android 利用countDownLatch实现主线程与子线程之间的同步

   // author:liu_zl
 1 public class CountDownLatchActivity extends Activity implements OnClickListener{
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.latch_activity);
        //定义countDownLatch, 计数为2：表示有两个线程
        CountDownLatch countDownLatch = new CountDownLatch(2);
        MyThread myThread1 = new MyThread(countDownLatch,"myThread1");
        MyThread myThread2 = new MyThread(countDownLatch, "myThread2");
        // 开启两个子线程
        myThread1.start();
        myThread2.start();
        try {
            //主线程等待
            countDownLatch.await();
            endWork();
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        
    }
    public void onClick(View v) {
    }
    
    /*
     * 子线程执行完毕，主线程执行的方法
     */
    private void endWork() {
        System.out.println("end work");
    }
    
    class MyThread extends Thread {
        private CountDownLatch countDownLatch;
        private String nameString;
        public MyThread(CountDownLatch countDownLatch, String name) {
            this.countDownLatch = countDownLatch;
            this.nameString = name;
        }
        @Override
        public void run() {
            // TODO Auto-generated method stub
            doWorking();
            countDownLatch.countDown(); //计数减一，直到计数为零
            complete();
            super.run();
        }
        /**
         * 子线程开始执行
         */
        private void doWorking() {
            System.out.println(nameString+"\t do working");
        }
        
        /**
         * 子线程执行结束
         */
        private void complete() {
            System.out.println(nameString+"\t completed");
        }
    }
    
    
}