//4、针对 interrupt 设计的作业。

//要求：

//(1)创建一个线程，让这个线程不断的打印一个字符串(每隔0.5秒打印一个字符串)

//(2)当线程启动 2秒后，调用线程的 interrupt 方法时，让线程不再打印字符串，并退出线程

//(用 isInterrupted() 方法来判断是否调用了 interrupt 方法，来控制线程的退出)-//4, the design for the interrupt job.// Requirements:// (1) create a thread, so that the constant thread prints a string (every 0.5 seconds to print a string)// (2) when the thread starts 2 seconds after the calling thread' s interrupt method , so that the thread is no longer print string and exit the thread// (used isInterrupted () method to determine whether to call the interrupt method to control the thread' s exit)