import java.util.*; //这个例子不太好 //Flyweight interface Flyweight { void action(int arg); } //ConcreteFlyweight class FlyweightImpl implements Flyweight { public void action(int arg) { // TODO Auto-generated method stub System.out.println("参数值:" + arg); } } //FlyweightFactory class FlyweightFactory { private static Map flyweights = new HashMap(); public FlyweightFactory(String arg) { flyweights.put(arg, new FlyweightImpl()); } public static Flyweight getFlyweight(String key) { if (flyweights.get(key) == null) { flyweights.put(key, new FlyweightImpl()); } return (Flyweight)flyweights.get(key); } public static int getSize() { return flyweights.size(); } } //Test public class DS11_Flyweight{ public static void main(String[] args) { // TODO Auto-generated method stub Flyweight fly1 = FlyweightFactory.getFlyweight("a"); fly1.action(1); Flyweight fly2 = FlyweightFactory.getFlyweight("a"); System.out.println(fly1 == fly2); Flyweight fly3 = FlyweightFactory.getFlyweight("b"); fly3.action(2); Flyweight fly4 = FlyweightFactory.getFlyweight("c"); fly4.action(3); Flyweight fly5 = FlyweightFactory.getFlyweight("d"); fly4.action(4); System.out.println(FlyweightFactory.getSize()); } }