所有的工厂方法都应该是公开的吗？

// 抽象产品接口
interface Product {
    void use();
}

// 具体产品类
class ConcreteProductA implements Product {
    @Override
    public void use() {
        System.out.println("Using ConcreteProductA");
    }
}

class ConcreteProductB implements Product {
    @Override
    public void use() {
        System.out.println("Using ConcreteProductB");
    }
}

// 抽象工厂类
abstract class Creator {
    abstract Product factoryMethod();
}

// 具体工厂类
class ConcreteCreatorA extends Creator {
    @Override
    Product factoryMethod() {
        return new ConcreteProductA();
    }
}

class ConcreteCreatorB extends Creator {
    @Override
    Product factoryMethod() {
        return new ConcreteProductB();
    }
}

// 客户端代码
public class Client {
    public static void main(String[] args) {
        Creator creator = new ConcreteCreatorA();
        Product product = creator.factoryMethod();
        product.use();
    }
}