Java coding Inventory Program Part 5

[spopivich]

This is my first class to java programming (java coding is all new to me) and I have my part 5 assignment due today and I am absolutely clueless to why I am getting this error but I know it has to do something with my image I just do not know how to fix my problem. I was able to compile successfully but it came back with an error message when I go to run the program. What the message reads:
Uncaught error fetching image:
java.lang.NullPointerException
at sun.awt.image.URLImageSouce.getConnection<URLImage Source.java:115>
at sun.awt.image.URLImageSource.getDecoder<URLImageSo urce.java:125>
at sun.awt.image.InputStreamImageSource.doFectch<Inpu tStreamImageSource.java:263>
at sun.awt.image.ImageFetcher.fectchloop<ImageFetcher .java:205>
at sun.awt.image.ImageFecther.run<ImageFetcher.java:1 69>

Not sure if all parts are needed that I have compiled. Here is the last part that I have compiled that gave me the error message.

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;
 
public class inventoryTest extends JFrame
{
 
//create inventory for the dvds
Inventory2 ProductInventory2;
 
// index in the supply inventory of the currently displayed dvd. starts at 0, goes to the number of dvds in the inventory - 1
int index = 0;
 
// GUI elements to display currently selected dvds information
private final JLabel nameLabel = new JLabel(" DVD 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 dvd in the list
private Action nextAction = new AbstractAction("Next") {
public void actionPerformed(ActionEvent evt) {
 
// check to see if there is a next dvd
if (index == ProductInventory2.getSize() - 1) {
// if we're at the last dvd in the list, then we can't go any further
// so go to the front of the list
index = 0;
} else {
index++;
}
 
repaint();
}
};
private JButton nextButton = new JButton(nextAction);
 
// go to the previous dvd in the list
private Action previousAction = new AbstractAction("Previous") {
public void actionPerformed(ActionEvent evt) {
 
// if we're at the first dvd, then go to the last dvd in the list
if (index == 0) {
index = ProductInventory2.getSize() - 1;
} else {
index--;
}
 
repaint();
}
};
private JButton previousButton = new JButton(previousAction);
 
// go to the first dvd in the 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 dvd in the 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(DVD temp)
{
ProductInventory2.addDVD(temp);
repaint();
}
public void sortProductInventory2()
{
ProductInventory2.sortInventory2();
repaint();
}
 
public inventoryTest(int maximum_number_of_dvd)
{
// create the inventory object that will hold the dvd information
ProductInventory2 = new Inventory2(maximum_number_of_dvd);
 
// setup the GUI
// add the next dvd button to the top of the GUI
// setup a panel to collect all the buttons in a FlowLayout
JPanel buttonPanel = new JPanel();
buttonPanel.add(firstButton);
buttonPanel.add(previousButton);
buttonPanel.add(nextButton);
buttonPanel.add(lastButton);
getContentPane().add(buttonPanel, BorderLayout.NORTH);
 
// setup the logo for the GUI
URL url = this.getClass().getResource("logo.jpg");
Image img = Toolkit.getDefaultToolkit().getImage(url);
// scale the image so that it'll fit in the GUI
Image scaledImage = img.getScaledInstance(205, 300, Image.SCALE_AREA_AVERAGING);
// create a JLabel with the image as the label's Icon
Icon logoIcon = new ImageIcon(scaledImage);
JLabel companyLogoLabel = new JLabel(logoIcon);
 
// add the logo to the GUI
getContentPane().add(companyLogoLabel, BorderLayout.WEST);
 
// product 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 the overall inventory information to the 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() {
 
DVD temp = ProductInventory2.getDVD(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 a new GUI object that will hold a maximum of 4 office supplies
inventoryTest DVD_GUI = new inventoryTest (4);
 
// Add the dvds to the inventory
DVD_GUI.addProductToInventory2(new DVD("Sony" , "101","Korn" , 20, 10.00));
DVD_GUI.addProductToInventory2(new DVD("BMG" , "201","TLC" , 20, 12.00));
DVD_GUI.addProductToInventory2(new DVD("Song", "301","Creed", 10, 13.00));
DVD_GUI.addProductToInventory2(new DVD("BMG", "401","Drake" , 15, 14.00));
 
// sort the dvd by name
DVD_GUI.sortProductInventory2();
 
// Get the GUI to show up on the screen
DVD_GUI.setDefaultCloseOperation( EXIT_ON_CLOSE );
DVD_GUI.pack();
DVD_GUI.setSize(700, 350);
DVD_GUI.setResizable(false);
DVD_GUI.setLocationRelativeTo( null );
DVD_GUI.setVisible(true);
 
return;
 
}
} // End inventoryTest class

[chaarmann]

I can see only GUI commands (Swing) inside the listed sourcecode. They cannot cause the error.
And I can see access to objects (like DVD_GUI) where the source code is missing, but that could lead to the error.
So just list the source code that calls URLImageSouce.getConnection().
Because there you must define a URL. And if you have given null instead of a valid URL, then it will crash when trying to open this connection with
url.openConnection() inside URLImageSouce.getConnection() method.