类似于synchronized中的wait和notify方法，
在更轻量级的lock锁中，同样有着condition来实现消息通信，本文先介绍基本用法。
condition的await和signal方法同样也必须在lock块里面。
package service; import java.util.concurrent.locks.Condition; import java.util.concurrent.locks.Lock; import java.util.concurrent.locks.ReentrantLock; public class MyService { private Lock lock = new ReentrantLock(); public Condition condition = lock.newCondition(); public void await() { try { lock.lock(); System.out.println(" await时间为" + System.currentTimeMillis()); condition.await(); } catch (InterruptedException e) { e.printStackTrace(); } finally { lock.unlock(); } } public void signal() { try { lock.lock(); System.out.println("signal时间为" + System.currentTimeMillis()); condition.signal(); } finally { lock.unlock(); } } }线程包装类：
package extthread; import service.MyService; public class ThreadA extends Thread { private MyService service; public ThreadA(MyService service) { super(); this.service = service; } @Override public void run() { service.await(); } }
执行类：
package test; import service.MyService; import extthread.ThreadA; public class Run { public static void main(String[] args) throws InterruptedException { MyService service = new MyService(); ThreadA a = new ThreadA(service); a.start(); Thread.sleep(3000); service.signal(); } }
