Полиморфизм — Java: Основы ООП

// Device.java
public interface Device {
    void charge();
    void music();
    void video();
    void game();
}

// Smartphoneable.java
public interface Smartphoneable  extends Device {
    void call();
}

// Tabletable.java
public interface Tabletable extends Device {
}

// GalaxyNote.java
public class GalaxyNote implements Smartphoneable {
    @Override
    public void call() {
        System.out.println("[GALAXY_NOTE]: Call via SIM card");
    }

    @Override
    public void music() {
        System.out.println("[GALAXY_NOTE]: listen music via Yandex music");
    }

    @Override
    public void video() {
        System.out.println("[GALAXY_NOTE]: watch video via Rutube");
    }

    @Override
    public void game() {
        System.out.println("[GALAXY_NOTE]: play Mario game");
    }

    @Override
    public void charge() {
        System.out.println("[GALAXY_NOTE]: I will charge for 30 mins");
    }
}

// IPad.java
public class IPad implements Tabletable {

    @Override
    public void charge() {
        System.out.println("[IPAD]: I will charge for 1 hour");
    }

    @Override
    public void music() {
        System.out.println("[IPAD]: listen music via Apple music");
    }

    @Override
    public void video() {
        System.out.println("[IPAD]: watch video via Youtube");
    }

    @Override
    public void game() {
        System.out.println("[IPAD]: play game via Apple Arcade");
    }
}

// IPhone.java
public class IPhone implements Smartphoneable {
    @Override
    public void call() {
        System.out.println("[IPHONE]: Call via SIM card");
    }

    @Override
    public void music() {
        System.out.println("[IPHONE]: listen music via Yandex music");
    }

    @Override
    public void video() {
        System.out.println("[IPHONE]: watch video via Rutube");
    }

    @Override
    public void game() {
        System.out.println("[IPHONE]: play Mario game");
    }

    @Override
    public void charge() {
        System.out.println("[IPHONE]: I will charge for 30 mins");
    }
}

Пример использования подтипов:

// Example.java
public class Example {
    public static void main(String[] args) {
        Device ipad = new IPad();
        Device iphone = new IPhone();
        Device galaxyNote = new GalaxyNote();

        for (Device device: List.of(ipad, iphone, galaxyNote)) {
            device.game();
        }

        // 1
        List.of(ipad, iphone, galaxyNote).stream()
                .filter(device -> device instanceof Smartphoneable)
                .map(device -> (Smartphoneable) device)
                .forEach(Smartphoneable::call);

        //2
        for (Device device: List.of(ipad, iphone)) {
            if (device instanceof Smartphoneable) {
                ((Smartphoneable) device).call();
            }

        }

    }
}

Дополнительные материалы

1. Полиморфизм подтипов

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