Modify assignment 5 so that instead of reading the data into an array, it is read into a linked list.  Add each new check or deposit to the end of the list.  You may follow the example below or create a separate class to handle the list.  Use the same data, applet and TextArea as before.  You should not have to change very much in your program for assignment 5.

/* An example of an applet that reads from a file, stores the information in a linked list, and then displays it in a TextArea on the applet. */

import java.io.*;
import java.text.*;
import java.awt.*;
import java.applet.Applet;

/* The applet creates the TextArea and the list.  It then reads in the list and displays it. */
public class OrdersLinked extends Applet
{
     private Panel panel;
     private Label areaLabel;
     private TextArea area;
     private OrderList list;
 
     public void init ()
     {
          panel = new Panel ();
          panel.setBackground (Color.cyan);
          areaLabel = new Label ("Order");
          area = new TextArea (10, 30);
          panel.add (areaLabel); panel.add (area);
          add (panel);
          list = new OrderList ();
          list.readOrders ();
          list.displayOrders (area);
          list.displayTotalCost (area);
     } // method init
} // class OrderFrame

/* The list class reads the data from the file and adds it to the end of a linked list.  It then displays the data and the total cost of the order. */
class OrderList
{
     private Order listHead = null, listRear = null;

     public void readOrders ()
     {
           try
          {
               BufferedReader orderFile = new BufferedReader (new InputStreamReader (new FileInputStream ("orderFile.txt")));
               String  name = orderFile.readLine ();
               while (name != null)
               {
                    Order order = new Order (name);
                    order.readOrder (orderFile);
                    addToEnd (order);
                    name = orderFile.readLine ();
               }
               orderFile.close ();
          }catch (IOException e) {System.out.println ("File Error");}
     } // method readOrders
 
      /* This method adds an order to the end of the linked list. */
      private void addToEnd (Order newOrder)
     {
          if (listHead == null)
          {
               listHead = newOrder;
               listRear = newOrder;
          }
          else
          {
               listRear.setNext (newOrder);
               listRear = newOrder;
          }
     } // method addToEnd
 
     /* A temporary node is used to go through the list and display the orders in the TextArea. */
     public void displayOrders (TextArea area)
     {
          Order tempNode = listHead;
          area.append ("Order List " + '\n' + '\n');
          while (tempNode != null)
          {
               tempNode.displayOrder (area);
               tempNode = tempNode.getNext ();
          }
     } // method displayOrders
 
      /* The total cost is computed by traveling through the list and adding in the price times the quantity of each order. */
     public void displayTotalCost (TextArea area)
     {
          Order tempNode = listHead;
          double total = 0;
          while (tempNode != null)
          {
               total += tempNode.getPrice () * tempNode.getQuantity ();
               tempNode = tempNode.getNext ();
          }
          area.append ("Total Cost = " + NumberFormat.getCurrencyInstance ().format (total) + '\n');
     } // method totalCost
} // class OrderList

/* The Order class contains both the data for each order as well as a pointer, next, to the next order in the list. */
class Order
{
     private String productName, id;
     private double price;
     private int quantity;
     private Order next = null;
 
     Order (String name) {productName = name;} // constructor
 
     protected Order getNext () { return next;}
     protected void setNext (Order newOrder) {next = newOrder;}
 
     protected double getPrice () {return price;}
     protected int getQuantity () {return quantity;}
 
     /* readOrder reads the data from the file and stores it in the order class. */
     public void readOrder (BufferedReader orderFile) throws IOException
     {
          id = orderFile.readLine ();
          price = Double.parseDouble (orderFile.readLine ());
          quantity = Integer.parseInt (orderFile.readLine ());
     } // method readOrder
 
     /* displayOrder appends each field in the class to the TextArea. */
     public void displayOrder (TextArea area)
     {
          area.append ("ID: " + id + '\n');
          area.append ("Name: " + productName + '\n');
          area.append ("Price: " + price + '\n');
          area.append ("Quantity: " + quantity + '\n' + '\n');
     } // method displayOrder
} // class Order