What are the main steps and requirements for configuring and registering beans in the context of dependency injection?

To configure and register beans in a dependency injection context (for example, in the Spring Framework), the following steps are usually performed:

1. Define the bean class — create a class that will be managed by the container.

2. Annotation or configuration:

   • Use annotations, such as @Component, @Service, @Repository, for automatic scanning and registration.
   • Or explicitly declare the bean in a configuration class using @Bean.

3. Configure dependencies — via constructor, setters, or fields with the @Autowired annotation.

4. Register in the container — the IoC container automatically creates and manages the bean lifecycle.

Example using annotations:

@Component
public class MyService {
    // dependencies
    @Autowired
    private MyRepository repository;

    // methods
}

Or through configuration:

@Configuration
public class AppConfig {
    @Bean
    public MyService myService() {
        return new MyService(myRepository());
    }

    @Bean
    public MyRepository myRepository() {
        return new MyRepository();
    }
}

Main requirements:

• Classes should be available for scanning or explicitly declared.
• Dependencies should be correctly defined and accessible.
• The container should be configured to manage the bean lifecycle.