构造方法？？？

/**
* 创建扑克牌类
* @author
*
*/
public class Card implements Comparable<Card> {

   String num;
   String type;
   int rank; //rank代表等级，值越大，等级越高
   public Card(String type,String num,int rank) {
       this.num=num;
       this.type=type;
   this.rank=rank;
   }

   public Card() {

   }

   @Override
   public int compareTo(Card o) {

       return this.rank-o.rank; //比较rank值的大小
   }

}

/**
* 创建玩家类
* @author
*
*/
public class Player {

   String id;
   String name;
   List<Card>pCards; //用于存放玩家手中的牌

   public Player(String id,String name) {
       this.id=id;
       this.name=name;
   pCards=new ArrayList<Card>();
   }

}

/**
*
* @author
*
*/
public class CardDemo {

   List<Card>cards;
   List<Player>players;
   Player p1; //玩家
   Player p2;
   Card p1max; //玩家1最大的牌
Card p2max; //玩家2最大的牌
   Card p1min; //玩家1最小的牌
   Card p2min; //玩家2最小的牌
//创建扑克牌资源数组
   String[] CardType=new String[] {"方块","梅花","红桃","黑桃"}; //顺序不可调换，否则会影响大小比较的rank值
   String[] CardNum=new String[] {"2","3","4","5","6","7","8","9","10","J","Q","K","A"};

   public CardDemo() {

       this.cards=new ArrayList<Card>();
       this.players=new ArrayList<Player>();
   }

//创建扑克牌
   public void CreatCard() {

       System.out.println("---------创建扑克牌-----------");
       for(int i=0;i<13;i++) {
           for(int j=0;j<4;j++) {
           cards.add(new Card(CardType[j],CardNum[i],i*13+j));
           }
       }
       //遍历打印扑克牌资源
       System.out.println("--------扑克牌创建成功！----------");
       System.out.print("扑克牌为");
       for(Card c:cards) {
           System.out.print(c.type+c.num+",");
       }
       System.out.println("总共52张");
   }

//进行洗牌
   public void washCard() {
   System.out.println("----------开始洗牌--------------");
       Collections.shuffle(cards); //进行洗牌
   System.out.println("----------洗牌结束-------------");

   }

//创建两名玩家
public void creatPlayer() {
//键盘上输入两名玩家信息
   Scanner console=new Scanner(System.in);
System.out.println("请输入第一位玩家的ID和姓名：");
System.out.println("请输入ID");
   String id1=console.next();
   System.out.println("请输入姓名：");
   String name1=console.next();
   p1=new Player(id1, name1);
players.add(p1);
System.out.println("请输入第二位玩家的ID和姓名：");
System.out.println("请输入ID");
   String id2=console.next();
   System.out.println("请输入姓名：");
   String name2=console.next();
   p2=new Player(id2, name2);
players.add(p2);
   System.out.println("欢迎玩家："+p1.name);
   System.out.println("欢迎玩家："+p2.name);
}

//进行发牌
public void distrubiteCard() {
   System.out.println("---------开始发牌------------");
   p1.pCards.add(cards.get(0));
System.out.println("----玩家："+p1.name+"-拿牌------");
p2.pCards.add(cards.get(1));
System.out.println("----玩家："+p2.name+"-拿牌------");
p1.pCards.add(cards.get(2));
System.out.println("----玩家："+p1.name+"-拿牌------");
p2.pCards.add(cards.get(3));
System.out.println("----玩家："+p2.name+"-拿牌------");
   System.out.println("---------发牌结束------------");
}

//开始游戏
public void playGame() {
System.out.println("--------开始游戏-----------");
Collections.sort(p1.pCards); //对集合pCards进行排序
Collections.sort(p2.pCards);
p1max=p1.pCards.get(1);
p2max=p2.pCards.get(1);
System.out.println(p1.name+"最大的手牌："+p1max.type+p1max.num); //输出玩家1的最大手牌
System.out.println(p2.name+"最大的手牌："+p2max.type+p2max.num); //输出玩家2的最大手牌
if(p1max.rank>p2max.rank)
   { System.out.println("-----玩家"+p1.name+"获胜！-------"); }
else
   { System.out.println("-----玩家"+p2.name+"获胜！--------"); }
//输出玩家各自的手牌
System.out.println("-------玩家各自的手牌为：----------");
p1min=p1.pCards.get(0);
p2min=p2.pCards.get(0);
//打印两名玩家各自手上的两张牌
System.out.println(p1.name+":"+p1max.type+p1max.num+","+p1min.type+p1min.num);
System.out.println(p2.name+":"+p2max.type+p2max.num+","+p2min.type+p2min.num);
System.out.println("--------游戏结束-----------");
}

//主函数
   public static void main(String[] args) {
       CardDemo cd=new CardDemo();
cd.CreatCard(); //创建扑克牌
cd.washCard(); //洗牌
cd.creatPlayer(); //创建玩家
cd.distrubiteCard(); //进行发牌
cd.playGame(); //开始游戏
   }