import java.util.concurrent.*;

public class TestExecutor {
    public static void main(String[] args) {
        Thread daemon = new Thread(new MyDaemon());
        daemon.setDaemon(true);
        daemon.start();
        // ExecutorService executor = Executors.newCachedThreadPool();
        // ExecutorService executor = Executors.newSingleThreadExecutor();
        ExecutorService executor = Executors.newFixedThreadPool(2);
        for (int i = 0; i < 5; i++) {
            executor.execute(new MyRunnable(i));
        }
        executor.shutdown();
    }
}

class MyDaemon implements Runnable {
    @Override
    public void run() {
        while (true) {
            Thread.yield();
            try {
                Thread.sleep(1000);
            } catch (Exception e) {
                e.printStackTrace();
            }
            System.out.println("Daemon is running.");
        }
    }
}