在Java中更改类

Image img = factory.newInstance(args);

abstract Image newInstance(args) 在你的 Image

这两种方法都依赖于这样一个事实,即两种类型的图像之间的参数相同,您可能需要传入一个超集来实现这两个构造函数。

如果这是一个选项(也许我没有得到这个问题),你应该使用 factory method pattern

abstract class Pizza {
    public abstract int getPrice(); // count the cents
}

class HamAndMushroomPizza extends Pizza {
    public int getPrice() {
        return 850;
    }
}

class DeluxePizza extends Pizza {
    public int getPrice() {
        return 1050;
    }
}

class HawaiianPizza extends Pizza {
    public int getPrice() {
        return 1150;
    }
}

class PizzaFactory {
    public enum PizzaType {
        HamMushroom,
        Deluxe,
        Hawaiian
    }

    public static Pizza createPizza(PizzaType pizzaType) {
        switch (pizzaType) {
            case HamMushroom:
                return new HamAndMushroomPizza();
            case Deluxe:
                return new DeluxePizza();
            case Hawaiian:
                return new HawaiianPizza();
        }
        throw new IllegalArgumentException("The pizza type " + pizzaType + " is not recognized.");
    }
}

class PizzaLover {
    /*
     * Create all available pizzas and print their prices
     */
    public static void main (String args[]) {
        for (PizzaFactory.PizzaType pizzaType : PizzaFactory.PizzaType.values()) {
            System.out.println("Price of " + pizzaType + " is " + PizzaFactory.createPizza(pizzaType).getPrice());
        }
    }
}

Output:
Price of HamMushroom is 850
Price of Deluxe is 1050
Price of Hawaiian is 1150

我理解你的问题有些困难。我试着在这里总结你的问题陈述,如果这确实是你的问题,请评论。