import java.awt.datatransfer.*;

static void listEnableTextDrag(final JList list) {
  TransferHandler th = new TransferHandler {
    @Override
    public int getSourceActions(JComponent c) { ret COPY; }

    @Override
    protected Transferable createTransferable(JComponent c) {
      O o = selectedListElement(list);
      //print("Value: " + o);
      return new StringSelection(str(o));
    }
  };
  listEnableDrag(list, th);
}

Began life as a copy of #1007218