java.util.concurrent.CountDownLatch

java.util.concurrent.CountDownLatch

一个同步辅助类，在完成一组正在其他线程中执行的操作之前，它允许一个或多个线程一直等待。

主要方法

 public CountDownLatch(int count);

 public void countDown();

 public void await() throws
InterruptedException

 

构造方法参数指定了计数的次数

countDown方法，当前线程调用此方法，则计数减一

awaint方法，调用此方法会一直阻塞当前线程，直到计时器的值为0

public class Recipes_NoLock {
public static void main(String[] args) {
final CountDownLatch down = new CountDownLatch(1);
for(int i=0;i<10;i++){
new Thread(new Runnable() {

public void run() {
try {
down.await();
} catch (InterruptedException e) {
}
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss|SSS");
String no = sdf.format(new Date());
System.out.println("订单号："+no);
}
}).start();;
}
down.countDown();
}

}

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.concurrent.CountDownLatch;

import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.framework.recipes.locks.InterProcessMutex;
import org.apache.curator.retry.ExponentialBackoffRetry;

public class Recipes_Lock {
static String path = "/curator_recipes_lock_path";

static CuratorFramework client = CuratorFrameworkFactory.builder()
.connectString("172.18.1.34:2181")
.sessionTimeoutMs(5000)
.retryPolicy(new ExponentialBackoffRetry(1000, 3))
.build();

public static void main(String[] args) {
client.start();
final InterProcessMutex lock = new InterProcessMutex(client, path);
final CountDownLatch down = new CountDownLatch(1);
for(int i=0;i<10;i++){
new Thread(new Runnable() {

public void run() {
try {
down.await();
lock.acquire();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss|SSS");
String no = sdf.format(new Date());
System.out.println("订单号："+no);

try {
lock.release();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}).start();;
}
down.countDown();
}

}