说明：  简单地说，Spring 是一个以控制倒置(Inversion of Control)原则为基础的轻量级框架。控制倒置是一个用于“基于组件的体系结构”的设计模式，它将“判断依赖关系”的职责移交给容器，而不是由组件本身来判断彼此之间的依赖关系。当在Spring内实现组件时, 容器“轻量级”的方面就展现出来了：针对Spring开发的组件不需要任何外部库；而且, 容器是轻量级的，它避免了像EJB容器那样的重量级方案的主要缺点，例如启动时间长、测试复杂、部署和配置困难，等等。
(In short, Spring is a control inversion (Inversion of Control) based on the principle of lightweight framework. Inversion is a control for the component-based architecture design mode, it will determine the dependence relations duties transferred to the container, and not by the component itself to determine the relationship between dependence. When in the Spring when the realization of components, containers flyweight out on the show: Spring for the development of components does not require any external library Moreover, the containers are lightweight, as it avoids the EJB container as heavyweight program s main shortcomings, such as long start-up time, test complexity, deployment, and configuration problems, and so on.)