早上无事看到这个：

public static void main(String[] args)throws InterruptedException{
Thread t = new Thread(new MyThread2());
    t.start();
    System.out.print("main1");
    t.join();
    System.out.print("main2");
}

@Override
public void run() {
    System.out.print("run1");
    System.out.print("run2");
}

}

• 因为join()，main2肯定最后打印；

• run1 run2 打印顺序固定为：run1,run2；

• 主要有点疑惑，main1,和run里面的到底谁先打印？

  run() method of
      * the receiver will be called by the receiver Thread itself (and not the
      * Thread calling start()).
      *
      * @throws IllegalThreadStateException - if this thread has already started.
      * @see Thread#run
      */
     public synchronized void start() {
         checkNotStarted();
     hasBeenStarted = true;
  
     nativeCreate(this,stackSize,daemon);
  }

看到start里的native开头，我就GG了。但是我知道，Thread的start不会阻塞主线程的运行，所以main1打印最先。

然后，敲代码多次运行验证：

G:\java>javac MyThread2.java
G:\java>java MyThread2

main1run1run2main2