Sample Java Abstract Factory

Application.java

interface PersistenceService {
    void save();
}

class DatabasePersistenceService implements PersistenceService {

    public void save() {
        // save to database
    }

}

class MemoryPersistenceService implements PersistenceService {

    public void save() {
        // save to memory
    }

}


class ServiceFactory {

    private static PersistenceService persistenceService;

    public static PersistenceService getPersistenceService() {
        return persistenceService;
    }

    public static void setPersistenceService(PersistenceService persistenceService) {
        ServiceFactory.persistenceService = persistenceService;
    }
}

public class Application {

    public static void main(String[] args) {

        ServiceFactory.setPersistenceService(new DatabasePersistenceService());
        PersistenceService persistenceService = ServiceFactory.getPersistenceService();
        persistenceService.save();

    }

}