Thread: Need help, please.

I am having problem with class extending a class. I have the classes needed wrote correctly but when writingthe test case there is an error message.

import javax.swing.JOptionPane;       public class ComputerTest { public void main(String args[]) { String message = "";	Computer computerArray[] = new Computer[5];   String dataArray[][] = {{"Laptop", "Sony", "Detroit", "599.99", "3", "15"}, {"Desktop", "Dell", "Houston", "1150.00", "5", "Inspiron"}, {"Desktop", "HP", "Los Angeles", "925.00", "2", "Pavilion"}, {"Laptop", "HP", "Los Angeles", "699.99", "12", "17"}, {"Laptop", "Apple", "Cupertino", "1399.00", "7", "13"}};   for(int i = 0; i < computerArray.length; i++) { if(dataArray[i][0].equals("Laptop"))	computerArray[i] = new Laptop(new Brand(dataArray[i][1], dataArray[i][2]),   Double.parseDouble(dataArray[i]   [3]),Integer.parseInt(dataArray[i][4]), Integer.parseInt(dataArray[i]   [5]));   else if(dataArray[i][0].equals("Desktop"))	computerArray[i] = new Desktop(new Brand(dataArray[i][1], dataArray[i][2]),   Double.parseDouble(dataArray[i]   [3]),Integer.parseInt(dataArray[i][4]), dataArray[i][5]); }   for(int i = 0; i < computerArray.length; i++) {   if (computerArray != null)	computerArray[i].calculateCharge(computerArray[i].getQuantity());       if (computerArray[i].getClass().getName().equals("Laptop"))	message += String.format("Laptop %s %.2f %s inches \n",	computerArray[i].getBrand(), computerArray[i].getTotalCharge(),  	computerArray[i].Laptop.getSize()); else if (computerArray[i].getClass().getName().equals("Desktop"))	message += String.format("Desktop %s %.2f %s \n",	computerArray[i].getBrand(), computerArray[i].getTotalCharge(),  	computerArray[i].getCategory());     } JOptionPane.showMessageDialog(null, message); } }

The error code looks like:

CommandPromptComputerTest.jpg

If more info is needed please let me know.

I decided to put up my classes in case there is something I am missing, although they compile fine.
The 2 errors in the code, one is supposed to come from Laptop and on from Desktop. I do not understand why though.
This one is Brand:

public class Brand { private String name; private String city;   public Brand() {	setName("");	setCity(""); }   public Brand(String name, String city) {	setName(name);	setCity(city); }   public void setName(String name) { this.name = name; }   public void setCity(String city) { this.city = city; }   public String getName() { return name; }   public String getCity() { return city; }   public String toString() { return("Name" + name + "City" + city); } }

This one is Computer:

public class Computer { private Brand brand; private double price; private int quantity; private double totalCharge;   public Computer() {	setBrand(new Brand());	setPrice(0.0);	setQuantity(0);   }   public Computer(Brand brand, double price, int quantity) {	setBrand(brand);	setPrice(price);	setQuantity(quantity);   }   public void setBrand(Brand brand) { this.brand = brand; }   public Brand getBrand() { return brand; }   public void setPrice(double price) { this.price = price; }   public void setQuantity(int quantity) { this.quantity = quantity; }   public void setTotalCharge(double totalCharge) { this.totalCharge = totalCharge; }       public double getPrice() { return price; }   public int getQuantity() { return quantity; }       public double getTotalCharge() { return totalCharge; }   public String toString() { return(brand.toString() + "Price" + price + "Quantity" + quantity); }   public void calculateCharge(double quantitySold) {	setTotalCharge(price * quantitySold);   }     }

This one is Laptop extends Computer:

public class Laptop extends Computer { private int size;   public Laptop() { super();	setSize(0); }   public Laptop(Brand brand, double price, int quantity, int size) { super(brand, price, quantity);	setSize(size); }   public void setSize(int size) { this.size = size; }   public int getSize() { return size; }   public String toString() { return(super.toString() + "Size" + size); } }

This last one is Desktop extends Computer:

public class Desktop extends Computer { private String category;   public Desktop() { super();	setCategory(""); }   public Desktop(Brand brand, double price, int quantity, String category) { super(brand, price, quantity);	setCategory(category); }   public void setCategory(String category) { this.category = category; }   public String getCategory() { return category; }   public String toString() { return(super.toString() + "Category" + category); } }