Please Help! I need to change this from a paperclip logo to a book logo

[keekee]

My code runs fine, but I keep getting this error message: I would like to change this logo from a paperclip logo to a book logo, my code is under the error. Can you tell me what's wrong and how to change it to a book logo?
Uncaught error fetching image:
java.lang.NullPointerException
at sun.awt.image.URLImageSource.getConnection(URLImageSource.java:99)
at sun.awt.image.URLImageSource.getDecoder(URLImageSource.java:113)
at sun.awt.image.InputStreamImageSource.doFetch(InputStreamImageSource.j
ava:240)
at sun.awt.image.ImageFetcher.fetchloop(ImageFetcher.java:172)
at sun.awt.image.ImageFetcher.run(ImageFetcher.java:136)

import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.FlowLayout;
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.Toolkit;
import java.awt.Dimension;
import java.net.URL;

class Inventory {

String number; // item number
String name; // item name
int quantity; // quanity of item
double price; // item price

public Inventory(String Number, String Name, int Quantity, double Price)
{
number = Number;
name = Name;
quantity = Quantity;
price = Price;
}
//Method set & get product name
public void setName(String Name)
{
name = Name;
}
public String getName()
{
return name;
}

//Method set & get product number
public void setNumber(String Number)
{
number = Number;
}
public String getNumber()
{
return number;
}

//Method set & get quantity of product
public void setQuantity(int Quantity)
{
quantity = Quantity;
}
public int getQuantity()
{
return quantity;
}

//Method set & get product price
public void setPrice(double Price)
{
price = Price;
}
public double getPrice()
{
return price;
}

//Method calculate inventory value
public double getInventoryValue()
{
return price * quantity;
}

public String toString()
{
return "Item Name: "+name + "\nItem Number: "+number+"\nItem Price: $"+price+"\nQuantity in Stock: "+quantity + "\nInventory Value: $"+getInventoryValue();
}
} // end Inventory Class

class Product extends Inventory {

String brand; // Subclass to add type of book
double restockFee; // Restock fee added to the inventory value

// constructor initializes inventory information
public Product(String brand, double restockFee, String Number, String Name, int Quantity, double Price)
{
super(Number, Name, Quantity, Price);
this.brand = brand;
this.restockFee = restockFee;
}

public Product(String brand, String Number, String Name, int Quantity, double Price)
{
super(Number, Name, Quantity, Price);
this.brand = brand;
// default 5% restocking fee
this.restockFee = 0.05;
}

public void setBrandName(String brand)
{
brand = brand;
}
public String getBrandName()
{
return brand;
}

public double getRestockFee() // Figures out restocking fee
{
return super.getInventoryValue() * restockFee;
}

public double getInventoryValue() // Total inventory value plus restocking fee
{
return super.getInventoryValue() + (super.getInventoryValue() * restockFee);
}

public String toString()
{
StringBuffer sb = new StringBuffer ("\nBrand: ").append(brand).append("\n");
sb.append (super.toString());

return sb.toString();
}

} // End Product Class

class Inventory2
{

// store book inventory
Product[] inventory;

// store number of books added to inventory
int number_of_products_in_inventory = 0;

// create an inventory capable of holding maximum_number_of_products different products
public Inventory2(int maximum_number_of_products)
{
inventory = new Product[maximum_number_of_products];
}

// add the books to the end of the inventory
public void addProduct(Product products_to_add_to_inventory)
{
inventory[number_of_products_in_inventory] = products_to_add_to_inventory;
number_of_products_in_inventory++;
}
// return the number of products in the inventory
public Product getProduct(int index)
{
return inventory[index];
}

// return number of products in inventory
public int getSize()
{
return number_of_products_in_inventory;
}

// run through all the books in the inventory, and add up their value.
// this includes the restocking fee
public double getTotalValueOfAllInventory()
{
double tot = 0.00;

for(int i = 0; i < number_of_products_in_inventory; i++)
{
tot += inventory[i].getInventoryValue();
}
return tot;
}

// sort the books in the inventory by name
public void sortInventory2()
{
// Sorting Inventory Information
for(int j = 0; j < number_of_products_in_inventory - 1; j++)
{
for(int k = 0; k < number_of_products_in_inventory - 1; k++)
{
if(inventory[k].getName().compareToIgnoreCase(inventory[k+1].getName()) > 0)
{
Product temp = inventory[k];
inventory[k] = inventory[k+1];
inventory[k+1] = temp;
}
}
}
}
} // End Inventory2 class

public class Inventory5 extends JFrame
{

//create inventory for the books
Inventory2 ProductInventory2;

// index in the supply inventory of the currently displayed books. starts at 0, goes to the number of books in the inventory - 1
int index = 0;

// GUI elements to display currently selected books information
private final JLabel nameLabel = new JLabel(" Product Name: ");
private JTextField nameText;

private final JLabel numberLabel = new JLabel(" Product Number: ");
private JTextField numberText;

private final JLabel brandLabel = new JLabel(" Brand: ");
private JTextField brandText;

private final JLabel priceLabel = new JLabel(" Price: ");
private JTextField priceText;

private final JLabel quantityLabel = new JLabel(" Quantity: ");
private JTextField quantityText;

private final JLabel valueLabel = new JLabel(" Value: ");
private JTextField valueText;

private final JLabel restockFeeLabel = new JLabel(" Restocking Fee: ");
private JTextField restockFeeText;

private final JLabel totalValueLabel = new JLabel(" Inventory Total: ");
private JLabel totalValueText;

// go to the next item in the list
private Action nextAction = new AbstractAction("Next") {
public void actionPerformed(ActionEvent evt) {

