Java模拟并发

=========================one=============================

public class Bingfa {

public static void main(String[] args) throws InterruptedException {

// 锁住所有线程，等待并发执行

final CountDownLatch begin = new CountDownLatch(1);

final ExecutorService exec = Executors.newFixedThreadPool(10);

for (int index = 0; index < 100; index++)

{

final int NO = index + 1;

Runnable run = new Runnable()

{

public void run() {

try {

// 等待，所有一起执行

begin.await();

//*****执行程序去********//

　　　　　　　　　　？？？？？？？？？？？？

//*****执行程序去********//

} catch (InterruptedException e)

{

e.printStackTrace();

}

finally {

}

}

};

exec.submit(run);

}

System.out.println("开始执行");

// begin减一，开始并发执行

begin.countDown();

//关闭执行

exec.shutdown();

}

}

==========================two==================================

public class CountdownLatchTest {

public static void main(String[] args) {

ExecutorService service = Executors.newCachedThreadPool(); //创建一个线程池

final CountDownLatch cdOrder = new CountDownLatch(1);//构造方法参数指定计数的次数

final CountDownLatch cdAnswer = new CountDownLatch(3);//构造方法参数指定计数的次数

for(int i=0;i<3;i++){

Runnable runnable = new Runnable(){

public void run(){

try {

System.out.println("线程" + Thread.currentThread().getName() +

"正准备接受命令");

cdOrder.await(); //战士们都处于等待命令状态

System.out.println("线程" + Thread.currentThread().getName() +

"已接受命令");

Thread.sleep((long)(Math.random()*10000));

System.out.println("线程" + Thread.currentThread().getName() +

"回应命令处理结果");

} catch (Exception e) {

e.printStackTrace();

} finally {

cdAnswer.countDown(); //任务执行完毕，返回给指挥官，cdAnswer减1。

}

}

};

service.execute(runnable);//为线程池添加任务

}

try {

Thread.sleep((long)(Math.random()*10000));

System.out.println("线程" + Thread.currentThread().getName() +

"即将发布命令");

cdOrder.countDown(); //发送命令，cdOrder减1，处于等待的战士们停止等待转去执行任务。

System.out.println("线程" + Thread.currentThread().getName() +

"已发送命令，正在等待结果");

cdAnswer.await(); //命令发送后指挥官处于等待状态，一旦cdAnswer为0时停止等待继续往下执行

System.out.println("线程" + Thread.currentThread().getName() +

"已收到所有响应结果");

} catch (Exception e) {

e.printStackTrace();

} finally {

}

service.shutdown(); //任务结束，停止线程池的所有线程

}

}

转载：http://blog.csdn.net/zhao9tian/article/details/40346899