线程调度

public class Test
{
    public static void main(String[] args)
    {
        Thread t1 = new SubThread();
        t1.start();

        for (int i = 0; i < 20; i++)
        {
            System.out.println("主线程第" + i + "次执行！");
            if (i > 2)
                try
                {
                    // t1线程合并到主线程中，主线程停止执行过程，转而执行t1线程，直到t1执行完毕后继续。
                    t1.join();
                }
                catch (InterruptedException e)
                {
                    e.printStackTrace();
                }
        }
    }
}

class SubThread extends Thread
{
    public void run()
    {
        System.out.println("---------------------------------------");
        for (int i = 0; i < 5; i++)
        {
            System.out.println("子线程1第" + i + "次执行！");
        }
        System.out.println("---------------------------------------");
    }
}