设计模式享元模式

类图

 

 

源码

package weight;

/**
 * 坐标类：外部状态类
 * @author fly
 *
 */
class Coordinates {
    
    private int x;
    private int y;
    
    public Coordinates(int x,int y) {
        // TODO Auto-generated constructor stub
        this.x = x;
        this.y = y;
    }
 
    public int getX() {
        return x;
    }
 
    public void setX(int x) {
        this.x = x;
    }
 
    public int getY() {
        return y;
    }
 
    public void setY(int y) {
        this.y = y;
    }
    
}
（2）    抽象享元类
package weight;

/**
 * 围棋棋子类：抽象享元类
 * @author fly
 *
 */
abstract class IgoChessman {
    
    public abstract String getColor();
    public void locate(Coordinates coord){
        System.out.println("棋子颜色："+this.getColor()+",棋子位置："+coord.getX()+","+coord.getY());
    }
}
/**
 * 黑色棋子类：具体享元类
 * @author fly
 *
 */
class BlackIgoChessman extends IgoChessman{
 
    @Override
    public String getColor() {
        // TODO Auto-generated method stub
        return "黑色";
    }
 
}
/**
 * 白色棋子类：具体享元类
 * @author fly
 *
 */
class WhiteIgoChessman extends IgoChessman{
 
    @Override
    public String getColor() {
        // TODO Auto-generated method stub
        return "白色";
    }
 
}

（3）    享元工厂类
package weight;

import java.util.Hashtable;

/**
 * 围棋棋子工厂类：享元工厂类
 * @author fly
 *
 */
public class IgoChessmanFactory {
    
    private static IgoChessmanFactory instance = new IgoChessmanFactory();
    private static Hashtable ht;
    
    public IgoChessmanFactory() {
        // TODO Auto-generated constructor stub
        ht = new Hashtable();
        IgoChessman black,white;
        black = new BlackIgoChessman();
        ht.put("b", black);
        white = new WhiteIgoChessman();
        ht.put("w", white);
    }
    
    public static IgoChessmanFactory getInstance(){
        return instance;
    }
    
    public static IgoChessman getIgoChessman(String color){
        return (IgoChessman)ht.get(color);
    }
}
（4）    测试类
package weight;

/**
 * 客户端测试类
 * @author fly
 *
 */
public class Client {
    
    public static void main(String[] args) {
        IgoChessman black1,black2,black3,white1,white2;
        IgoChessmanFactory factory;
        factory = IgoChessmanFactory.getInstance();
        black1 = factory.getIgoChessman("b");
        black2 = factory.getIgoChessman("b");
        black3 = factory.getIgoChessman("b");
        System.out.println("判断两颗黑棋是否相同："+(black1==black2));
        white1 = factory.getIgoChessman("w");
        white2 = factory.getIgoChessman("w");
        System.out.println("判断两颗白棋是否相同："+(white1==white2));
        black1.locate(new Coordinates(1, 2));
        black2.locate(new Coordinates(3, 4));
        black3.locate(new Coordinates(1, 3));
        white1.locate(new Coordinates(2, 5));
        white2.locate(new Coordinates(2, 4));
    }
}

 

测试截图