设计模式 | 享元模式（Flyweight）

package designpattern.flyweight;

public interface Chessman {
    abstract void position(String position);
}

package designpattern.flyweight;

public class ConcreteChessman implements Chessman {
    String color;

    public ConcreteChessman(String color) {
        this.color = color;
    }

    @Override
    public void position(String position) {
        System.out.println(color + "棋下在：" + position);
    }

}

package designpattern.flyweight;

import java.util.HashMap;
import java.util.Map;


public class ChessmanFactory {
    Map<String, Chessman> map = new HashMap<>();

    public Chessman getChessman(String color) {
        if (map.containsKey(color)) {
            return map.get(color);
        } else {
            Chessman chessman = new ConcreteChessman(color);
            map.put(color, chessman);
            return chessman;
        }
    }
}

package designpattern.flyweight;

public class Client {
    public static void main(String[] args) {
        ChessmanFactory factory=new ChessmanFactory();
        Chessman cc1= factory.getChessman("黑");
        cc1.position("右上星位");
        
        Chessman cc2= factory.getChessman("白");
        cc2.position("天元");
        
        Chessman cc3= factory.getChessman("黑");
        cc3.position("右上目外");
    }
}

黑棋下在：右上星位
白棋下在：天元
黑棋下在：右上目外