How can I create a JOptionPane that will return two input values?

This might not exactly "return" two values but may be used to get two values from the user

JPanel p = new JPanel(new GridLayout(0,1));
JTextField tf1 = new JTextField();
p.add(tf1);

JTextField tf2 = new JTextField();
p.add(tf2);

if (JOptionPane.showConfirmDialog(null // may want to pass your application frame here
                           ,p
                           ,"Input two values"
                           ,JOptionPane.OK_CANCEL_OPTION
                           ,JOptionPane.PLAIN_MESSAGE 
                            ) == JOptionPane.OK_OPTION) {
  // use the tf1.getText()
  // use the tf2.getText()
}