Remove Top-Level Container on Runtime

Question

Unfortunately, it looks like this recently closed question was not well understood. Here is the typical output:

run:
    Trying to Remove JDialog
    Remove          


        

Answer 1

with the intent to blow away all doubts about EDT and confirm trashgod Updated suggestion, then output to the console is

run:
7163 KB used before GC
    Trying to Remove JDialog
    Remove Cycle Done :-)
405 KB used after GC
    Checking if still exists any of TopLayoutContainers
JFrame
JDialog
    Will Try Remove Dialog again, CycleNo. 1
 -----------------------------------------------------------
3274 KB used before GC
    Trying to Remove JDialog
    Remove Cycle Done :-)
403 KB used after GC
    Checking if still exists any of TopLayoutContainers
JFrame
JDialog
    Will Try Remove Dialog again, CycleNo. 2
 -----------------------------------------------------------
3271 KB used before GC
    Trying to Remove JDialog
    Remove Cycle Done :-)
406 KB used after GC
    Checking if still exists any of TopLayoutContainers
JFrame
JDialog
    Will Try Remove Dialog again, CycleNo. 3
 -----------------------------------------------------------
3275 KB used before GC
    Trying to Remove JDialog
    Remove Cycle Done :-)
403 KB used after GC
    Checking if still exists any of TopLayoutContainers
JFrame
JDialog
 -----------------------------------------------------------
*** End of Cycle Without Success, Exit App ***
BUILD SUCCESSFUL (total time: 26 seconds) 

from code

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.WindowEvent;
import javax.swing.*;

public class RemoveDialogOnRuntime extends JFrame {

    private static final long serialVersionUID = 1L;
    private int contID = 1;
    private boolean runProcess;
    private int top = 20;
    private int left = 20;
    private int maxLoop = 0;
    private javax.swing.Timer timer = null;

    public RemoveDialogOnRuntime() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setPreferredSize(new Dimension(300, 300));
        setTitle("Remove Dialog On Runtime");
        setLocation(150, 150);
        pack();
        setVisible(true);
        Point loc = this.getLocation();
        top += loc.x;
        left += loc.y;
        AddNewDialog();
    }

    private void AddNewDialog() {
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                DialogRemove firstDialog = new DialogRemove();
                startAA();
            }
        });
    }

    private void startAA() {
        timer = new javax.swing.Timer(5000, updateAA());
        timer.setRepeats(false);
        timer.start();
    }

    public Action updateAA() {
        return new AbstractAction("text load action") {

            private static final long serialVersionUID = 1L;

            @Override
            public void actionPerformed(ActionEvent e) {
                timer.stop();
                if (SwingUtilities.isEventDispatchThread()) {
                    Runnable doRun = new Runnable() {

                        @Override
                        public void run() {
                            remWins();
                        }
                    };
                    SwingUtilities.invokeLater(doRun);
                } else {
                    Runnable doRun = new Runnable() {

                        @Override
                        public void run() {
                            remWins();
                        }
                    };
                    SwingUtilities.invokeLater(doRun);
                }
            }
        };
    }

    private void remWins() {
        Runtime runtime = Runtime.getRuntime();
        long total = runtime.totalMemory();
        long free = runtime.freeMemory();
        long max = runtime.maxMemory();
        long used = total - free;
        System.out.println(Math.round(used / 1e3) + " KB used before GC");
        Window[] wins = Window.getWindows();
        for (int i = 0; i < wins.length; i++) {
            if (wins[i] instanceof JDialog) {
                System.out.println("    Trying to Remove JDialog");
                wins[i].setVisible(false);
                wins[i].dispose();
                WindowEvent windowClosing = new WindowEvent(wins[i], WindowEvent.WINDOW_CLOSING);
                wins[i].dispatchEvent(windowClosing);
                Toolkit.getDefaultToolkit().getSystemEventQueue().postEvent(windowClosing);
                runtime = Runtime.getRuntime();
                runtime.gc();
                runtime.runFinalization();
            }
        }
        wins = null;
        System.out.println("    Remove Cycle Done :-)");
        runtime.runFinalization();
        runtime.gc();
        runtime = Runtime.getRuntime();
        total = runtime.totalMemory();
        free = runtime.freeMemory();
        max = runtime.maxMemory();
        used = total - free;
        System.out.println(Math.round(used / 1e3) + " KB used after GC");
        startOO();
    }

    private void startOO() {
        timer = new javax.swing.Timer(5000, updateOO());
        timer.setRepeats(false);
        timer.start();
    }

    public Action updateOO() {
        return new AbstractAction("text load action") {

            private static final long serialVersionUID = 1L;

            @Override
            public void actionPerformed(ActionEvent e) {
                timer.stop();
                timer.stop();
                if (SwingUtilities.isEventDispatchThread()) {
                    Runnable doRun = new Runnable() {//really contraproductive just dealayed

                        @Override
                        public void run() {
                            pastRemWins();
                        }
                    };
                    SwingUtilities.invokeLater(doRun);
                } else {
                    Runnable doRun = new Runnable() {

                        @Override
                        public void run() {
                            pastRemWins();
                        }
                    };
                    SwingUtilities.invokeLater(doRun);
                }
            }
        };
    }

    private void pastRemWins() {
        System.out.println("    Checking if still exists any of TopLayoutContainers");
        Window[] wins = Window.getWindows();
        for (int i = 0; i < wins.length; i++) {
            if (wins[i] instanceof JFrame) {
                System.out.println("JFrame");
                wins[i].setVisible(true);
            } else if (wins[i] instanceof JDialog) {
                System.out.println("JDialog");
                wins[i].setVisible(true);
            }
        }
        if (wins.length > 1) {
            wins = null;
            maxLoop++;
            if (maxLoop <= 3) {
                System.out.println("    Will Try Remove Dialog again, CycleNo. " + maxLoop);
                System.out.println(" -----------------------------------------------------------");
                remWins();
            } else {
                System.out.println(" -----------------------------------------------------------");
                System.out.println("*** End of Cycle Without Success, Exit App ***");
                closeMe();
            }
        }
        startAA();
    }

    private void closeMe() {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                System.exit(0);
            }
        });
    }

    private class DialogRemove extends JDialog {

        private static final long serialVersionUID = 1L;

        DialogRemove(final Frame parent) {
            super(parent, "SecondDialog " + (contID++));
            setLocation(top, left);
            top += 20;
            left += 20;
            setPreferredSize(new Dimension(200, 200));
            setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
            setModalityType(Dialog.ModalityType.MODELESS);
            pack();
            setVisible(true);
        }

        private DialogRemove() {
            setTitle("SecondDialog " + (contID++));
            setLocation(top, left);
            top += 20;
            left += 20;
            setPreferredSize(new Dimension(200, 200));
            setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
            setModalityType(Dialog.ModalityType.MODELESS);
            pack();
            setVisible(true);
        }
    }

    public static void main(String args[]) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                RemoveDialogOnRuntime superConstructor = new RemoveDialogOnRuntime();
            }
        });
    }
}