How to show a message when no jradiobutton is selected?

Question

I am doing a java swing exercise that contains the following screen with Jradiobuttons:

When "java swing" is selected it should show a message by clicking on Jbutton and vice versa with the second option. But how to show a message when there is no option selected?

    private void clickEvento(java.awt.event.ActionEvent evt) {                             

    if (jrbJavaSwing.isSelected()) {
        JOptionPane.showMessageDialog(null, "Java Swing");
    }
    if (jrbOutraLP.isSelected()) {
        JOptionPane.showMessageDialog(null, "Outra linguagem... Tem certeza?");
    }
    JOptionPane.showMessageDialog(null, "Você não selecionou nada");

Because that way with this Joptionpane on the last line, it keeps returning the message always.

Answer 1

The method isSelected returns a Boolean, he returns false if not selected, then:

private void clickEvento(java.awt.event.ActionEvent evt) {                             

    if (jrbJavaSwing.isSelected()) {
        JOptionPane.showMessageDialog(null, "Java Swing");
    }
    if (jrbOutraLP.isSelected()) {
        JOptionPane.showMessageDialog(null, "Outra linguagem... Tem certeza?");
    }
    if (jrbJavaSwing.isSelected() == false && jrbOutraLP.isSelected() == false) {
        JOptionPane.showMessageDialog(null, "Você não selecionou nada");
    }
}