Semaphore.acquire():Acquires a permit from this semaphore, blocking until one is available
与Executors.newFixedThreadPool( 2 )作用相似
CyclicBarrier.await(): Waits until all parties have invoked await on this barrier.
CountDownLatch.await(): Causes the current thread to wait until the latch has counted down to zero
/** * CountDownLatch.await(): Causes the current thread to wait until the latch has counted down to zero, * unless the thread is interrupted. * @author timeriver.wang * @date 2014-03-10 10:39:10 AM */ public class CountdownLatchTest { public static void main( String[] args ) { ExecutorService service = Executors.newCachedThreadPool(); final CountDownLatch cdOrder = new CountDownLatch( 1 ); final CountDownLatch cdAnswer = new CountDownLatch( 3 ); for ( int i = 0; i < 3; i++ ) { Runnable runnable = new Runnable() { public void run() { System.out.println( "线程" + Thread.currentThread().getName() + "正准备接受命令" ); try { cdOrder.await(); System.out.println( "线程" + Thread.currentThread().getName() + "已接受命令" ); Thread.sleep( (long) ( 1000 ) ); } catch ( InterruptedException e ) { e.printStackTrace(); } System.out.println( "线程" + Thread.currentThread().getName() + "回应命令处理结果" ); cdAnswer.countDown(); } }; service.execute( runnable ); } service.shutdown(); try { // make sure thread all have start. can using t.join() Thread.sleep( (long) ( 1000 ) ); System.out.println( "线程" + Thread.currentThread().getName() + "即将发布命令" ); cdOrder.countDown(); System.out.println( "线程" + Thread.currentThread().getName() + "已发送命令,正在等待结果" ); cdAnswer.await(); System.out.println( "线程" + Thread.currentThread().getName() + "已收到所有响应结果" ); } catch ( Exception e ) { e.printStackTrace(); } } }