Блинов. Глава 4. Вариант А. 5 (*). Создать объект класса Планета, используя классы Материк, Океан, Остров. Методы: вывести на консоль название материка, планеты, количество материков.

Continent.java

public class Continent {
    private String name;

    public Continent(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }
}

Island.java

public class Island {
    private String name;

    public Island(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }
}

Ocean.java

public class Ocean {
    private String name;

    public Ocean(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }
}

Planet.java

public class Planet {
    private String name;

    private List<Ocean> oceanList = new ArrayList<>();
    private List<Continent> continentList = new ArrayList<>();
    private List<Island> islandList = new ArrayList<>();

    public Planet(String name) {
        this.name = name;
    }

    public void addOcean(Ocean ocean) {
        oceanList.add(ocean);
    }

    public void addContinent(Continent continent) {
        continentList.add(continent);
    }

    public void addIsland(Island island) {
        islandList.add(island);
    }

    public String getName() {
        return name;
    }

    public List<Ocean> getOceanList() {
        return oceanList;
    }

    public List<Continent> getContinentList() {
        return continentList;
    }

    public List<Island> getIslandList() {
        return islandList;
    }
}

PlanetRunner.java

public class PlanetRunner {
    public static void main(String[] args) {
        Island island = new Island("Barbados");

        Planet planet = new Planet("Earth");

        planet.addContinent(new Continent("Eurasia"));
        planet.addContinent(new Continent("Africa"));

        planet.addOcean(new Ocean("Atlantic"));
        planet.addOcean(new Ocean("Pacific"));

        planet.addIsland(new Island("Barbados"));

        System.out.println("Planet name: "+planet.getName());
        System.out.println("Continent name: "+getFirstContinentName(planet.getContinentList()));
        System.out.println("Count continents:" + planet.getContinentList().size());
    }

    public static String getFirstContinentName(List<Continent> continentList) {
        String result = null;
        for (Continent continent: continentList) {
            result = continent.getName();
        }

        return result;
    }
}