2.2. @Exact
Annotating an injection point with @Exact allows you to select an exact implementation of the injection point type to inject. For example:

interface PaymentService {
...
}

class ChequePaymentService implements PaymentService {
...
}

class CardPaymentService implements PaymentService {
...
}

class PaymentProcessor {
@Inject @Exact(CardPaymentService.class)
PaymentService paymentService;
...
}