Re: Avoiding NPEs caused by indirect call
Royan wrote:
And the second one (which has made me to start this thread) was when I
derived from the JDialog and overridden addXxxx and fireXxx methods.
Because this case is somewhat easier to reproduce I've written a very
small test case that demonstrates my original problem:
Your original test case was excellent, no worries. I think however now
that we know you base class is JDialog... I'm not sure there's much to
be done. Apparently, JDialog is poorly designed for the type of
inheritance you want to do. So, you can't do that.
I'm not sure what's up with the property change listener. I've never
used one (directly) and I don't know why it's firing in the constructor.
There might be a better way of using the property change listener.
Some things you might consider:
1. Wrap the JDialog instead of extending it.
class SampleDialog {
private JDialog jd;
private PropertyChangeSupport pcs;
//... etc.
}
2. Extend java.awt.dialog instead of JDialog.
3. Look into other ways to use property change listeners.
#3 seems like the first thing you should do. While JDialog might not be
the best class to extend, I don't see why you can't extend
DefaultTableModel (although it may not be designed for inheritance
either. AbstractTableModel seems to be the class to extend.) So you
might be doing something iffy with the property change listeners here.
I'm not really sure because I don't have any experience with them.