Design concepts behind Spring Framework

The design of Spring Framework is motivated by a set of design patterns and best practices that have evolved in the industry to address the complexity of Object Oriented Programming, including:

• Simple, noninvasive, and lightweight POJO (Plain Old Java Objects) programming, without having a need for complex application servers
• Loosely-coupled dependencies, achieved by applying the concepts of program to interfaces and composition over inheritance, which are the underlying design principles of design patterns and frameworks
• Highly configurable systems composed of objects with externalized Dependency Injection
• Templated abstractions to eliminate repetitive, boilerplate code
• Declarative weaving of cross-cutting aspects without polluting business components

Spring implements established design principles and patterns into its elegant components and promotes their use as the default design approach in applications built using Spring. This noninvasive approach lets you engineer robust and highly maintainable systems composed of loosely coupled components and objects written in clean and modular code. Spring Framework components, templates, and libraries realize the goals and concepts explained earlier in the chapter, leaving you to focus on your core business logic.