JTableの幅が一定以下で水平スクロールバー、以上で列幅を自動拡張するよう設定

JTable table3 = new JTable(1, 3) {
  @Override public boolean getScrollableTracksViewportWidth() {
    // default: return !(autoResizeMode == AUTO_RESIZE_OFF);
    // no longer work correctly???
    // return getPreferredSize().width < getParent().getWidth();
    Container parent = SwingUtilities.getUnwrappedParent(this);
    if (getPreferredSize().width < parent.getWidth()) {
      setAutoResizeMode(JTable.AUTO_RESIZE_SUBSEQUENT_COLUMNS);
    } else {
      setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
    }
    return super.getScrollableTracksViewportWidth();
  }
};