// check to see if there is a next book
if (index == ProductInventory2.getSize() - 1) {
// if we're at the book in the list, then we can't go any further
// go to front of list
index = 0;
} else {
index++;
}

repaint();
}
};
private JButton nextButton = new JButton(nextAction);

// go to previous book in the list
private Action previousAction = new AbstractAction("Previous") {
public void actionPerformed(ActionEvent evt) {

// if we're at the first book, then go to the last book in the list
if (index == 0) {
index = ProductInventory2.getSize() - 1;
} else {
index--;
}

repaint();
}
};
private JButton previousButton = new JButton(previousAction);

// go to the first book in list
private Action firstAction = new AbstractAction("First") {
public void actionPerformed(ActionEvent evt) {

index = 0;

repaint();
}
};
private JButton firstButton = new JButton(firstAction);

// go to the last book in list
private Action lastAction = new AbstractAction("Last") {
public void actionPerformed(ActionEvent evt) {

index = ProductInventory2.getSize() - 1;

repaint();
}
};
private JButton lastButton = new JButton(lastAction);

public void addProductToInventory2(Product temp)
{
ProductInventory2.addProduct(temp);
repaint();
}
public void sortProductInventory2()
{
ProductInventory2.sortInventory2();
repaint();
}

public Inventory5(int maximum_number_of_products)
{
// create the inventory object that will hold the book information
ProductInventory2 = new Inventory2(maximum_number_of_products);

// setup the GUI
// add the next book button to the top of the GUI
// setup panel to collect buttons in FlowLayout
JPanel buttonPanel = new JPanel();
buttonPanel.add(firstButton);
buttonPanel.add(previousButton);
buttonPanel.add(nextButton);
buttonPanel.add(lastButton);
getContentPane().add(buttonPanel, BorderLayout.NORTH);

// setup logo for GUI
URL url = this.getClass().getResource("logo.jpg");
Image img = Toolkit.getDefaultToolkit().getImage(url);
// scale image to fit in GUI
Image scaledImage = img.getScaledInstance(205, 300, Image.SCALE_AREA_AVERAGING);
// create JLabel with image as the label's Icon
Icon logoIcon = new ImageIcon(scaledImage);
JLabel companyLogoLabel = new JLabel(logoIcon);

// add logo to GUI
getContentPane().add(companyLogoLabel, BorderLayout.WEST);

// book information
// setup a panel to collect all the components.
JPanel centerPanel = new JPanel(new GridLayout(8, 2, 0, 4));

centerPanel.add(nameLabel);
nameText = new JTextField("");
nameText.setEditable(false);
centerPanel.add(nameText);

centerPanel.add(numberLabel);
numberText = new JTextField("");
numberText.setEditable(false);
centerPanel.add(numberText);

centerPanel.add(brandLabel);
brandText = new JTextField("");
brandText.setEditable(false);
centerPanel.add(brandText);

centerPanel.add(priceLabel);
priceText = new JTextField("");
priceText.setEditable(false);
centerPanel.add(priceText);

centerPanel.add(quantityLabel);
quantityText = new JTextField("");
quantityText.setEditable(false);
centerPanel.add(quantityText);

centerPanel.add(valueLabel);
valueText = new JTextField("");
valueText.setEditable(false);
centerPanel.add(valueText);

centerPanel.add(restockFeeLabel);
restockFeeText = new JTextField("");
restockFeeText.setEditable(false);
centerPanel.add(restockFeeText);

// add inventory information to panel
centerPanel.add(totalValueLabel);
totalValueText = new JLabel("");
centerPanel.add(totalValueText);

// add the panel to the center of the GUI's window
getContentPane().add(centerPanel, BorderLayout.CENTER);

repaint();
}

// repaint the GUI with new Product information
public void repaint() {

Product temp = ProductInventory2.getProduct(index);

if (temp != null) {
nameText.setText( temp.getName() );
numberText.setText( ""+temp.getNumber() );
brandText.setText( temp.getBrandName() );
priceText.setText( String.format("$%.2f", temp.getPrice()) );
quantityText.setText( ""+temp.getQuantity() );
valueText.setText( String.format("$%.2f", temp.getPrice() * temp.getQuantity() ) );
restockFeeText.setText( String.format("$%.2f", temp.getRestockFee() ) );
}

totalValueText.setText( String.format("$%.2f", ProductInventory2.getTotalValueOfAllInventory() ) );

}

public static void main(String args[])
{

// create new GUI object that will hold a maximum of 6 books
Inventory5 Product_GUI = new Inventory5 (6);

// Add the office supplies to the inventory
Product_GUI.addProductToInventory2(new Product("HardBack", "1","Harry Potter" , 27, 15.99));
Product_GUI.addProductToInventory2(new Product("HardBack", "2","Eragon" , 15, 10.99));
Product_GUI.addProductToInventory2(new Product("SoftBack", "3","Letters to my Daughter", 14, 24.99));
Product_GUI.addProductToInventory2(new Product("HardBack", "4","Twlight" , 20, 22.99));
Product_GUI.addProductToInventory2(new Product("SoftBack", "5", "Eldest", 35, 11.99));
Product_GUI.addProductToInventory2(new Product("SoftBack", "6", "The Da Vinci Code", 24, 9.00));

// sort the books by name
Product_GUI.sortProductInventory2();

// Get GUI to show on screen
Product_GUI.setDefaultCloseOperation( EXIT_ON_CLOSE );
Product_GUI.pack();
Product_GUI.setSize(700, 350);
Product_GUI.setResizable(false);
Product_GUI.setLocationRelativeTo( null );
Product_GUI.setVisible(true);

return;

}
} // End Inventory5 class

[masijade]

It probably means that the image you're trying to load doesn't exist. To change which image you're showing you need only change the image file you're loading, of course.