import java.util.concurrent.Exchanger;/** * 案例：服务员向原有空杯中不断倒水，消费者不断从原有装满水的杯中喝水。  * 当服务员倒满水和消费者喝完水时，两个杯子进行交换。一直这样周而复始。 *  * @author Administrator *  */public class TestExchanger {	static Exchanger
    
      exchanger = new Exchanger
     
      ();	static Cup emptyCup = new Cup(0);	static Cup fullCup = new Cup(100);	public static void main(String[] args) {		new Thread(new Waiter(3)).start();		new Thread(new Customer(6)).start();	}	/**	 * 服务员	 * 	 * @author Administrator	 * 	 */	static class Waiter implements Runnable {		int addSpeed = 1;		public Waiter(int addSpeed) {			this.addSpeed = addSpeed;		}		@Override		public void run() {			while (emptyCup != null) {				// 如果发现杯子中的水没有满，则往杯中加水。				try {					if (emptyCup.isFull()) {// 当emptyCup为装满水时并且fullCup为被喝完水时，进行交换。						// 当Waiter把杯子水装满后，与Customer交换杯子。						// exchange(emptyCup)中参数的emptyCup是waiter装满水后的，把装满水后的emptyCup参数传递给Cutomer线程。						// 并且返回Cutomer线程中fullCup给Waiter的emptyCup，这样就达到了交换效果。						emptyCup = exchanger.exchange(emptyCup);						System.out.println("Waiter: " + emptyCup.capacity);					} else {						emptyCup.addWaterToCup(3);						System.out.println("Waiter add " + addSpeed								+ " and current capacity is "								+ emptyCup.capacity);						Thread.sleep((long) (Math								.max(500, Math.random() * 2000)));					}				} catch (InterruptedException e) {					e.printStackTrace();				}			}		}	}	/**	 * 消费者	 * 	 * @author Administrator	 * 	 */	static class Customer implements Runnable {		int drinkSpeed = 1;		public Customer(int drinkSpeed) {			this.drinkSpeed = drinkSpeed;		}		@Override		public void run() {			while (fullCup != null) {				// 如果发现杯子中的水没有满，则往杯中加水。				try {					if (fullCup.isEmpty()) {						// 水满后则交换子中的水						fullCup = exchanger.exchange(fullCup);						System.out.println("Customer: " + fullCup.capacity);					} else {						fullCup.drinkFormCup(drinkSpeed);						System.out.println("Customer drinked " + drinkSpeed								+ " and current capacity is "								+ fullCup.capacity);						Thread.sleep((long) (Math								.max(500, Math.random() * 2000)));					}				} catch (InterruptedException e) {					e.printStackTrace();				}			}		}	}	static class Cup {		private int capacity = 0;		public Cup(int capacity) {			this.capacity = capacity;		}		public void addWaterToCup(int i) {			capacity += i;			capacity = capacity > 100 ? 100 : capacity;		}		public void drinkFormCup(int i) {			capacity -= i;			capacity = capacity < 0 ? 0 : capacity;		}		public boolean isFull() {			return capacity == 100 ? true : false;		}		public boolean isEmpty() {			return capacity == 0 ? true : false;		}	}}