Databases
StackOverflow2013
Postsdbo
POWhy doesn't the EDT shut down when all live threads are daemon?
Body
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POWhy doesn't the EDT shut down when all live threads are daemon?
    text
    copied!<p>The following code slides a <a href="http://upload.wikimedia.org/wikipedia/commons/thumb/d/d5/Queen_of_diamonds_en.svg/209px-Queen_of_diamonds_en.svg.png" rel="nofollow noreferrer">card</a> across the screen. When I shut down the main window, I expect the event dispatch thread to shut down as well, but it does not. Any ideas on why the ScheduledExecutorService thread prevents the EDT from shutting down?</p> <pre><code>import java.awt.Graphics; import java.net.URL; import java.util.concurrent.Executors; import java.util.concurrent.ScheduledExecutorService; import java.util.concurrent.ThreadFactory; import java.util.concurrent.TimeUnit; import javax.swing.ImageIcon; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.SwingUtilities; public class Main extends JPanel { private float x = 1; public void next() { x *= 1.1; System.out.println(x); repaint(); } @Override protected void paintComponent(Graphics g) { super.paintComponent(g); URL url = getClass().getResource("/209px-Queen_of_diamonds_en.svg.png"); g.drawImage(new ImageIcon(url).getImage(), (int) x, 50, null); } public static void main(String[] args) { JFrame frame = new JFrame(); final Main main = new Main(); frame.getContentPane().add(main); frame.setSize(800, 600); frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE); frame.setVisible(true); ScheduledExecutorService timer = Executors.newScheduledThreadPool(1, new ThreadFactory() { public Thread newThread(Runnable r) { Thread result = new Thread(r); result.setDaemon(true); return result; } }); timer.scheduleAtFixedRate(new Runnable() { public void run() { SwingUtilities.invokeLater(new Runnable() { public void run() { main.next(); } }); } }, 100, 100, TimeUnit.MILLISECONDS); } } </code></pre>
 

Querying!

 
Guidance
An individual column

Larger individual text columns get their own page to allow for proper reading.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload