StringUtils.isNumeric blocks JOptionPane cancel option

Question

This is the code I'm using to process the input of an integer :

public static int getIntInput(String message) {
    String numberStr = JOptionPane.showInputDialog(message);
    while (!StringUtils.isNumeric(numberStr) || Integer.parseInt(numberStr) == 0) {
        numberStr = JOptionPane.showInputDialog(message);
    }
    return Integer.parseInt(numberStr);
}

It works fine, except when I want to press "cancel" or close button on the JOption window. When I do that, the JOptionPane window shows up again.

How can I correctly close a JOptionPane window when the cancel or close button is pushed?

Answer 1

while (!StringUtils.isNumeric(numberStr) || Integer.parseInt(numberStr) == 0) {

        if (numberStr == null) {
           return 0; 
        }
        else {
            numberStr = JOptionPane.showInputDialog(message);
        }
}

This does the trick.