How come my program doesn't shut down when all windows are closed?

Question

As of Java 1.5 (maybe earlier) java is supposed to exit when all windows have been closed. I have confirmed that this happens in a simple case of displaying 2 JFrames and closing both. Can anyone tell me why it's not happening in the case of 2 frames and 1 dialog here?
* Created on Jul 12, 2006 by @author Tom Jacobs
package tjacobs.ui;
import java.awt.Component;
import java.awt.Dialog;
import java.awt.Frame;
import java.awt.GraphicsConfiguration;
import java.awt.HeadlessException;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ComponentEvent;
import java.awt.event.ComponentListener;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
public class ModalOnParentDialog extends JDialog implements ComponentListener,
          WindowListener {
     private Component mOwner;
     private boolean mParentOnly = false;
     public ModalOnParentDialog() throws HeadlessException {
          super();
          init(null);
     public ModalOnParentDialog(Frame arg0) throws HeadlessException {
          super(arg0);
          init(arg0);
     public ModalOnParentDialog(Frame arg0, boolean arg1)
               throws HeadlessException {
          super(arg0, arg1);
          init(arg0);
     public ModalOnParentDialog(Frame arg0, String arg1)
               throws HeadlessException {
          super(arg0, arg1);
          init(arg0);
     public ModalOnParentDialog(Frame arg0, String arg1, boolean arg2)
               throws HeadlessException {
          super(arg0, arg1, arg2);
          init(arg0);
     public ModalOnParentDialog(Frame arg0, String arg1, boolean arg2,
               GraphicsConfiguration arg3) {
          super(arg0, arg1, arg2, arg3);
          init(arg0);
     public ModalOnParentDialog(Dialog arg0) throws HeadlessException {
          super(arg0);
          init(arg0);
     public ModalOnParentDialog(Dialog arg0, boolean arg1)
               throws HeadlessException {
          super(arg0, arg1);
          init(arg0);
     public ModalOnParentDialog(Dialog arg0, String arg1)
               throws HeadlessException {
          super(arg0, arg1);
          init(arg0);
     public ModalOnParentDialog(Dialog arg0, String arg1, boolean arg2)
               throws HeadlessException {
          super(arg0, arg1, arg2);
          init(arg0);
     public ModalOnParentDialog(Dialog arg0, String arg1, boolean arg2,
               GraphicsConfiguration arg3) throws HeadlessException {
          super(arg0, arg1, arg2, arg3);
          init(arg0);
     private void init(Component c) {
          mOwner = c;
          addComponentListener(this);
          addWindowListener(this);
     public void componentResized(ComponentEvent arg0) {}
     public void componentMoved(ComponentEvent arg0) {}
     public void componentShown(ComponentEvent arg0) {
          doModalOp();
     public void componentHidden(ComponentEvent arg0) {
          doModalOp();
     public boolean isParentOnly() {
          return mParentOnly;
     public void setParentOnly(boolean b) {
          mParentOnly = b;
     public void setModal(boolean b) {
          super.setModal(b);
          //mModal = b;
          doModalOp();
     private void doModalOp() {
          if (mOwner != null) {
               mOwner.setEnabled(!super.isModal() || !isVisible());
     public boolean isModal() {
          return super.isModal() && !mParentOnly;
//     public boolean isParentModel() {
//          return mModal;
     public void windowOpened(WindowEvent arg0) {
          doModalOp();
     public void windowClosing(WindowEvent arg0) {}
     public void windowClosed(WindowEvent arg0) {
          doModalOp();
     public void windowIconified(WindowEvent arg0) {}
     public void windowDeiconified(WindowEvent arg0) {}
     public void windowActivated(WindowEvent arg0) {}
     public void windowDeactivated(WindowEvent arg0) {}
     protected void finalize() throws Throwable {
          super.finalize();
          removeComponentListener(this);
          removeWindowListener(this);
          mOwner = null;
     public static void main(String[] args) {
          JFrame jf1 = new JFrame("1"), jf2 = new JFrame("2");
          final ModalOnParentDialog d = new ModalOnParentDialog(jf1, "3");
          d.setModal(true);
          d.setParentOnly(true);
          JButton b = new JButton("Show");
          b.addActionListener(new ActionListener() {
               public void actionPerformed(ActionEvent ae) {
                    d.setVisible(!d.isVisible());
          jf1.setBounds(0,0,40,40);
          jf2.setBounds(40,40,40,40);
          jf2.add(b);
          d.setBounds(80,80,40,40);
          jf1.setVisible(true);
          jf2.setVisible(true);
          d.setVisible(true);
}

