polymorphism test

interface Soundable {

    void talk();
    String say();
}

interface Infoable { // Dat name...

    void showInfo();
}

interface Special extends Infoable, Soundable { }

//-------------------------------------------------------------------------------------------------

abstract class Animal implements Special {

    protected String sound;
    private int weight, height;

    protected Animal(int weight, int height) {
        this.weight = weight;
        this.height = height;
    }

    @Override
    public void talk() {
        System.out.println(this.sound);
    }

    @Override
    public String say() {
        return this.sound;
    }

    public int getWeight() {
        return this.weight;
    }

    void setWeight(int weight) {
        this.weight = weight;
    }

    public int getHeight() {
        return this.height;
    }

    public void setHeight(int height) {
        this.height = height;
    }

    @Override
    public void showInfo() {
        System.out.println("Weight: " + this.weight + ", Height: " + this.height + ". " + this.sound);
    }
}

class Dog extends Animal {

    Dog(int weight, int height) {
        super(weight, height);
        this.sound = "Hau!";
    }

    Dog() {

        super(0, 0);
        this.sound = "Hau!";
    }
}

class Cat extends Dog {

    Cat(int weight, int height) {
        super(weight, height);
        this.sound = "Miau!";
    }

    Cat() {

        super(0, 0);
        this.sound = "Miau!";
    }
}

//-------------------------------------------------------------------------------------------------

abstract class Vehicle implements Special {

    protected String brand, sound;
    private int power;

    protected Vehicle(int power) {
        this.power = power;
    }

    @Override
    public void talk() {
        System.out.println(this.sound);
    }

    @Override
    public String say() {
        return this.sound;
    }

    public int getPower() {
        return this.power;
    }

    public void setPower(int power) {
        this.power = power;
    }

    public void showInfo() {
        System.out.println("Brand: " + this.brand + ". Power: " + this.power + ". Sound: " + this.sound);
    }
}

class Car extends Vehicle {

    Car(int power) {
        super(power);
        super.sound = "Wrumm!";
    }

    Car() {
        super(0);
        super.sound = "Wrumm!";
    }
}

class Mercedes extends Car {

    Mercedes() {
        super(1500);
        super.sound = "Wrrr!";
    }
}

class Truck extends Vehicle {

    Truck(int power) {
        super(power);
        super.sound = "Hurrr!";
    }

    Truck() {
        super(0);
        super.sound = "Hurrr!";
    }
}

//-------------------------------------------------------------------------------------------------

public class Program {

    public static void main(String[] args) {

        Animal anim = new Cat(7, 20);

        anim.talk();
        anim.showInfo();

        anim = new Dog(15, 30);
        tell(anim);

        Vehicle veh = new Mercedes();
        tell(veh);

        veh = new Truck(4000);
        veh.talk();
        veh.showInfo();
    }

    public static void tell(Special spec) {
        spec.showInfo();
    }
}