Сортировка Java возражает в ArrayList

Код был бы намного чище, если бы вы использовали enum для представления ранга и набора вместо char.

Фактически, http://jcp.org/aboutJava/communityprocess/ jsr / tiger / enum.html имеет образец карты, иллюстрирующий использование Enum

Соответствующий бит кода скопирован ниже

public class Card implements Comparable, java.io.Serializable {
    public enum Rank { deuce, three, four, five, six, seven, eight, nine, ten,
                       jack, queen, king, ace }
    public enum Suit { clubs, diamonds, hearts, spades }

    private final Rank rank;
    private final Suit suit;

    private Card(Rank rank, Suit suit) {
        if (rank == null || suit == null)
            throw new NullPointerException(rank + ", " + suit);
        this.rank = rank;
        this.suit = suit;
    }

    public Rank rank() { return rank; }
    public Suit suit() { return suit; }

    public String toString() { return rank + " of " + suit; }

    public int compareTo(Object o) {
        Card c = (Card)o;
        int rankCompare = rank.compareTo(c.rank);
        return rankCompare != 0 ? rankCompare : suit.compareTo(c.suit);
    }

    private static List<Card> sortedDeck = new ArrayList<Card>(52);
    static {
        for (Iterator<Rank> i = Rank.VALUES.iterator(); i.hasNext(); ) {
            Rank rank = i.next();
            for (Iterator<Suit> j = Suit.VALUES.iterator(); j.hasNext(); )
                sortedDeck.add(new Card(rank, j.next()));
        }
    }

    // Returns a shuffled deck
    public static List<Card> newDeck() {
        List<Card> result = new ArrayList<Card>(sortedDeck);
        Collections.shuffle(result);
        return result;
    }
}

The Missing CompareTo code:

ArrayList<Card> aCardList = new ArrayList<Card>();

    Collections.sort(aCardList, new Comparator<Card>() {

        @Override
        public int compare(Card o1, Card o2) {
            if (o1.getRank() > o2.getRank())
                return -1;
            else if (o1.getRank() < o2.getRank())
                return 1;
            else
                return 0;
        }
    });

You can implement the Comparable interface such that the elements are compared by rank. Then Collections.sort will automatically do what you expect it to do.

Несколько более коротких методов

public String toString() {
   return "" + rank + suit;
}

public boolean isValidCard(){
    return "HSDC".indexOf(suit) != -1 &&
         "A23456789TJQK".indexOf(rand) != -1;
}

You could use thejava.util.Collections class to sort it. Particularly, two methods may come handy:

 static <T extends Comparable<? super T>>
 void sort(List<T> list)
      Sorts the specified list into ascending order, according to the natural ordering of its elements.

static <T> void sort(List<T> list, Comparator<? super T> c)
      Sorts the specified list according to the order induced by the specified comparator.

For the first method, you should make your Card class implement the Comparable interface.. For the second one, you should provide a custom comparator.

This is done in order for the collections framework to know how to compare your Card objects.

So, for example (first method), you would have this code:

In your card class

public Class Card implements Comparable{

//member and method definitions.

public int compareTo(Object o){
   //null checks && stuff missing.

   /*compares two cards based on rank.*/   
}

List<Card> cards = getAllCards();//returns an unsorted list implementation of Card objects.

java.util.Collections.sort(cards);