Colocar imagenes en un JComboBox

import java.awt.Component;
import java.io.File;
import javax.swing.ImageIcon;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.ListCellRenderer;
/**
 * @web https://www.jc-mouse.net/
 * @author Mouse
 */
public class JChomboRenderer  extends JLabel implements ListCellRenderer{

    private ImageIcon[] items;
    /** Constrcutor de clase */
    public JChomboRenderer( ImageIcon[] items )
    {
        setOpaque(true);
        this.items = items;            
    }

    @Override
    public Component getListCellRendererComponent(JList list, Object value, 
                     int index, boolean isSelected, boolean cellHasFocus) {

       int selectedIndex = ((Integer)value).intValue();

       if (isSelected) 
       {
            setBackground(list.getSelectionBackground());
            setForeground(list.getSelectionForeground());
       } else {
            setBackground(list.getBackground());
            setForeground(list.getForeground());
       }

        ImageIcon icon = this.items[selectedIndex];
        setIcon( icon );
        File f = new File( items[selectedIndex].toString() );        
        setText( f.getName() );
        return this;

    }

}

import java.awt.Dimension;
import javax.swing.JComboBox;
/**
 * @web https://www.jc-mouse.net/
 * @author Mouse
 */
public class JChomboBox extends JComboBox {

    /** COnstructor de clase */    
    public JChomboBox( int num_items  )
    {   
        Dimension d = new Dimension(206,26);
        this.setSize(d);
        this.setPreferredSize(d);
        //Indices para las imagenes
        for( int i=0; i<num_items; i++)
        {
            this.addItem(i);
        }    
        this.setVisible(true);
    }

}//--> fin clase

  //instancia
    private JChomboBox jchombobox;     
    //Array de imagenes
    private ImageIcon[] items =
    {            
            new ImageIcon(getClass().getResource("/com/bo/res/clock.png")),
            new ImageIcon(getClass().getResource("/com/bo/res/globe.png")),
            new ImageIcon(getClass().getResource("/com/bo/res/pages.png")),
            new ImageIcon(getClass().getResource("/com/bo/res/recycle.png"))            
    };

    /**
 * Creates new form JFrame1
 */
    public JFrame1() {
        initComponents();

        //=========================
        //se crea el jcombo pasando la cantidad de imagenes que tendra el jcombobox
        jchombobox = new JChomboBox( items.length );
        //se crea y añade un render pasando un array con las imagenes
        JChomboRenderer render = new JChomboRenderer( items );
        jchombobox.setRenderer(render);
        //se añade jcombo al JFrame
        this.add(jchombobox);        
        //Evento Listener
        jchombobox.addActionListener (new ActionListener () {
            @Override
            public void actionPerformed(ActionEvent e) {
                //Acción cuando se selecciona un valor del jcombo
                System.out.println( "Se selecciono imagen " +  jchombobox.getSelectedItem() );
            }
        });
        //=========================
    }