线程之Thread和Runnable

Runnable:

public class threadTest implements  Runnable{

    private AtomicInteger tickets = new AtomicInteger(3);
    public void run() {
        int ticketNum ;
        while((ticketNum = tickets.getAndDecrement())>0)
        {
            System.out.println(Thread.currentThread().getName()+" "+ticketNum);
        }
    }

public class Test {
    public static void main(String[] args)
    {
        threadTest t = new threadTest();
        new Thread(t).start();
        new Thread(t).start();
    }
}
其中一次的结果为：

Thread-0 3
Thread-1 2
Thread-0 1

Thread：

public class threadTest extends Thread{

    private AtomicInteger tickets = new AtomicInteger(3);
    public void run() {
        int ticketNum ;
        while((ticketNum = tickets.getAndDecrement())>0)
        {
            System.out.println(Thread.currentThread().getName()+" "+ticketNum);
        }
    }

public class Test {
    public static void main(String[] args)
    {
        new threadTest().start();
        new threadTest().start();
    }
}
其中一次结果：

Thread-1 3
Thread-0 3
Thread-1 2
Thread-0 2
Thread-1 1
Thread-0 1

在网上有看到说通过Runnable实现的线程能够共享资源，而继承Thread的线程不能共享资源。这个例子是说明这个问题吗？