JAvaスレッド同時countdownlatchクラス使用例

 
  
package com.yao; 
   
  
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
 
  
/**
 * CountDownLatch     ，       ，
 *                           。
 */
public class CountDownLatchTest {
 
  
 /**
  *         
  */
 public static class ComponentThread implements Runnable {
  //    
  CountDownLatch latch;
  //   ID
  int ID;
 
  
  //     
  public ComponentThread(CountDownLatch latch, int ID) {
   this.latch = latch;
   this.ID = ID;
  }
 
  
  public void run() {
   //      
   System.out.println("Initializing component " + ID);
   try {
    Thread.sleep(500 * ID);
   } catch (InterruptedException e) {
   }
   System.out.println("Component " + ID + " initialized!");
   //      
   latch.countDown();
  }
 }
 
  
 /**
  *      
  */
 public static void startServer() throws Exception {
  System.out.println("Server is starting.");
  //         3 CountDownLatch
  CountDownLatch latch = new CountDownLatch(3);
  // 3        3   
  ExecutorService service = Executors.newCachedThreadPool();
  service.submit(new ComponentThread(latch, 1));
  service.submit(new ComponentThread(latch, 2));
  service.submit(new ComponentThread(latch, 3));
  service.shutdown();
 
  
  //  3            
  latch.await();
 
  
  //            ，Server     
  System.out.println("Server is up!");
 }
 
  
 public static void main(String[] args) throws Exception {
  CountDownLatchTest.startServer();
 }
}