public interface ICake {String getName();
}public class RealCake implements ICake{public RealCake(){try {//造蛋糕好费时间的Thread.sleep(2000);} catch (InterruptedException e) {e.printStackTrace();}}public String getName() {return "最大最好吃的蛋糕";}
}
public class CakeTicket implements ICake {private RealCake cake;public synchronized String getName() {while(cake==null){try {//还没有做好，等待...
                wait();} catch (InterruptedException e) {e.printStackTrace();}}return cake.getName();}public synchronized void setCake(RealCake cake) {this.cake = cake;//做好了，可以取蛋糕了
        notifyAll();}}public class CakeShop {//获取蛋糕的方法public static ICake getCake(){//构造一个虚拟数据返回给客户，这只是个虚拟的结果，相当给了客户一张取结果的卡，但是客户最好不要//急着取结果，因为结果数据一般需要一定时间构造，客户最好去干点别的，过一会再来取final CakeTicket cake = new CakeTicket();//使用一个线程去构造真实的数据，为何要用线程，因为这个资源构造比较费时new Thread(new Runnable(){public void run() {RealCake realData = new RealCake();cake.setCake(realData);}}).start();return cake;}
}public class Me {public static void main(String[] args) {ICake cake = CakeShop.getCake();System.out.println("买花去喽");//dosomethingSystem.out.println("蛋糕的名字："+cake.getName());}
}

public static Future<RealCake> getCake(){ExecutorService threadpool = Executors.newCachedThreadPool();Future<RealCake> futureData = threadpool.submit(new Callable<RealCake>() {public RealCake call() throws Exception {RealCake realCake = new RealCake();return realCake;}});return futureData;}
public static void main(String[] args) throws InterruptedException, ExecutionException {Future<RealCake> cake = CakeShop4Future.getCake();System.out.println("买花去喽");//dosomethingSystem.out.println("蛋糕的名字："+cake.get().getName());}