The core of Spring is the IOC container, which is essentially a collection of bean relationships. And to achieve it, there are three modules: beans, context, and core.
The beans package is mainly responsible for the definition, creation and analysis of beans. It uses the simple factory pattern top-level bean factory interface, the factory method pattern factory bean creation, and the template method pattern IOC container initialization.
Concext mainly defines, creates and maintains a collection of bean relationships, marks an application environment, and captures and publishes various events.
The core component provides various tools to complete the above functions. It abstracts all resources into an interface, shields the differences between different file types, and provides resource acquisition interfaces to shield the differences in resource loading.