关于多线程的问题？

[tomguan]

public class WaitNotify extends Thread {

public static void main(String[] args) {
Thread notificationThread = new WaitNotify();
notificationThread.start();
try {

synchronized (notificationThread) {
System.out.println("before run wait method!");
//notificationThread.wait();
System.out.println("after run wait method!");
}
} catch (Exception e) {

}
System.out.println("the wait is over");
}
public void run() {
System.out.println("Hit enter to stop waiting thread!");

try {
System.in.read();
} catch (Exception e) {

}
synchronized (this) {
this.notifyAll();
}

}

}

请问在上面的程序运行时，总共有几个线程啊，都是那些个？
这个程序到底是怎么运行的啊（线程方面），我现在都晕了，拜托各位大哥了！