Inventory program part 5 help

Question

This is what I need,
Modify the Inventory Program by adding a button to the GUI that allows the user to move to the first item, the previous item, the next item, and the last item in the inventory. If the first item is displayed and the user clicks on the Previous button, the last item should display. If the last item is displayed and the user clicks on the Next button, the first item should display.
Add a company logo to the GUI using Java graphics classes.
This is what I have so far,
import java.awt.*;
import java.awt.event.*;
import java.text.NumberFormat; // used to format currency
import javax.swing.*;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
class InventoryMain implements ActionListener
    CD[] product;
    JTextField[] fields;
    NumberFormat nf;
    public void actionPerformed(ActionEvent e)
        int index = ((JComboBox)e.getSource()).getSelectedIndex();
        populateFields(index);
    public static void main(String[] args)
        try
            UIManager.setLookAndFeel(
                    "com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
        catch (Exception e)
            System.err.println(e.getClass().getName() + ": " + e.getMessage());
        InventoryMain test = new InventoryMain();
        test.initCD();
        test.showGUI();
        test.populateFields(0);
    public void initCD() {
        //Create an array   
        product = new CD[10];
        //fill in the classes
        product[0] = new CD( 1, "Crowbar" , 20.00, 10, "00722");
        product[1] = new CD( 2, "Pantera" , 20.00, 10, "00263");
        product[2] = new CD( 3, "Ozzy" , 15.00, 10, "00142");
        product[3] = new CD( 4, "Soulfly" , 18.00, 10, "00553");
        product[4] = new CD( 5, "Down", 24.00, 10, "00789");
        product[5] = new CD( 6, "God Forbid" , 10.00, 10, "00712");
        product[6] = new CD( 7, "Black Label Society" , 16.00, 10, "00458" );
        product[7] = new CD( 8, "Saint Vitus" , 15.00, 10, "00889");
        product[8] = new CD( 9, "Clearlight" , 15.00, 10, "00897");
        product[9] = new CD( 10, "Testament" , 15.00, 10, "00656");       
        //Sort elements in array in alphabetical order by product name
//        product[0].sortItems(product);
    final JButton firstBtn = new JButton("First"); // first button
final JButton prevBtn = new JButton("Previous"); // previous button
final JButton nextBtn = new JButton("Next"); // next button
final JButton lastBtn = new JButton("Last"); // last button
final JLabel label; // logo
final JTextArea textArea; // text area for product list
final JPanel buttonJPanel; // panel to hold buttons
//JLabel constructor for logo
Icon logo = new ImageIcon("C:/logo.jpg"); // load logo
label = new JLabel(logo); // create logo label
label.setToolTipText("Company Logo"); // create tooltip
    private void showGUI() {
        JLabel l;
        JButton b;
        fields = new JTextField[9];
        JComboBox combo = new JComboBox();
        for(int j = 0; j < product.length; j++)
            combo.addItem(product[j].getName());
        combo.addActionListener(this);
        JFrame f = new JFrame("InventoryGUI");
        Container cp = f.getContentPane();
        cp.setLayout(new GridBagLayout());
        cp.setBackground(UIManager.getColor("control"));
        GridBagConstraints c = new GridBagConstraints();
        c.gridx = 0;
        c.gridy = GridBagConstraints.RELATIVE;
        c.gridwidth = 1;
        c.gridheight = 1;
        c.insets = new Insets(2, 2, 2, 2);
        c.anchor = GridBagConstraints.EAST;
        cp.add(l = new JLabel("Item Number:", SwingConstants.CENTER), c);   l.setDisplayedMnemonic('a');
        cp.add(l = new JLabel("Item Name:", SwingConstants.CENTER), c);    l.setDisplayedMnemonic('b');
        cp.add(l = new JLabel("Number of Units in Stock:", SwingConstants.CENTER), c);   l.setDisplayedMnemonic('c');
        cp.add(l = new JLabel("Price per Unit: $", SwingConstants.CENTER), c);       l.setDisplayedMnemonic('d');
        cp.add(l = new JLabel("Total cost of This Item: $", SwingConstants.CENTER), c);   l.setDisplayedMnemonic('e');
        cp.add(l = new JLabel("Total Value of All Merchandise in Inventory: $",
                               SwingConstants.CENTER), c);   l.setDisplayedMnemonic('f');
        cp.add(l = new JLabel("Item Code:", SwingConstants.CENTER), c);   l.setDisplayedMnemonic('g');
        cp.add(l = new JLabel("Product Restocking Fee: $", SwingConstants.CENTER), c);  l.setDisplayedMnemonic('h');
        cp.add(combo, c);
        c.gridx = 1;
        c.gridy = 0;
        c.weightx = 1.0;
        c.fill = GridBagConstraints.HORIZONTAL;
        c.anchor = GridBagConstraints.CENTER;
        cp.add(fields[0] = new JTextField(), c);
        fields[0].setFocusAccelerator('a');
        c.gridx = 1;
        c.gridy = GridBagConstraints.RELATIVE;
        cp.add(fields[1] = new JTextField(), c);         fields[1].setFocusAccelerator('b');
        cp.add(fields[2] = new JTextField(), c);         fields[2].setFocusAccelerator('c');
        cp.add(fields[3] = new JTextField(), c);         fields[3].setFocusAccelerator('d');
        cp.add(fields[4] = new JTextField(), c);         fields[4].setFocusAccelerator('e');
        cp.add(fields[5] = new JTextField(), c);         fields[5].setFocusAccelerator('f');
        cp.add(fields[6] = new JTextField(), c);         fields[6].setFocusAccelerator('g');
        cp.add(fields[7] = new JTextField(), c);         fields[7].setFocusAccelerator('h');
        cp.add(fields[8] = new JTextField(), c);         fields[8].setFocusAccelerator('i');
        c.weightx = 0.0;
