JRadioButton r1=new JRadioButton("A) Male");
JRadioButton r2=new JRadioButton("B) Female");
r1.setBounds(75,50,100,30);
r2.setBounds(75,100,100,30);
ButtonGroup bg=new ButtonGroup();
bg.add(r1);
bg.add(r2);
if(r1.isSelected()){
JOptionPane.showMessageDialog(this,"You are Male.");
}