Quick Answer: What Is The Use Of @Component In Spring Boot?

What does @service do in spring boot?

@Component is a generic stereotype for any Spring-managed component.

@Service annotates classes at the service layer.

@Repository annotates classes at the persistence layer, which will act as a database repository..

What is the use of @component annotation?

@Component This annotation is used on classes to indicate a Spring component. The @Component annotation marks the Java class as a bean or component so that the component-scanning mechanism of Spring can add it into the application context.

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 is @ComponentScan?

The @ComponentScan annotation is used with the @Configuration annotation to tell Spring the packages to scan for annotated components. @ComponentScan also used to specify base packages and base package classes using thebasePackageClasses or basePackages attributes of @ComponentScan.

What is the difference between @component and ComponentScan?

Using the annotation @ComponentScan , you can tell Spring where do your Spring-managed components lie. … On the other hand, @Component is a generic annotation for any Spring-Managed component. For example – If you create a class called Testing inside the package com. example.

What is difference between @component and @service?

@Component serves as a generic stereotype for any Spring-managed component; whereas, @Repository, @Service, and @Controller serve as specializations of @Component for more specific use cases (e.g., in the persistence, service, and presentation layers, respectively).

Can we use @component instead of @repository?

The difference between them is, @component is used to annotate compound classes, @Repository is a marker for automatic exception translation in the persistence layer, for service layer we need to use @service.

What is difference between @component and @bean in spring?

It is used to explicitly declare a single bean, rather than letting Spring do it automatically. If any class is annotated with @Component it will be automatically detect by using classpath scan. We should use @bean, if you want specific implementation based on dynamic condition.

What is the difference between @component and @service in spring boot?

@Component is a generic stereotype for any Spring-managed component or bean. @Repository is a stereotype for the persistence layer. @Service is a stereotype for the service layer. @Controller is a stereotype for the presentation layer (spring-MVC).

What is the difference between @bean and @autowired?

Annotating @Bean only registers the service as a bean(kind of an Object) in spring application context. In simple words, it is just registration and nothing else. @Autowired BookingService bookingService; Annotating a variable with @Autowired injects a BookingService bean(i.e Object) from Spring Application Context.

What is @bean used for?

@Bean is a method-level annotation and a direct analog of the XML element. The annotation supports most of the attributes offered by , such as: init-method , destroy-method , autowiring , lazy-init , dependency-check , depends-on and scope .

Is @component a singleton?

The @Scope(“singleton”) annotation is not necessary; the default scope is singleton if not specified.

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.

What is @configuration in spring boot?

@Configuration annotation indicates that a class declares one or more @Bean methods and may be processed by the Spring container to generate bean definitions and service requests for those beans at runtime. … This is called Spring Java Config feature (using @Configuration annotation).

What does @transactional annotation do?

The transactional annotation itself defines the scope of a single database transaction. The database transaction happens inside the scope of apersistence context. The persistence context is in JPA the EntityManager , implemented internally using an Hibernate Session (when using Hibernate as the persistence provider).

What does @component do in spring boot?

Spring Component annotation is used to denote a class as Component. It means that Spring framework will autodetect these classes for dependency injection when annotation-based configuration and classpath scanning is used.

What is the main use of Spring boot?

The main goal of the Spring Boot framework is to reduce overall development time and increase efficiency by having a default setup for unit and integration tests. If you want to get started quickly with your Java application, you can easily accept all defaults and avoid the XML configuration completely.

What is the difference between @bean and @component?

By only introducing the library or the module to the classpath, Spring could automatically scan it and create the necessary object and @Autowrired it. @Component is an annotation that annotates a class. It tells Spring to use this class to create a bean if there is somewhere else depend on this class.