public abstract class Factory {
    public final Product create(String owner) {
        Product p = createProduct(owner);
        registerProduct(p);
        return p;
    }
    protected abstract Product createProduct(String owner);
    protected abstract void registerProduct(Product product);
}

public abstract class Product {
    public abstract void use();
}

public class IDCard extends Product {
    private String owner;
    IDCard(String owner) {
        System.out.println(owner + "의 카드를 만듭니다.");
        this.owner = owner;
    }
    public void use() {
        System.out.println(owner + "의 카드를 만듭니다.");
    }
    public String getOwner() {
        return owner;
    }
}

public class IDCardFactory extends Factory {
    private Vector owners = new Vector();
    protected Product createProduct(String owner) {
        return new IDCard(owner);
    }
    protected void registerProduct(Product product) {
        owners.add(((IDCard)product).getOwner());
    }
    public Vector getOwners() {
        return owners;
    }
}