- How does annotation work in spring?
- What is a bean in spring?
- Which Dependency injection is better in spring?
- What is spring bean life cycle?
- What are the bean scopes in spring?
- What is @bean annotation in spring?
- Why does spring recommend constructor injection?
- Which injection is better in spring?
- What is the use of @repository annotation in spring?
- What is the difference between @component and @bean?
- What annotation can you use to inject a Spring bean?
- What does @service annotation in spring?
- Why annotation is used in spring?
- Which Di is better in spring?
How does annotation work in spring?
Spring could use its own classloader to load required classes.
At runtime, when the class is loaded and Spring determines it has some appropriate annotation, it injects bytecode to add additional properties or behavior to the class..
What is a bean in spring?
In Spring, the objects that form the backbone of your application and that are managed by the Spring IoC container are called beans. A bean is an object that is instantiated, assembled, and otherwise managed by a Spring IoC container. Otherwise, a bean is simply one of many objects in your application.
Which Dependency injection is better in spring?
A constructor therefore enforces the dependency requirement whether or not you’re using Spring, making it container-agnostic. If you use setter injection, the setter may or may not be called, so the instance may never be provided with its dependency.
What is spring bean life cycle?
A “Spring bean” is just a Spring managed instantiation of a Java class. The Spring IoC container is responsible for instantiating, initializing, and wiring beans. The container also manages the life cycle of beans. Spring provides several ways through which you can tap into the bean lifecycle.
What are the bean scopes in spring?
Spring – Bean ScopesSr.No.Scope & Description1singleton This scopes the bean definition to a single instance per Spring IoC container (default).2prototype This scopes a single bean definition to have any number of object instances.3 more rows
What is @bean annotation in spring?
Annotating a class with the @Configuration indicates that the class can be used by the Spring IoC container as a source of bean definitions. The @Bean annotation tells Spring that a method annotated with @Bean will return an object that should be registered as a bean in the Spring application context.
Why does spring recommend constructor injection?
The Spring team generally advocates constructor injection as it enables one to implement application components as immutable objects and to ensure that required dependencies are not null. Furthermore, constructor-injected components are always returned to client (calling) code in a fully initialized state.
Which injection is better in spring?
If we use both constructor and setter injection, IOC container will use the setter injection. Changes: We can easily change the value by setter injection. It doesn’t create a new bean instance always like constructor. So setter injection is flexible than constructor injection.
What is the use of @repository annotation in spring?
@Repository is a Spring annotation that indicates that the decorated class is a repository. A repository is a mechanism for encapsulating storage, retrieval, and search behavior which emulates a collection of objects.
What is the difference between @component and @bean?
@Component is a class level annotation whereas @Bean is a method level annotation and name of the method serves as the bean name. @Component need not to be used with the @Configuration annotation where as @Bean annotation has to be used within the class which is annotated with @Configuration.
What annotation can you use to inject a Spring bean?
Inject. The @Autowired annotation belongs to the org. springframework. beans.
What does @service annotation in spring?
Advertisements. Service Components are the class file which contains @Service annotation. These class files are used to write business logic in a different layer, separated from @RestController class file.
Why annotation is used in spring?
Starting from Spring 2.5 it became possible to configure the dependency injection using annotations. So instead of using XML to describe a bean wiring, you can move the bean configuration into the component class itself by using annotations on the relevant class, method, or field declaration.
Which Di is better in spring?
On the other hand, constructor injection uses the constructor to inject dependency on any Spring-managed bean. 2) Because of using the setter method, setter Injection in more readable than constructor injection in Spring configuration file usually applicationContext.