13.7 Avoiding Errors and Debugging

Avoiding Errors

1. If you change the contents of a window, be sure to redraw it. To do so, call the repaint method, not the paint method. If you call repaint, the window manager will automatically call paint at an appropriate time.
2. In implementing an interface, be sure to include all required methods with exactly the right parameters. If anything is missing or wrong, the compiler will complain.

Debugging

1. If a component is not responding as it should, check that you have registered the component as a listener to the appropriate action. For example, if a button is not responding to mouse clicks, check to see if you have implemented the ActionListener interface for that button object. If the component is not registered as a listener, then its actionPerformed method will not be executed.