简单多线程：龟兔赛跑

@Test
public void test() {
    TR tr = new TR("兔子");
    TR tr1 = new TR("乌龟");
    tr.start();
    tr1.start();
}
class TR extends Thread {
    public TR(String name) {
        super(name);
    }
    @Override
    public void run() {
        for (int i = 1; i < 101; i++) {
            System.out.println(getName() + "说，我跑了" + i + "米");
        }
    }
}