since we are going to implement REST APIs in this book, it is important to understand the Servlet Dispatcher concept.
In the next chapter, we'll implement our first REST API application using the OpenAPI Specification and use the Spring controller to implement it.