        c.fill = GridBagConstraints.NONE;
        cp.add(b = new JButton("OK"), c);
        cp.add(b = new JButton("First"),c); // set up panel
        cp.add(b = new JButton("Prev"),c);
        cp.add(b = new JButton("Next"),c);
        cp.add(b = new JButton("Last"),c);
        b.setMnemonic('o');
        f.pack();
        f.addWindowListener(new WindowAdapter()
            public void windowClosing(WindowEvent evt)
                System.exit(0);
        f.setVisible(true);
    private void populateFields(int index) {
        CD cd = product[index];
        fields[0].setText(Long.toString(cd.getNumberCode()));
        fields[1].setText(cd.getName());
        fields[2].setText(Long.toString(cd.getUnits()));
        fields[3].setText(Double.toString(cd.getPrice()));
        fields[4].setText(Double.toString(cd.getSum()));
        fields[5].setText(Double.toString(cd.totalAllInventory(product)));
        fields[6].setText(cd.getCode());
        fields[7].setText(Double.toString(cd.getSum()*.05));       
class CD {
    int itemNumber;
    String name;
    int units;
    double price;
    String itemCode;
    public CD(int n, String name, double price, int units, String itemCo) {
        itemNumber = n;
        this.name = name;
        this.price = price;
        this.units = units;
        itemCode = itemCo;
    public int getNumberCode() { return itemNumber; }
    public String getName() { return name; }
    public int getUnits() { return units; }
    public double getPrice() { return price; }
    public double getSum() { return units*price; }
    public String getCode() { return itemCode; }
    public double totalAllInventory(CD[] cds) {
        double total = 0;
        for(int j = 0; j < cds.length; j++)
            total += cds[j].getSum();
        return total;
public class InventoryI {
     String productnumber;
     String name;
     int numberofunits;
     double priceperunit;
        String itemcode;
     // Create a new instance of Inventory
     // main constructor for the class
     public InventoryI(String Item_Number, String Item_Name, int Items_in_Stock,
               double Item_Price, String Item_Code) {
          productnumber = Item_Number;
          name = Item_Name;
          numberofunits = Items_in_Stock;
          priceperunit = Item_Price;
                itemcode = Item_Code;
     public void setItemName(String Item_Name) {
     // sets the items name
          name = Item_Name;
     public void setItemCode(String Item_Code) {
     // sets the items name
          itemcode = Item_Code;
        public void setItemNumber(String Item_Number) { // Sets the Product =Number
     // for the item
          productnumber = Item_Number;
     public void setItemsInStock(int Items_in_Stock) { // sets the =number of
     // units in stock
          numberofunits = Items_in_Stock;
     public void setItemPrice(double Item_Price) { // sets the price of =the
     // item
          priceperunit = Item_Price;
        public String getItemName() { // returns the Product Name of this item
          return name;
      public String getItemCode() { // returns the Product Name of this item
          return itemcode;
        public String getItemNumber() { // returns the Product Number of the =item
          return productnumber;
     public int getItemsInStock() { // returns how many units are in stock
          return numberofunits;
     public double getItemPrice() { // returns the price of the item
          return priceperunit;
     public double getInventoryIValue() { // returns the total value of =the stock
     // for this item
          return priceperunit * numberofunits;
     public static double getTotalValueOfAllInventory(InventoryI [] inv) {
             double tot = 0.0;
          for(int i = 0; i < inv.length; i++)  
               tot += inv.getInventoryIValue();
          return tot;
     public static InventoryI[] sort(InventoryI [] inventory)
          InventoryI temp[] = new InventoryI[1];
          //sorting the array using Bubble Sort
          for(int j = 0; j < inventory.length - 1; j++)
          for(int k = 0; k < inventory.length - 1; k++)
          if(inventory[k].getItemName().compareToIgnoreCase(inventory[k+1].getItemName()) > 0)
          temp[0] = inventory[k];
          inventory[k] = inventory[k+1];
          inventory[k+1] = temp[0];
          }//end if
          }//end for loop
          }//end for loop
          return inventory;
     public String toString()
          StringBuffer sb = new StringBuffer();
          sb.append("CD Title: \t").append(name).append("\n");
sb.append("Item Code: \t").append(itemcode).append("\n");
          sb.append("Item #:      \t").append(productnumber).append("\n");
          sb.append("Number in stock:\t").append(numberofunits).append("\n");
          sb.append("Price: \t").append(String.format("$%.2f%n", priceperunit));
          sb.append("Inventory Value:\t").append(String.format("$%.2f%n", this.getInventoryIValue()));
          return sb.toString();
Thank you in advance for any help.

Answer 1

    public String toString() {
        return(
             "CD Title        :\t"+name+"\n"
            +"Item Code       :\t"+itemcode+"\n"
            +"Item #          :\t"+productnumber+"\n"
            +"Number in stock :\t"+numberofunits+"\n"
            +"Price           :\t"+String.format("$%.2f%n", priceperunit)
            +"Inventory Value :\t"+String.format("$%.2f%n", this.getInventoryIValue()
    }There's some help. Have fun appreciating it.
Well... you did ask the silliest question of all. "Please fix my homework." And you forgot the please.
keith.