CDI
CDI (Contexts and Dependency Injection) is a Java EE specification that provides a dependency injection framework for managing component lifecycles and dependencies in Java applications. It enables loose coupling between components by allowing the container to inject dependencies at runtime, based on contextual scopes like request, session, or application. CDI is integral to modern Java EE and Jakarta EE platforms, facilitating the development of scalable and maintainable enterprise applications.
Developers should learn CDI when building enterprise Java applications, particularly with Java EE or Jakarta EE, as it standardizes dependency injection and simplifies component management. It is essential for creating decoupled, testable code in web applications, microservices, and large-scale systems where managing object lifecycles and dependencies manually would be cumbersome. Use cases include web services, REST APIs, and applications requiring complex business logic with multiple interacting components.