Most enterprise Java applications are driven by annotations. Java annotations encapsulate many different functionalities. Here, I’ll introduce some of the most popular annotations and explain what they are responsible for to sure up your understanding of annotations you’re already familiar with and introduce you to ones you may not know.
Inversion of Control and Dependency Injection
These two patterns are responsable for bean initialization. IOC initializes beans and defines dependencies between them, while DI allows you to use them in your class without calling a constructor. There’s much more you can do with these, but for the sake of brevity, we’ll stop here.