多线程知识

public class Main {

     public static void main(String[] args) throws InterruptedException {

         Thread t1 = new Thread(new T1());
         Thread t2 = new Thread(new T2());
         Thread t3 = new Thread(new T3());

        t1.start();
        t1.join();

        t2.start();
        t2.join();

        t3.start();
        t3.join();

         System.out.println("T1、T2、T3依次工作结束.");
    }

}
加入join方法之后T1，T2，T3不再是无序的线程，按照T1，T2，T3顺序执行了。