生产者-消费者

class BoundedQueue<T>{
    private Object[] items;
    //添加的下标、删除的下标、数组当前数量
    private int addIndex,removeIndex,count;
    private Lock lock = new ReentrantLock();
    private Condition conditionProducer= lock.newCondition();
    private Condition conditionConsumer = lock.newCondition();
    public BoundedQueue(int size){
        items = new Object[size];
    }
    //添加一个元素，如果数组满，则添加线程进入等待状态，直到有“空位”
    public void add(T t) throws InterruptedException{
        lock.lock();
        try {
            while (count == items.length)
                conditionProducer.await();
            items[addIndex] = t;
            if (++addIndex == items.length)
                addIndex = 0;
            ++count;
            conditionConsumer.signal();
        }finally {
            lock.unlock();
        }
    }
    //由头部删除一个元素，如果数组为空，则删除线程进入等待状态，直到有新添加元素
    @SuppressWarnings("uncheck")//告诉编译器忽略 unchecked 警告信息，如使用List，ArrayList等未进行参数化产生的警告信息
                                //可以标注在类、字段、方法、参数、构造方法，以及局部变量上。
    public T remove() throws InterruptedException{
        lock.lock();
        try {
            while (count == 0)
                conditionConsumer.await();
            Object obj = items[removeIndex];
            if (++removeIndex == items.length)
                removeIndex = 0;
            --count;
            conditionProducer.signal();
            return (T)obj;
        }finally {
            lock.unlock();
        }
    }
}