享元模式的特点：

        享元模式可以共享相同的对象，避免创建过多的对象实例，从而节省内存资源

使用场景：

        常用于需要创建大量相似的对象的情况

享元接口类

public interface Flyweight { void operate(String extrinsicState); }

享元实现类

public class ConcreteFlyweight implements Flyweight {@Overridepublic void operate(String extrinsicState) {System.out.println("固有状态： " + intrinsicState);System.out.println("外部状态 " + extrinsicState);}
}

享元工厂类

public class FlyweightFactory {private Map<String, Flyweight> flyweights;public Flyweight getFlyweight(String intrinsicState) {if (flyweights.containsKey(intrinsicState)) {return flyweights.get(intrinsicState);} else {Flyweight flyweight = new ConcreteFlyweight(intrinsicState);flyweights.put(intrinsicState, flyweight);return flyweight;}}
}

演示类

public class Demo {public static void main(String[] args) {FlyweightFactory factory = new FlyweightFactory();//保存固有状态Flyweight flyweight1 = factory.getFlyweight("SharedState");Flyweight flyweight2 = factory.getFlyweight("SharedState");//处理外部状态flyweight1.operate("ExtrinsicState1");flyweight2.operate("ExtrinsicState2");}
}

演示结果

为了使演示代码更简洁，我移除了构造方法和set/get方法