Retaining selection without having unique IDs for each row is tricky
business. What you can try to do is to save selection before sort and
restore selection after sort.

1) Let table get notifications about row delete/insert
  * i.e. standard JTable selection behaviour
2) Save selection
  * i.e. resolve sorted selection rows into actual model's rows
3) do sorting
4) Restore selection
  * i.e. try to map model rows back to sorted rows
  * If selected rows haven't really changed, then don't touch selection.
5) Notify table that contents has changed

For save/restore you may establish some listener.

If you can use some column values as unique IDs then selection restore can
be more robust.

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KI