Recently I have been creating buttons that have no text. They just display an image that I loaded as the icon of the button. How does the applet know which control generated the event?
It turns out that you can call setActionCommand and pass it a String. This String is when the applet will get when it tries to get the command. It puts you back in control for the event processing.
Here is a tip I discovered the hard way. Make sure you addActionListener(this) on the button you want to handle events for. Otherwise the applet will never get a notification that your button was clicked. This might be obvious. But it is painful to debug when you forget to make the call.