Can you explain the purpose of the @Repository annotation in Spring and how it is used in working with databases?

The @Repository annotation in Spring is used to designate a class as a component responsible for data access (DAO — Data Access Object). It serves as a marker for Spring to automatically register this class as a bean and apply specific processing to it, such as translating database exceptions into unified Spring exceptions (DataAccessException).

Using @Repository helps to:

• Organize the data access layer.
• Ensure automatic exception handling related to the database.
• Integrate with Spring mechanisms such as transactions.

Example:

@Repository
public class UserRepository {
    @Autowired
    private JdbcTemplate jdbcTemplate;

    public User findById(Long id) {
        return jdbcTemplate.queryForObject(
            "SELECT * FROM users WHERE id = ?", 
            new Object[]{id}, 
            new BeanPropertyRowMapper<>(User.class));
    }
}