以下是使组件居中的四种方法：
import java.awt.*;import javax.swing.*;import javax.swing.border.*;class CenterComponent { public static JLabel getLabel(String text) { return getLabel(text, SwingConstants.LEFT); } public static JLabel getLabel(String text, int alignment) { JLabel l = new JLabel(text, alignment); l.setBorder(new LineBorder(Color.RED, 2)); return l; } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { public void run() { JPanel p = new JPanel(new GridLayout(2,2,4,4)); p.setBackground(Color.black); p.setBorder(new EmptyBorder(4,4,4,4)); JPanel border = new JPanel(new BorderLayout()); border.add(getLabel( "Border", SwingConstants.CENTER), BorderLayout.CENTER); p.add(border); JPanel gridbag = new JPanel(new GridBagLayout()); gridbag.add(getLabel("GridBag")); p.add(gridbag); JPanel grid = new JPanel(new GridLayout()); grid.add(getLabel("Grid", SwingConstants.CENTER)); p.add(grid); // from @0verbose JPanel box = new JPanel(); box.setLayout(new BoxLayout(box, BoxLayout.X_AXIS )); box.add(Box.createHorizontalGlue()); box.add(getLabel("Box")); box.add(Box.createHorizontalGlue()); p.add(box); Jframe f = new Jframe("Streeeetch me.."); f.setDefaultCloseOperation(Jframe.EXIT_ON_CLOSE); f.setContentPane(p); f.pack(); f.setLocationByPlatform(true); f.setVisible(true); } }); }}
