What Are Spring Stereotypes?

What are the stereotype annotations in Spring boot?

Stereotype annotations denote roles of types or methods at conceptual level. Stereotype annotations are

@Component , @Service , @Repository and @Controller annotations

. These annotations are used for auto-detection of beans using @ComponentScan and component-scan . The Spring stereotype @Component is parent stereotype.

What is generic stereotype?

Generic stereotypes are

generically formulated generalizations that express a stereotype

, like “Mexican immigrants are rapists” and “Muslims are terrorists.” Stereotypes like these are offensive and should not be asserted by anyone.

What are Spring components?

@Component is

an annotation that allows Spring to automatically detect our custom beans

. In other words, without having to write any explicit code, Spring will: Scan our application for classes annotated with @Component. Instantiate them and inject any specified dependencies into them.

What are stereotypes in Java?

A stereotype

allows a framework developer to identify such a role and declare some common metadata for beans with that role in a central place

. A bean may declare zero, one or multiple stereotypes, by applying the stereotype annotation to the bean class or producer method or field.

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

@Component auto detects and configures the beans using classpath scanning whereas

@Bean explicitly declares a single bean

, rather than letting Spring do it automatically.

What’s the difference between @component @controller @repository & @service annotations in Spring?

Their only difference comes in their purpose i.e. @Controller is used in Spring MVC to define controller, which are

first Spring bean and then the controller

. Similarly, @Service is used to annotated classes that hold business logic in the Service layer and @Repository is used in the Data Access layer.

What is the difference between @component and @service?

@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 @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 difference between @controller and @RestController?

The @Controller is a annotation to mark class as Controller Class in Spring While @RestController is used in REST Web services and similar to @Controller and @ResponseBody. … The key difference is

that you do not need to use @ResponseBody on each and every handler method once you annotate the class with @RestController

.

What is spring repository?

Spring @Repository annotation is used to indicate that

the class provides the mechanism for storage, retrieval, search, update and delete operation on objects

.

What is @configuration in spring?

@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 is @controller in spring?

Controller – A controller contains the business logic of an application. Here, the @Controller annotation

is used to mark the class as the controller

. … Front Controller – In Spring Web MVC, the DispatcherServlet class works as the front controller. It is responsible to manage the flow of the Spring MVC application.

What is the use of @SpringBootApplication?

We use the @SpringBootApplication annotation in our Application or Main class

to enable a host of features

, e.g. Java-based Spring configuration, component scanning, and in particular for enabling Spring Boot’s auto-configuration feature.

What is the use of stereotypes in spring?

Stereotype annotations are

markers for any class that fulfills a role within an application

. This helps remove, or at least greatly reduce, the Spring XML configuration required for these components. These annotations are used to stereotype classes with regard to the application tier that they belong to.

What does @bean do in spring boot?

Spring @Bean annotation tells that

a method produces a bean to be managed by the Spring container

. It is a method-level annotation. During Java configuration ( @Configuration ), the method is executed and its return value is registered as a bean within a BeanFactory .