Inversion of control containers and the dependency injection pattern

Martin Fowler. Inversion of control containers and the dependency injection pattern. \url{http://martinfowler.com/articles/injection.html}, January 2004.

Abstract

In the Java community there’s been a rush of lightweight containers that help to assemble components from different projects into a cohesive application. Underlying these containers is a common pattern to how they perform the wiring, a concept they refer under the very generic name of “Inversion of Control”. In this article I dig into how this pattern works, under the more specific name of “Dependency Injection”, and contrast it with the Service Locator alternative. The choice between them is less important than the principle of separating configuration from use.