Java Spring Framework: Component, Repository, Service-Differences

Question

Explain the difference between: Component, Repository, Service in the Java Spring Framework.

Give simple usage examples.

4

English java spring

Author: ragmon, 2015-11-25

Source

1 answers

score 14 · Accepted Answer

@Component - this is any arbitrary bin that Spring can find via autoscan.

Example: you have implemented a class and want to make its instance available via @Autowired.

The remaining annotations represent the layers of a typical multi-layer architecture:

@Repository - this is @Component with the semantics of the DAO layer. The place where you go to the database. Spring will wrap the exceptions thrown by the class in DataAccessException.
@Service - this is @Component with semantics business logic layer.
@Controller - this is @Component with the semantics of the web layer. Spring will turn such beans into servlets.