Java Swing - 如何改变看和感觉

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.border.TitledBorder;
import javax.swing.table.DefaultTableModel;

public class Main {

  public static void main(String[] args) {
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JPanel gui = new JPanel(new BorderLayout(5, 5));

    JPanel plafComponents = new JPanel(new FlowLayout(FlowLayout.RIGHT, 3, 3));
    plafComponents.setBorder(new TitledBorder(
        "FlowLayout(FlowLayout.RIGHT, 3,3)"));

    UIManager.LookAndFeelInfo[] plafInfos = UIManager
        .getInstalledLookAndFeels();
    String[] plafNames = new String[plafInfos.length];
    for (int ii = 0; ii < plafInfos.length; ii++) {
      plafNames[ii] = plafInfos[ii].getName();
    }
    JComboBox plafChooser = new JComboBox(plafNames);
    plafComponents.add(plafChooser);

    JCheckBox pack = new JCheckBox("Pack on PLAF change", true);
    plafComponents.add(pack);

    plafChooser.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent ae) {
        int index = plafChooser.getSelectedIndex();
        try {
          UIManager.setLookAndFeel(plafInfos[index].getClassName());
          SwingUtilities.updateComponentTreeUI(frame);
          if (pack.isSelected()) {
            frame.pack();
            frame.setMinimumSize(frame.getSize());
          }
        } catch (Exception e) {
          e.printStackTrace();
        }
      }
    });

    gui.add(plafComponents, BorderLayout.NORTH);

    JPanel dynamicLabels = new JPanel(new BorderLayout(4, 4));
    dynamicLabels.setBorder(new TitledBorder("BorderLayout(4,4)"));
    gui.add(dynamicLabels, BorderLayout.WEST);

    final JPanel labels = new JPanel(new GridLayout(0, 2, 3, 3));
    labels.setBorder(new TitledBorder("GridLayout(0,2,3,3)"));

    JButton addNew = new JButton("Add Another Label");
    dynamicLabels.add(addNew, BorderLayout.NORTH);
    addNew.addActionListener(new ActionListener() {

      private int labelCount = 0;

      public void actionPerformed(ActionEvent ae) {
        labels.add(new JLabel("Label " + ++labelCount));
        frame.validate();
      }
    });

    dynamicLabels.add(new JScrollPane(labels), BorderLayout.CENTER);

    String[] header = { "Name", "Value" };
    String[] a = new String[0];
    String[] names = System.getProperties().stringPropertyNames().toArray(a);
    String[][] data = new String[names.length][2];
    for (int ii = 0; ii < names.length; ii++) {
      data[ii][0] = names[ii];
      data[ii][1] = System.getProperty(names[ii]);
    }
    DefaultTableModel model = new DefaultTableModel(data, header);
    JTable table = new JTable(model);
        
    JScrollPane tableScroll = new JScrollPane(table);
    Dimension tablePreferred = tableScroll.getPreferredSize();
    tableScroll.setPreferredSize(new Dimension(tablePreferred.width,
        tablePreferred.height / 3));

    JPanel imagePanel = new JPanel(new GridBagLayout());
    JLabel imageLabel = new JLabel("test");
    imagePanel.add(imageLabel, null);

    JSplitPane splitPane = new JSplitPane(JSplitPane.VERTICAL_SPLIT,
        tableScroll, new JScrollPane(imagePanel));
    gui.add(splitPane, BorderLayout.CENTER);

    frame.setContentPane(gui);
    frame.pack();
    frame.setVisible(true);
  }

}