java - java变量的多态或改名

Question

我想根据用户的选择更改变量的名称。我知道它可以通过 Mab 来完成(不是很迷人)，但我认为它也可以通过多态来完成，至少是可以模拟它的东西。这很难解释，所以下面的代码可以更好地说明它。谢谢!

        public class Main {
            public static void main(String[] args) {
                GenericObject o;

                o = new Object1(10, 10);
                o.wh();
                System.out.println(o.w); // Output: 3 (ok)
                System.out.println(o.h); // Output: 10 (ok)

                o = new Object2(10, 10);
                o.wh();
                System.out.println(o.w); // Output: 7 (ok)
                System.out.println(o.h); // Output: 4 (ok)

                String inputFromUser = "1";
                o = new Object + inputFromUser + (10, 10); /*I know that is an absurd, just to illustrate...
if polymorphism can solve this problem, I thik it's the best option. So how use it here?
I don't wanna use ifs or switchs, I will use more than 300 classes*/
                o.wh();
                System.out.println(o.w); // Output: 3 (that's what I wanna obtain)
                System.out.println(o.h); // Output: 10 (that's what I wanna obtain)
            }
        }
        abstract class GenericObject {
            int w, h, x, y;
            GenericObject (int x, int y) {
                this.x = x;
                this.y = y;
            }
            public abstract void wh();
        }
        class Object1 extends GenericObject{
            Object1 (int x, int y) {
                super(x, y);
            }
            @Override
            public void wh () {
                w = 3;
                h = 10;
            }
        }
        class Object2 extends GenericObject{
            Object2 (int x, int y) {
                super(x, y);
            }
            @Override
            public void wh () {
                w = 7;
                h = 4;
            }
        }

Answer 1

希望下面的代码对您有所帮助。

            HashMap<String, GenericObject > allTypes = new HashMap<>();
            allTypes.put("1", new Object1(10, 10));
            allTypes.put("2", new Object2(10, 10));

            String inputFromUser = "1";
            GenericObject o = allTypes.get(inputFromUser);
            o.wh();
            System.out.println(o.w); // Output: 3 
            System.out.println(o.h); // Output: 10