Deck.java

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collections;

public class Deck implements Serializable {
    private ArrayList<Card> cards;

    public Deck() {
        cards = new ArrayList<>();
        String[] suits = { "Hearts", "Diamonds", "Clubs", "Spades" };
        String[] ranks = { "2", "3", "4", "5", "6", "7", "8", "9", "10", "Jack", "Queen", "King", "Ace" };

        for (String suit : suits) {
            for (String rank : ranks) {
                cards.add(new Card(suit, rank));
            }
        }
        Collections.shuffle(cards);
    }

    public Card drawCard() {
        return cards.isEmpty() ? null : cards.remove(cards.size() - 1);
    }

    public void addCard(Card card) {
        cards.add(card);
    }

    public boolean isEmpty() {
        return cards.isEmpty();
    }
}