JRadioButton.setSelected( false ) ?

Question

First of all, I just read the thread "Secret source of answers to your problems...." and want to assure anyone reading this that I have been looking at the Java API all morning and I'm ready to rip this Java textbook into shreds.
I have a homework assignment and while I am not asking anyone to do my homework for me, I have run up against a brick wall. I have two sets of JRadioButtons (using two ButtonGroups). I also have two JButtons - one of which I want to use to clear the form, including clearing the JRadioButton selections.
According to the API - I should be able to set a radio button's "selected" to false. But it isn't working for me.
Here is the snippet of code I am using in my ActionListener event handler for the Clear button. All of it works except for the setSelected method call:
if ( event.getSource() == clearButton )
    tempField.setText( "" );            // clear text field
    inCelButton.setSelected( false );  // clear radio button
    inFahButton.setSelected( false );  // selections
    inKelButton.setSelected( false );  // inButton Group
    inCelButton.setVisible( true );    // set radio buttons
    inFahButton.setVisible( true );    // to visible
    inKelButton.setVisible( true );
    outCelButton.setSelected( false ); // clear radio button
    outFahButton.setSelected( false ); // selections
    outKelButton.setSelected( false ); // outButton Group
    outCelButton.setVisible( true );   // set radio buttons
    outFahButton.setVisible( true );   // to visible
    outKelButton.setVisible( true );
    results="";                        // clear results string
    resultsLabel.setText("");          // clear results label
}TIA
Sheryl McKenna

Answer 1

It's not necessarily true that you have to have a button selected. It only works this way when you use a buttongroup. The buttongroup insists that one button be selected when all others are off. This is the API information (Which it sounds like you are already familiar with)
"Initially, all buttons in the group are unselected. Once any button is selected, one button is always selected in the group. There is no way to turn a button programmatically to "off", in order to clear the button group. To give the appearance of "none selected", add an invisible radio button to the group and then programmatically select that button to turn off all the displayed radio buttons. For example, a normal button with the label "none" could be wired to select the invisible radio button."
I just wrote a simple app to test this and it worked fine for me. The button group ensures you can't select multiple buttons. After you select one, all others are automatically de-selected. If you are really set on using a group of buttons, without the buttonGroup then I would add a panel, set the layout to null and then just add the buttons. Netbeans is a great way to test your UI without writing a lot of code and see the end results quickly. It's free and it's available at:
http://www.netbeans.org.