Swing question

I want a interface with three vertical panes. The idea is that the user can resize the panes by dragging the two dividers. It would look something like this:

+-----+-----+-----+
|     |     |     |
|     |     |     |
|     |     |     |
|     |     |     |
|     |     |     |
+-----+-----+-----+ 

JSplitPane does this sort of thing, but only for two panes. I can get close to what I want by nesting JSplitPanes. The re-sizing works fine, but it looks wrong because there are too many borders:

+-----+-----------+
|     |+----+----+|
|     ||    |    ||
|     ||    |    ||
|     ||    |    ||
|     |+----+----+|
+-----+-----------+

Any other suggestions?