Java实现等待所有子线程结束后再执行一段代码的方法

import java.util.concurrent.CountDownLatch;public class Counter {  public static int count = 0;  static CountDownLatch cdl=new CountDownLatch(1000);//这里的数字，开启几个线程就写几  public synchronized static void inc() throws InterruptedException{//注意，如果不加上synchronized，由于并发写入，结果会小于1000    Thread.sleep(1);    count++;    cdl.countDown();  }  public static void main(String[] args) throws InterruptedException{    for(int i = 0; i < 1000; i++){      new Thread(new Runnable(){        public void run() {          // TODO Auto-generated method stub          try {            Counter.inc();          } catch (InterruptedException e) {            // TODO Auto-generated catch block            e.printStackTrace();          }        }      }      ).start();    }    cdl.await();//主线程等待子线程执行输出    System.out.println(count);  }}