Contexts and dependency injection

When designing an enterprise solution, one of the primary tasks is to divide your application into separate components that interact with each other. To avoid all the hassle of managing our components, their dependencies, and their life cycles, the contexts and dependency API (CDI) has been developed to be the backbone of component and dependency management. By components, we mean objects that encapsulate your application's business logic. By dependencies, we mean commonly used application-shared resources such as a database connection, user sessions, web service endpoints, and such.

In Chapter 2, Dependency Injection Using CDI 2.0, we'll learn how to create and use CDI beans, how to use bean scopes, how to provide different implementations of the same bean, and how to inject beans into other beans. Moreover, we'll learn about some more advanced topics, such as producers, interceptors, and events.