如何在一个grandparentclass中拥有所有的parentclass而不获得grandparentclass的所有属性？

Question

我对 Java 比较陌生，只学了一个星期，所以我还很缺乏经验。我在多态性上花了几天时间，知道我可以将 parent class 扩展为 child class，但我想知道如何拥有一个 grandparent class 具有 parent class 的所有属性。我做了一些研究，但没有找到我要找的东西。我正在做的是制作 objects 的衣服。我有一个 grandparent 是 'Clothing' 三个 parents 'Upper_wear', 'Lower_wear', and 'Shoes' 还有很多 children 这样的如 't-shirts'、'shorts' 和 'sandals'。目前我在 parents 代码中的内容是：

public class Upper_wear
{
    private String fabric;
    private int numb_zippers;
    private String draw_string;
    private int numb_pockets;
    private int size;
    private String color;
    private double length_sleeves;
    private int length_shirt;
    private String collar;
    private String hood;
    private int code;
    private double price;
    private String name;
    Upper_wear(String fabric,int numb_zippers,String draw_string,int numb_pockets,int size,String color, double length_sleeves, int length_shirt, String collar, String hood, int code, double price, String name){
        this.fabric = fabric;
        this.numb_zippers = numb_zippers;
        this.draw_string = draw_string;
        this.numb_pockets = numb_pockets;
        this.size = size;
        this.color = color;
        this.length_sleeves = length_sleeves;
        this.length_shirt = length_shirt;
        this.collar = collar;
        this.hood = hood;
        this.code = code;
        this.price = price;
        this.name = name;

    }
    public String get_fabric(){
        return fabric;
    }
    public int get_numb_zippers(){
        return numb_zippers;
    }
    public String get_draw_string(){
        return draw_string;
    }
    public int get_numb_pockets(){
        return numb_pockets;
    }
    public int get_size(){
        return size;
    }
    public String get_color(){
        return color;
    }
    public double get_length_sleeves(){
        return length_sleeves;
    }
    public int get_length_shirt(){
        return length_shirt;
    }
    public String get_collar(){
        return collar;
    }
    public String get_hood(){
        return hood;
    }
    public int get_code(){
        return code;
    }
    public double get_price(){
        return price;
    }
    public String get_name(){
        return name;
    }
}

对于 children 的代码，我有：

public class Jacket extends Upper_wear
{
    Jacket(String fabric,int numb_zippers,String draw_string,int numb_pockets,int size,String color, double length_sleeves, int length_shirt, String collar, String hood, int code, double price, String name){
        super(fabric, numb_zippers, draw_string, numb_pockets, size, color, length_sleeves, length_shirt, collar, hood, code, price, name);
    }
}

我之所以不只是用所有变量来扩展服装，是因为我不想说明 'Upper_wear' 是否有 'Shoe_laces'，这是 [=30] 中的一个变量=].然而，我想把所有 parent class 都收集起来，因为当我去运行 class 时。在 for 循环中，我想列出每件衣服的价格，而不仅仅是 parent class 的价格。我觉得我一次只能迭代一个 parent class，例如我目前拥有的：

public class Run
{
    public static void main (String[]args){
        Shoes Tennis_shoes_01 = new Shoes("Canvas", 0, "yes", 10, "red and white", 0,0.5,2.5, 00001, 750.99,"Tenny shoey");
        Upper_wear T_shirt_01 = new Upper_wear("Cotton", 0, "no", 0, 14, "yellow", 14.5, 15, "v-neck", "no", 00002, 990.50, "Yel-ow");)

        Shoes[]In_Stock = {Tennis_shoes_01};
        Upper_wear[]In_Stock_upper = {};
        Lower_wear[]In_Stock_lower = {};


        System.out.println("Price");
        System.out.println("-------");
        for(Shoes x : In_Stock){
            System.out.println(x.get_name() + ": " +x.get_price());
        }
        for(Upper_wear x : In_Stock_upper){
            System.out.println(x.get_name() + ": " + x.get_price());
        }


    }

我想要的是更像这样的东西：

public class Want_run
{
    public static void main(String[]args){
        Clothing Tennis_shoes_01 = new Shoes("Canvas", 0, "yes", 10, "red and white", 0,0.5,2.5, 00001, 750.99,"Tenny shoey");
        //Not sure if this is possible to have a class that's different than the constructor but I am looking for it to come from clothing class with properties of Shoes.
        Clothing T_shirt_01 = new Upper_wear("Cotton", 0, "no", 0, 14, "yellow", 14.5, 15, "v-neck", "no", 00002, 990.50, "Yel-ow");
        //So I want all properties to be in clothing but the ones that the childeren don't have I want to be just blank.ex. Upper_wear is blank on the shoe_laces. 
        Clothing[]In_Stock = {Tennis_shoes_01, T_shirt_01};
        //I really want everything to be just in one list to iterate through but I can't currently do that with multiple parents of my knowledge.
        for(Clothing x : In_Stock){
            System.out.println(x.get_name() + ": " + x.get_price());
        }
        //this way I have only one for loop for every item,and for parents that don't have 'price' I am hoping would just not print.
    }
}

所以我希望服装具有 'Upper_wear'、'Lower_wear' 和 'Shoes' 的所有属性，而不是 parent 具有服装的所有属性。这样特定于鞋子的属性，我希望在循环遍历特定于鞋子的方法时，其他两个 parent 为空。我不确定我正在寻找的东西是否有可能做到。如果您不明白我在寻找什么，很抱歉让您感到困惑。感谢您花时间阅读本文并帮助我。

Answer 1

您要做的是 class多态性的 ic 应用。你只需要澄清几个概念。

你的大 parent 将包含所有 children 共有的所有属性，例如项目 ID、名称、颜色、价格等。它还应该包含共同的函数，例如 print() 函数，这是您在 main 中需要的函数。

所有child人（包括parent人）都会在class人里面介绍自己的具体属性，比如hood/collar是鞋面，内里是夹克.他们还会覆盖（提供自己的实现）他们需要根据需要定制的功能。因此，在您的情况下，虽然 Clothing 有一个 print() 函数，但每个子 class 都有自己的实现，其中它将打印自己的所有属性，例如拉链数、鞋带数。

最后，在您的 main 中，您将有一个 Clothing 类型的列表，其中将包含对 object 所需所有类型的引用。 parent 可以指向 child 类型的 object。例如，

Clothing c = new Jacket(...);
c.print();    // This will call the print() of class Jacket, not Clothing

我建议阅读动态多态性。 This link 包含快速介绍和漂亮的示例。

如何在一个grandparentclass中拥有所有的parentclass而不获得grandparentclass的所有属性？

How to have all parent classes in one grandparent class without gaining all attributes of grandparent class?

java

polymorphism

bluej