look and feel.txt

1]
            // Set cross-platform Java L&F (also called "Metal")
        UIManager.setLookAndFeel(UIManager.getCrossPlatformLookAndFeelClassName());
 2]
            // Set System L&F
        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
3]
UIManager.setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel");

4]
UIManager.setLookAndFeel("com.sun.swing.plaf.motif.MotifLookAndFeel");

5]
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) 
{
	System.out.println(info.getName());
	/*if ("Nimbus".equals(info.getName())) 
	{
		javax.swing.UIManager.setLookAndFeel(info.getClassName());
        break;
	}*/
}

Name and ClassNames
Metal : javax.swing.plaf.metal.MetalLookAndFeel
Nimbus : javax.swing.plaf.nimbus.NimbusLookAndFeel
CDE/Motif : com.sun.java.swing.plaf.motif.MotifLookAndFeel
Windows : com.sun.java.swing.plaf.windows.WindowsLookAndFeel
Windows Classic : com.sun.java.swing.plaf.windows.WindowsClassicLookAndFeel