多线程通信的三大法器，你真的会用吗？

/**
 * 微信公众号：Java技术栈
 */
public static void main(String[] args) {
  Object lock = new Object();
  Thread t1 = new Thread(() -> {
    synchronized (lock) {
      for (int i = 0; i < 20; i++) {
        System.out.print(i);
        if (i == 10) {
          try {
            lock.wait();
          } catch (InterruptedException e) {
            e.printStackTrace();
          }
        }
      }
    }
  });
  Thread t2 = new Thread(() -> {
    synchronized (lock) {
      try {
        Thread.sleep(5000);
      } catch (InterruptedException e) {
        e.printStackTrace();
      }
      System.out.print("Java技术栈");
      lock.notifyAll();
    }
  });
  t1.start();
  t2.start();
}