What's the difference between @Component, @Repository & @Service annotations in Spring?

Question

Can @Component, @Repository and @Service annotations be used interchangeably in Spring or do they provide any particular functionality besides acting as a notation device?

Answer 1

@Component, @ Repository, @ Service, @Controller:

@Component is a generic stereotype for the components managed by Spring @Repository, @Service, and @Controller are @Component specializations for more specific uses:

• @Repository for persistence
• @Service for services and transactions
• @Controller for MVC controllers

Why use @Repository, @Service, @Controller over @Component? We can mark our component classes with @Component, but if instead we use the alternative that adapts to the expected functionality. Our classes are better suited to the functionality expected in each particular case.

A class annotated with @Repository has a better translation and readable error handling with org.springframework.dao.DataAccessException. Ideal for implementing components that access data (DataAccessObject or DAO).

An annotated class with @Controller plays a controller role in a Spring Web MVC application

An annotated class with @Service plays a role in business logic services, example Facade pattern for DAO Manager (Facade) and transaction handling