同步计数器Semaphore

package com.lin.test;

import java.util.concurrent.Semaphore;

public class SemaphoreTest {

public static void main(String[] args) {

final Semaphore semaphore = new Semaphore(3);

for(int i=0;i<10;i++){
final int no = i;
Runnable thread = new Runnable() {
@Override
public void run() {
try {
System.out.println("客户端"+no+"连上了。。。");
semaphore.acquire();//获取接下来执行的许可
Thread.sleep(3000);//模拟服务器处理请求的时间
System.out.println("客户端"+no+"访问结束。。。");
} catch (Exception e) {

}
finally{
semaphore.release();//释放允许下一个线程访问
}
}
};
new Thread(thread).start();
}
}

}