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);
	}
}