Question 12

Explanation

Using @Autowired

@Autowired annotation on such a constructor is no longer necessary if the target bean defines only one constructor to begin with.

https://docs.spring.io/spring-framework/reference/core/beans/annotation-config/autowired.html

required

Declares whether the annotated dependency is required.

Defaults to true.

https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/beans/factory/annotation/Autowired.html

5. Autowire Disambiguation

By default, Spring resolves @Autowired entries by type. If more than one bean of the same type is available in the container, the framework will throw a fatal exception.

To resolve this conflict, we need to tell Spring explicitly which bean we want to inject.

https://www.baeldung.com/spring-autowire#disambiguation

Collection

You can also instruct Spring to provide all beans of a particular type from the ApplicationContext by adding the @Autowired annotation to a field or method that expects an array of that type.

public class MovieRecommender {
 
	private Set<MovieCatalog> movieCatalogs;
 
	@Autowired
	public void setMovieCatalogs(Set<MovieCatalog> movieCatalogs) {
		this.movieCatalogs = movieCatalogs;
	}
 
	// ...
}

https://docs.spring.io/spring-framework/reference/core/beans/annotation-config/autowired.html