How to prompt a confirmation dialog box in the middle of non event dispatching thread

Question

I have the following fun which will be executed by non event dispatching thread. In the middle of thread, I want a

1. A confirmation box pop up. Thread suspend its execution.
2. User makes a choice.
3. Thread will get the choice and continue execution.

However, I find out it is not easy to do it in thread safety way, as dialog box should be shown by event dispatching thread. I try

public int fun()
{
    // The following code will be executed by non event dispatching thread.
    final int choice;
    SwingUtilities.invokeAndWait(new Runnable() {

        @Override
        public void run() {
            // Error.
            choice = JOptionPane.showConfirmDialog(SaveToCloudJDialog.this, message, title, JOptionPane.YES_NO_OPTION);
        }            
    });
    return choice;
}

Of course this won't work as choice is final, and I cannot assign the returned value from dialog to it.

What is the correct way to achieve the above 3 objectives?

Answer 1

Have you tried:

public int fun()
{
    // The following code will be executed by non event dispatching thread.
    final int[] choice = new int[1];
    SwingUtilities.invokeAndWait(new Runnable() {
        @Override
        public void run() {
            // Error.
            choice[0] = JOptionPane.showConfirmDialog(SaveToCloudJDialog.this, message, title, JOptionPane.YES_NO_OPTION);
        }            
    });
    return choice[0];
}