The Genius of Spring

The Genius of Spring

IoC + AOP

Dependency Injection = component assembly
                     = implementation injection (implementation substitution)
                     = testability (stubs)
                     = composability
                     = extensibility

AOP = change (unanticipated requirements)
    = infrastructure use cases
    = scattering
    = tangling
    = insufficient modularity
    = environment implementation instead of module by module implementation (e.g., DBC contract checking)

Both together enable component based development, test driven development, very high modularity. At a higher level, enable system features that are very difficult to provide on a module by module basis.