设计模式之享元模式

享元模式：运用共享技术有效地支持大量细粒度的对象。

 

public abstract class Flyweight {
    public abstract void method(int stamp);
}


public class ConcreteFlyweight extends Flyweight {
    @Override
    public void method(int stamp) {
        System.out.println("具体的Flyweight:" + stamp);
    }
}

public class UnsharedFlyweight extends Flyweight{
    @Override
    public void method(int stamp) {
        System.out.println("非共享的具体Flyweight:"+stamp);
    }
}

 

public class FlyweightFactory {
    private HashMap flyweights = new HashMap();

    public FlyweightFactory() {
        flyweights.put("A", new ConcreteFlyweight());
        flyweights.put("B", new ConcreteFlyweight());
    }

    public Flyweight getFlyweight(String key) {
        return (Flyweight) flyweights.get(key);
    }
}

 

public class FlyweightDemo {
    public static void main(String[] args) {
        int stamp = 10;
        FlyweightFactory factory = new FlyweightFactory();
        Flyweight A = factory.getFlyweight("A");
        A.method(stamp--);
        Flyweight B = factory.getFlyweight("B");
        B.method(stamp--);

        Flyweight unsharedFlyweight = new UnsharedFlyweight();
        unsharedFlyweight.method(stamp--);
    }
}