Remove “X” button in Swing JDialog

Question

Is there a way to remove the close button (\"X\") from the JDialog title bar?

Answer 1

Here is my experience:

• Tried using setUndecorated(true): Made the whole Dialog invisible.
• Tried setDefaultCloseOperation(WindowConstants.DO_NOTHING_ON_CLOSE): This didn't change the behavior at all. My dialog box still closed. Setting the default close operation to DO_NOTHING_ON_CLOSE delegates the close operation to the windowClosing() method of a registered WindowListener.

What worked for me was:

setDefaultCloseOperation(WindowConstants.DO_NOTHING_ON_CLOSE);
//Remove any existing WindowListeners
for (WindowListener wl : this.getWindowListeners()) {
    this.removeWindowListener(wl);
}
this.addWindowListener(new WindowAdapter() {
    @Override
    public void windowClosing(WindowEvent e) {
        if ("Optional condition") {
            JOptionPane.showMessageDialog(null, "You cannot close this window");
        }
    }
});