public class ThreadTest3 {
private static Lock lock = new ReentrantLock();
private static Condition subThreadCondition = lock.newCondition();
//private static Condition subThreadCondition2 = lock.newCondition();
private static boolean bBhouldSubThread = false;
public static void main(String[] args) {
ExecutorService threadPool = Executors.newFixedThreadPool(2);
threadPool.execute(new Runnable() {
public void run() {
for (int i = 0; i < 5; i++) {
lock.lock();
try {
if (!bBhouldSubThread){//不应该应该执行子线程
System.out.println("我在前面--我开始执行了"+bBhouldSubThread);
subThreadCondition.await();
System.out.println("我开始执行了"+bBhouldSubThread);
}
for (int j = 0; j < 2; j++) {
System.out.println("我开始执行了2");
System.out.println(Thread.currentThread().getName()
+ ",j=" + j);
}
bBhouldSubThread = false;
subThreadCondition.signal();
} catch (Exception e) {
} finally {
lock.unlock();
}
}
}
});
threadPool.shutdown();//在完成已提交的任务后关闭服务,不再接受新任务
for (int i = 0; i < 5; i++) {
System.out.println("i am starting----1");
lock.lock();
try {
if (bBhouldSubThread){//应该执行子线程
System.out.println("i am starting----2"+bBhouldSubThread);
subThreadCondition.await();
}
for (int j = 0; j < 10; j++) {
System.out.println(Thread.currentThread().getName() + ",i="
+ j);
}
bBhouldSubThread = true;
subThreadCondition.signal();
} catch (Exception e) {
} finally {
System.out.println("i am starting----3");
lock.unlock();
}
}
}
}
程序是主线程和子线程轮番打印数字
关于Condition的理解:Condition的功能类似于在传统的线程技术中的,Object.wait()和Object.notify()的功能
关于Lock的理解:Lock比传统线程模型中的Synchronied方式更加面向对象,与生活中的锁类似,锁本身也应该是一个对象.两个线程执行的代码段要实现同步互斥的效果,它们必须用同一个Lock对象,即程序中的lock,锁是在代表要操作的资源的类的内部方法中,而不是线程代码中.