Hands-On High Performance with Spring 5

The @Qualifier annotation

Handling multiple autowire candidates with @Primary is more effective when only one primary candidate can be determined for multiple autowire candidates. The @Qualifier annotation gives you more control over the selection process. It allows you to give a reference associated with a specific bean type. That reference can be used to qualify the dependency that needs to be autowired. Let's look at the following code:

@Componentpublic class AccountService implements CustomerService {}@Component@Qualifier("BankingService")public class BankingService implements CustomerService { }@Componentpublic class SomeService {    private CustomerService customerService;  @Autowired  @Qualifier("bankingservice") public BankingService(CustomerService ...