Implementation permissions

You can create a rule for the service interface, that specifies, which classes may implement the interface.

@Service(permits = { MongoUserService.class, MySQLUserService.class })
interface UserService {
}

@Service
class MongoUserService implements UserService {
}

@Service
class MySQLUserService implements UserService {
}

@Service
class PostgresUserService implements UserService {
}

void initUserService() {
    Container.implement(UserService.class, MongoUserService.class);
    Container.implement(UserService.class, MySQLUSerService.class);
    // both should work fine
    
    Container.implement(UserService.class, PostgresUserService.class); 
    // will throw an `InvalidServiceAccessException`
}