Answer 1

I fixed it
* Created on Jul 12, 2006 by @author Tom Jacobs
package tjacobs.ui;
import java.awt.Component;
import java.awt.Dialog;
import java.awt.Frame;
import java.awt.GraphicsConfiguration;
import java.awt.HeadlessException;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ComponentEvent;
import java.awt.event.ComponentListener;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
public class ModalOnParentDialog extends JDialog implements ComponentListener,
          WindowListener {
     private Component mOwner;
     private boolean mParentOnly = false;
     public ModalOnParentDialog() throws HeadlessException {
          super();
          init(null);
     public ModalOnParentDialog(Frame arg0) throws HeadlessException {
          super(arg0);
          init(arg0);
     public ModalOnParentDialog(Frame arg0, boolean arg1)
               throws HeadlessException {
          super(arg0, arg1);
          init(arg0);
     public ModalOnParentDialog(Frame arg0, String arg1)
               throws HeadlessException {
          super(arg0, arg1);
          init(arg0);
     public ModalOnParentDialog(Frame arg0, String arg1, boolean arg2)
               throws HeadlessException {
          super(arg0, arg1, arg2);
          init(arg0);
     public ModalOnParentDialog(Frame arg0, String arg1, boolean arg2,
               GraphicsConfiguration arg3) {
          super(arg0, arg1, arg2, arg3);
          init(arg0);
     public ModalOnParentDialog(Dialog arg0) throws HeadlessException {
          super(arg0);
          init(arg0);
     public ModalOnParentDialog(Dialog arg0, boolean arg1)
               throws HeadlessException {
          super(arg0, arg1);
          init(arg0);
     public ModalOnParentDialog(Dialog arg0, String arg1)
               throws HeadlessException {
          super(arg0, arg1);
          init(arg0);
     public ModalOnParentDialog(Dialog arg0, String arg1, boolean arg2)
               throws HeadlessException {
          super(arg0, arg1, arg2);
          init(arg0);
     public ModalOnParentDialog(Dialog arg0, String arg1, boolean arg2,
               GraphicsConfiguration arg3) throws HeadlessException {
          super(arg0, arg1, arg2, arg3);
          init(arg0);
     private void init(Component c) {
          mOwner = c;
          addComponentListener(this);
          addWindowListener(this);
     public void componentResized(ComponentEvent arg0) {}
     public void componentMoved(ComponentEvent arg0) {}
     public void componentShown(ComponentEvent arg0) {
          doModalOp();
     public void componentHidden(ComponentEvent arg0) {
          doModalOp();
     public boolean isParentOnly() {
          return mParentOnly;
     public void setParentOnly(boolean b) {
          mParentOnly = b;
     public void setModal(boolean b) {
          super.setModal(b);
          //mModal = b;
          doModalOp();
     private void doModalOp() {
          if (mOwner != null) {
               mOwner.setEnabled(!super.isModal() || !isVisible());
     public boolean isModal() {
          return super.isModal() && !mParentOnly;
//     public boolean isParentModel() {
//          return mModal;
     public void windowOpened(WindowEvent arg0) {
          doModalOp();
     public void dispose() {
          //setVisible(false);
          //doModalOp();
          if (mOwner != null) {
               mOwner.setEnabled(true);
          removeComponentListener(this);
          removeWindowListener(this);
          super.dispose();
     public void pack() {
          super.pack();
          addListeners();
     private boolean addListeners() {
          WindowListener[] listeners = this.getWindowListeners();
          if (listeners != null) {
               for (int i = 0; i < listeners.length; i++) {
                    if (listeners[i] == this) return false;
          addComponentListener(this);
          addWindowListener(this);
          return true;
     public void show() {
          super.show();
          addListeners();
     public void show(boolean b) {
          super.show(b);
          addListeners();
     public void windowClosing(WindowEvent arg0) {}
     public void windowClosed(WindowEvent arg0) {
          doModalOp();
     public void windowIconified(WindowEvent arg0) {}
     public void windowDeiconified(WindowEvent arg0) {}
     public void windowActivated(WindowEvent arg0) {}
     public void windowDeactivated(WindowEvent arg0) {}
     public static void main(String[] args) {
          JFrame jf1 = new JFrame("1"), jf2 = new JFrame("2");
          final ModalOnParentDialog d = new ModalOnParentDialog(jf1, "3");
          d.setModal(true);
          d.setParentOnly(true);
          JButton b = new JButton("Show");
          b.addActionListener(new ActionListener() {
               public void actionPerformed(ActionEvent ae) {
                    d.setVisible(!d.isVisible());
          jf1.setBounds(0,0,40,40);
          jf1.setDefaultCloseOperation(jf1.DISPOSE_ON_CLOSE);
          jf2.setDefaultCloseOperation(jf2.DISPOSE_ON_CLOSE);
          d.setDefaultCloseOperation(d.DISPOSE_ON_CLOSE);
          jf2.setBounds(40,40,40,40);
          jf2.add(b);
          d.setBounds(80,80,40,40);
          jf1.setVisible(true);
          jf2.setVisible(true);
          d.setVisible(true);
}