Spring Beans
About
Spring Beans are the central components of a Spring application. In the Spring Framework, a bean is simply an object that is managed by the Spring Inversion of Control (IoC) container. When you use Spring, instead of manually instantiating objects with new, Spring creates and manages those objects for you. These objects are called beans.
Think of a Spring bean as a building block of your application: it could be a service, a data access object, a utility class, or even a controller—anything that Spring manages and wires into other parts of your code.
Why Spring Beans Matter ?
Spring’s entire architecture revolves around beans:
They promote loose coupling through dependency injection.
They centralize object management, improving testability and reusability.
They allow configuration flexibility using Java config, XML, or annotations.
Beans form the backbone of Spring modules like Spring MVC, Spring Data, Spring Security, and more.
Without understanding beans, you miss the core benefit Spring provides: object management with minimal boilerplate.
How Spring Creates and Manages Beans ?
When Spring starts up, it:
Scans for classes annotated with bean-related annotations (like
@Component,@Service, etc.).Instantiates those classes and registers them in the ApplicationContext.
Resolves dependencies between beans and injects them where needed.
Manages their lifecycle, including initialization and destruction (optional hooks like
@PostConstruct,@PreDestroy).
Use Cases of Spring Beans ?
Defining services that contain business logic
Managing repositories for database access
Creating configuration beans for third-party integrations
Injecting utility components across multiple classes
Ensuring reusability and testability by letting Spring manage objects
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