Whether IoC is reasonable or not does not depend on the number of classes in the project. It is still a useful pattern even if you have, like, 3 classes (compon

Whether IoC is reasonable or not does not depend on the number of classes in the project. It is still a useful pattern even if you have, like, 3 classes (component A using implementation B of the interface Ib). It's just if you have only few components, you may want to wire them manually in maybe 10 lines of code instead of dropping in Spring JARs.