java - 对卡片对象进行排序

Question

我正在创建一个简单的纸牌游戏，我希望能够对 ArrayList<Card> 进行排序以便玩家的手牌更容易阅读。现在我有:

卡片类别:

public class Card implements Comparable {

public enum Suits {
    SPADES,
    CLUBS,
    HEARTS,
    DIAMONDS
}

public enum Values {
    TWO,
    THREE,
    FOUR,
    FIVE,
    SIX,
    SEVEN,
    EIGHT,
    NINE,
    TEN,
    JACK,
    QUEEN,
    KING,
    ACE, 
}

private Suits suit;
private Values value;

public Card(final Values value, final Suits suit) {
    this.value = value;
    this.suit = suit;
}

public Values getValue() {
    return value;
}

public Suits getSuit() {
    return suit;
}

public void showCard() {
    value = getValue();
    suit = getSuit();

    System.out.println(value + " of " + suit);
}

public int compareTo(final Object compareCard) {
    Card compareToCard = (Card) compareCard;
    Suits thisSuit = this.suit;
    Values thisValue = this.value;

    if (thisSuit.ordinal() == compareToCard.getSuit().ordinal() &&
        thisValue.ordinal() == compareToCard.getValue().ordinal()) {
        return 0;
    }
    else if (thisSuit.ordinal() == compareToCard.getSuit().ordinal()) {
        if (thisValue.ordinal() > compareToCard.getValue().ordinal()) {
            return 1;
        }
        else {
            return -1;
        }
    }
    else {
        return -1;
    }
}

}

我使用了ordinal值，因为我想对值 2-Ace 进行排序，只要它们组合在一起，花色的顺序并不重要。

然后我有一个ArrayList<Card>叫playerHand 。我正在尝试使用以下方法进行排序:

playerHand.sort();

当我编译此代码时，我收到一个错误:

error: method sort in interface List<E> cannot be applied to given types;
    playerHand.sort();
              ^
  required: Comparator<? super Card>
  found: no arguments
  reason: actual and formal argument lists differ in length
    where E is a type-variable:
    E extends Object declared in interface List

我不太确定我做错了什么。任何帮助将不胜感激!

Answer 1

您需要实现 Comparable 接口(interface)，如下所示:

public class Card implements Comparable<Card> {