守护线程的一段程序在Java7下失效问题

import java.util.concurrent.TimeUnit;
class ADaemon implements Runnable {
    @Override
    public void run() {
        try{
            System.out.println("starting daemon");
            TimeUnit.SECONDS.sleep(1);

        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
             System.out.println("This should always run");
        }
    }
}
public class DaemonsDontRunFinally {
    public static void main(String[] args) {
        Thread t = new Thread(new ADaemon());
        t.setDaemon(true);
        t.start();
        //System.out.println(":");
    }
}

在java6,8下面都能输出starting daemon,但是java7却是什么都不输出,当我在main里加入输出部分才输出starting daemon.
不太了解这部分知识,求指教，谢谢