Swing/BoxLayoutAlignment のバックアップ(No.1)

JLabel l2 = new JLabel("abc") {
  @Override public Dimension getPreferredSize() {
    return new Dimension(50, 50);
  }
  @Override public Dimension getMinimumSize() {
    Dimension d = super.getMinimumSize();
    if (d != null) {
      d.width = value;
      d.height = value;
    }
    return d;
  }
};
l2.setOpaque(true);
l2.setBackground(Color.ORANGE);
l2.setFont(l.getFont().deriveFont(Font.PLAIN));
l2.setAlignmentX(Component.CENTER_ALIGNMENT);
l2.setAlignmentY(Component.CENTER_ALIGNMENT);
l2.setVerticalAlignment(SwingConstants.CENTER);
l2.setVerticalTextPosition(SwingConstants.CENTER);
l2.setHorizontalAlignment(SwingConstants.CENTER);
l2.setHorizontalTextPosition(SwingConstants.CENTER);

final JPanel p2 = new TestPanel();
p2.setLayout(new BoxLayout(p2, BoxLayout.Y_AXIS));
p2.add(Box.createVerticalGlue());
p2.add(l2);
p2.add(Box.createVerticalGlue());