Spring @Component, @Service, @Repository, @Controller Difference

Spring @Component, @Service, @Repository and @Controller annotations are used for automatic bean detection using classpath scan in Spring framework. @Component is a generic annotation. Difference of @Service, @Repository, @Controller with @Component is they are special cases of @Component and used for particular purposes. The difference is just classification only .

For all these annotations (stereotypes), technically the core purpose is same. Spring automatically scans and identifies all these classes that are annotated with “ @Component, @Service, @Repository, @Controller”  and registers BeanDefinition with ApplicationContext.

• In a multitier application, we will have different layers like presentation, service, business, data access etc. When a class is to be annotated for auto-detection by Spring, then we should use the respective stereotype as below.
• @Component – generic and can be used across application.
• @Service – annotate classes at service layer level.
• @Controller – annotate classes at presentation layers level, mainly used in Spring MVC.
• @Repository – annotate classes at persistence layer, which will act as database repository.

References Used :-  spring-component-service-repository-controller-difference