前置文章为https://segmentfault.com/a/11...，如果不了解AQS的基本lock和unlock实现机制，建议先看一下这个文章。

CondITion类似于wait和notify,notifyAll，常用于实现生产者消费者。以下代码是一个用ReentrantLock的condition做的一个生产者消费者例子。

import java.util.concurrent.locks.Condition; import java.util.concurrent.locks.Lock; import java.util.concurrent.locks.ReentrantLock;  class BoundedBuffer {     final Lock lock = new ReentrantLock();     // condition 依赖于 lock 来产生     final Condition notFull = lock.newCondition();     final Condition notEmpty = lock.newCondition();      final Object[] items = new Object[100];     int putptr, takeptr, count;      // 生产     public void put(Object x) throws InterruptedException {         lock.lock();         try {             while (count == items.length)                 notFull.await();  // 队列已满，等待，直到 not full 才能继续生产             items[putptr] = x;             if (++putptr == items.length) putptr = 0;             ++count;             notEmpty.signal(); // 生产成功，队列已经 not empty 了，发个通知出去         } finally {             lock.unlock();         }     }      // 消费     public Object take() throws InterruptedException {         lock.lock();         try {             while (count == 0)                 notEmpty.await(); // 队列为空，等待，直到队列 not empty，才能继续消费             Object x = items[takeptr];             if (++takeptr == items.length) takeptr = 0;             --count;             notFull.signal(); // 被我消费掉一个，队列 not full 了，发个通知出去             return x;         } finally {             lock.unlock();         }     } }