代码示例：java.util.concurrent.locks.Lock
import java.util.concurrent.locks.Lock;import java.util.concurrent.locks.ReentrantLock;/** * @author kent 2013-3-11上午11:55:28 */public class PlayLock implements Runnable { private Bean bean; public PlayLock(Bean bean) { super(); this.bean = bean; } public void run() { for (int j = 0; j < 100; j++) { bean.increment(); } } private static final class Bean { private int i = 0; private Lock lockObject = new ReentrantLock(); //如果是 new ReentrantLock(true)则代表锁是“公平”的，即先求锁者先得锁，避免“饿死” public void increment() { try { lockObject.lock(); //加锁 doIncrement(); } finally { lockObject.unlock(); //释放锁，要放在finally块里 } } private void doIncrement() { int k = i; k = k + 1; doSleep(); i = k; System.out.println(Thread.currentThread().getName() + ": i = " + i); } private void doSleep() { try { Thread.sleep(100); } catch (InterruptedException e) { throw new RuntimeException(e); } } } public static void main(String[] args) { Bean bean = new Bean(); Thread t1 = new Thread(new PlayLock(bean)); Thread t2 = new Thread(new PlayLock(bean)); t1.start(); t2.start(); }}