Question

I have two radio buttons in frame1. On click on enable radio button, it will popup another frame called frame2. I want, not to close the frame1 while the frame2 is opened. But it get closed when click on the X. I used “frame1.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);”. Still it get closed.

enable.addItemListener(new ItemListener() 
{
  @Override
  public void itemStateChanged(ItemEvent e) 
   {
     // TODO Auto-generated method stub                     
    frame2.setVisible(true);
    frame1.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
    }

Answer 1

Have a look here:
How can a Swing WindowListener veto JFrame closing

What you will need to do is, in frame1 and frame2 you will need to set setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE). Then in the below code:

frame1.addWindowListener(new WindowAdapter() {
@Override
public void windowClosing(WindowEvent e) {
       //check is frame 2 is open.. if it is then return without doing anything, else
       // frame1.dispose();
    }
});