package locks;import java.util.Random;import java.util.concurrent.locks.Condition;import java.util.concurrent.locks.Lock;import java.util.concurrent.locks.ReentrantLock;public class AppOfficial {    /**     * BoundedBuffer 是一个定长100的集合，当集合中没有元素时，take方法需要等待，直到有元素时才返回元素     * 当其中的元素数达到最大值时，要等待直到元素被take之后才执行put的操作     * @author yukaizhao     *     */    static class BoundedBuffer {        final Lock lock = new ReentrantLock();        final Condition notFull = lock.newCondition();        final Condition notEmpty = lock.newCondition();        final Object[] items = new Object[100];        int putptr, takeptr, count;        public void put(Object x) throws InterruptedException {            System .out.println("put wait lock");            lock.lock();            System.out.println("put get lock");            try {                while (count == items.length) {                    System.out.println("buffer full, please wait");                    notFull.await();                }                                    items[putptr] = x;                if (++putptr == items.length)                    putptr = 0;                ++count;                notEmpty.signal();            } finally {                lock.unlock();            }        }        public Object take() throws InterruptedException {            System.out.println("take wait lock");            lock.lock();            System.out.println("take get lock");            try {                while (count == 0) {                    System.out.println("no elements, please wait");                    notEmpty.await();                }                Object x = items[takeptr];                if (++takeptr == items.length)                    takeptr = 0;                --count;                notFull.signal();                return x;            } finally {                lock.unlock();            }        }    }        public static void main(String[] args) {        final BoundedBuffer boundedBuffer = new BoundedBuffer();                Thread t1 = new Thread(new Runnable() {            @Override            public void run() {                System.out.println("t1 run");                for (int i=0;i<1000;i++) {                    try {                        System.out.println("putting..");                        boundedBuffer.put(Integer.valueOf(i));                    } catch (InterruptedException e) {                        e.printStackTrace();                    }                }            }                    }) ;                Thread t2 = new Thread(new Runnable() {            @Override            public void run() {                for (int i=0;i<1000;i++) {                    try {                        Object val = boundedBuffer.take();                        System.out.println(val);                    } catch (InterruptedException e) {                        e.printStackTrace();                    }                }            }                    }) ;                t1.start();        t2.start();    }}