Spring Dependency Injection and Inversion of Control Container Concepts

Internal

• Spring Framework Concepts

Overview

At the heart of the Spring Framework are the modules that implement the core container, including a configuration model and a dependency injection mechanism. Support for different application architectures, including messaging, transactions and persistence is built in top of the core container.

Configuration Model

This section refers to component configuration. Configuration as in external data that is provided to the application in form of properties or environment variables, and that potentially modifies the behavior of the application, is addressed in the "Application Configuration Concepts" section.

XML-based Configuration

Java-based Configuration (@Configuration). Annotation injection is performed before XML injection, thus the XML configuration overrides the annotations for properties wired through both approaches.

Configuration time. Define what that is.

Component scanning.

Autowiring. @Autowired.

Automatic configuration (Spring Boot autoconfiguration).

Application Context

https://docs.spring.io/spring-framework/docs/5.1.0.RELEASE/javadoc-api/org/springframework/context/ApplicationContext.html

The application context provides:

• Bean factory functionality, inherited from ListableBeanFactory.
• Ability to load file resources, inherited from ResourceLoader.
• Ability to publish events to registered listeners, inherited from ApplicationEventPublisher.
• Ability to resolve messages, inherited from MessageSource.
• Inheritance from a parent context.

Beans

Bean name

Collaborator beans

Describe bean initialization process. Who does it?