How can I create an alt background color for items in a jlistbox or jtree

Question

What I'm looking to do is have a white background for say items 1,3,5, etc. and a light yellow background for items 2,4,6, etc. I was wondering how can I set an alternative background color on items in a JTree or a JList

Answer 1

Use a cell renderer:
import java.awt.*;
import javax.swing.*;
public class ListAlternating extends JFrame
     public ListAlternating()
          String[] items = {"one", "two", "three", "four", "five", "six", "seven"};
          JList list = new JList( items );
          list.setVisibleRowCount(5);
          list.setCellRenderer( new MyCellRenderer() );
          JScrollPane scrollPane = new JScrollPane( list );
          getContentPane().add( scrollPane );
     public static void main(String[] args)
          ListAlternating frame = new ListAlternating();
          frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
          frame.pack();
          frame.setLocationRelativeTo( null );
          frame.setVisible( true );
     class MyCellRenderer extends DefaultListCellRenderer
          public Component getListCellRendererComponent(
               JList list, Object value, int index, boolean isSelected, boolean cellHasFocus)
               super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
               if (!isSelected)
                    setBackground(index % 2 == 0 ? list.getBackground() : Color.LIGHT_GRAY);
               return this;
}