Briefly describe your understanding of the Spring framework IOC and AOP.

IoC is the creation of objects, and the dependencies are controlled by Spring and configuration files. AOP is to add the same function to some similar methods, such as logs and transactions.

Spring framework is a hierarchical architecture, which consists of seven well-defined modules. Spring module is built on the core container, which defines the way to create, configure and manage bean.

Each module (or component) that makes up the Spring framework can exist alone or be implemented together with one or more other modules.

Objects in Spring applications provide transaction management services. By using Spring AOP, declarative transaction management can be integrated into applications without relying on EJB components.

Spring MVC framework: MVC framework is a full-featured MVC implementation for building Web applications. Through the policy interface, the MVC framework becomes highly configurable, and MVC accommodates a large number of view technologies, including JSP, Velocity, Tiles, iText and POI.

The functions of Spring framework can be used on any J2EE server, and most of them are also suitable for unmanaged environment. The core point of Spring is to support reusable business and data access objects that are not bound to specific J2EE services. Undoubtedly, such objects can be reused in different J2EE environments (Web or EJB), independent applications and test environments.