享元模式——java实现 - 戈瑾

问题描述：

设计一个围棋软件，在系统中只存在一个白棋对象和一个黑棋对象，但是它们可以在棋盘的不同位置显示多次。

类图：

Java代码：

  1 //Coordinates.java
  2 package shiyan13;
  3 //外部状态类——坐标类
  4 class Coordinates {
  5     
  6     private int x;
  7     private int y;
  8     
  9     public Coordinates(int x,int y) {
 10         // TODO Auto-generated constructor stub
 11         this.x = x;
 12         this.y = y;
 13     }
 14  
 15     public int getX() {
 16         return x;
 17     }
 18  
 19     public void setX(int x) {
 20         this.x = x;
 21     }
 22  
 23     public int getY() {
 24         return y;
 25     }
 26  
 27     public void setY(int y) {
 28         this.y = y;
 29     }
 30 }
 31 //Chess.java
 32 package shiyan13;
 33 
 34 abstract class Chess {
 35     public abstract String getColor();
 36     public void locate(Coordinates co) {
 37         System.out.println(this.getColor()+"棋的位置："+co.getX()+","+co.getY());
 38     }
 39 }
 40 //ChessFactory.java
 41 package shiyan13;
 42 
 43 import java.util.Hashtable;
 44 
 45 public class ChessFactory {
 46     private static ChessFactory instance=new ChessFactory();
 47     private static Hashtable ht;
 48     public ChessFactory() {
 49         ht=new Hashtable();
 50         Chess black,white;
 51         black=new BlackChess();
 52         ht.put("b", black);
 53         white=new WhiteChess();
 54         ht.put("w", white);
 55     }
 56     public static ChessFactory getInstance() {
 57         return instance;
 58     }
 59     public static Chess getChess(String color) {
 60         return (Chess)ht.get(color)
 61 ;    }
 62 }
 63 //BlackChess.java
 64 package shiyan13;
 65 public class BlackChess extends Chess{
 66 
 67     @Override
 68     public String getColor() {
 69         // TODO 自动生成的方法存根
 70         return "黑";
 71     }
 72     
 73 }
 74 //WhiteChess.java
 75 package shiyan13;
 76 
 77 public class WhiteChess extends Chess{
 78 
 79     @Override
 80     public String getColor() {
 81         // TODO 自动生成的方法存根
 82         return "白";
 83     }
 84 
 85 }
 86 //Client.java
 87 package shiyan13;
 88 
 89 public class Client {
 90     
 91     public static void main(String[] args) {
 92         Chess black1,black2,black3,white1,white2;
 93         ChessFactory factory;
 94         factory = ChessFactory.getInstance();
 95         black1 = ChessFactory.getChess("b");
 96         black2 = ChessFactory.getChess("b");
 97         black3 = ChessFactory.getChess("b");
 98         white1 = ChessFactory.getChess("w");
 99         white2 = ChessFactory.getChess("w");
100         black1.locate(new Coordinates(5, 5));
101         black2.locate(new Coordinates(-3, 4));
102         black3.locate(new Coordinates(3, 1));
103         white1.locate(new Coordinates(-1, 5));
104         white2.locate(new Coordinates(2, 4));
105     }
106 }

运行结果：

posted on 2021-10-24 22:35 戈瑾阅读(179) 评论(0) 收藏举报

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