Java'中的几种Look and Feel
1、Metal风格 (默认)
String lookAndFeel = "javax.swing.plaf.metal.MetalLookAndFeel";
UIManager.setLookAndFeel(lookAndFeel);
2、Windows风格
String lookAndFeel = "com.sun.java.swing.plaf.windows.WindowsLookAndFeel";
UIManager.setLookAndFeel(lookAndFeel);
3、Windows Classic风格
String lookAndFeel = "com.sun.java.swing.plaf.windows.WindowsClassicLookAndFeel";
UIManager.setLookAndFeel(lookAndFeel);
4、Motif风格
String lookAndFeel = "com.sun.java.swing.plaf.motif.MotifLookAndFeel";
UIManager.setLookAndFeel(lookAndFeel);
5、Mac风格 (需要在相关的操作系统上方可实现)
String lookAndFeel = "com.sun.java.swing.plaf.mac.MacLookAndFeel";
UIManager.setLookAndFeel(lookAndFeel);
6、GTK风格 (需要在相关的操作系统上方可实现)
String lookAndFeel = "com.sun.java.swing.plaf.gtk.GTKLookAndFeel";
UIManager.setLookAndFeel(lookAndFeel);
7、可跨平台的默认风格
String lookAndFeel = UIManager.getCrossPlatformLookAndFeelClassName();
UIManager.setLookAndFeel(lookAndFeel);
8、当前系统的风格
String lookAndFeel = UIManager.getSystemLookAndFeelClassName();
UIManager.setLookAndFeel(lookAndFeel);

在Java中让用户能够动态地更改应用的外观，可以给用户更好地体验，具体的实现方式是：
1，先使用UIManager.setLookAndFeel(String s)方法设定对应的外观
2，再使用SwingUtilities.updateComponentTreeUI(Component c)方法立刻更新应用的外观
这两个类均在javax.swing包中