Пример полиморфизма

package ru.company.app;

import java.util.ArrayList;
import java.util.List;

interface IScreen {
    void draw(int x, int y);
    void put(int x, int y);
}

abstract class Figure implements IScreen {
    private int x;
    private int y;

    @Override
    public void put(int x, int y) {
        this.x = x;
        this.y = y;
    }
}

class Point extends Figure {
    @Override
    public void draw(int x, int y) {
        put(x, y);
        System.out.println(this.getClass().toString()+ " x=" + x + " y="+y);
    }
}

class Circle extends Figure/*Point*/ {
    private int radius;
    @Override
    public void draw(int x, int y) {
        put(x, y);
        System.out.println(this.getClass().toString()+ " x=" + x + " y="+y + " radius="+radius);
    }
}

public class Main {
    public static void main(String[] args) {
        Point point = new Point();
        point.draw(10, 10);

        Circle circle = new Circle();
        circle.draw(20, 20);

        List<Figure> figures = new ArrayList<>();

        figures.add(point);
        figures.add(circle);

        for (Figure curFig: figures) {
            curFig.draw(10, 10);
        }
    }
}