More Updates

Author: phongus

13 ATM Case Study/src/ATM.java

@@ -53,9 +53,9 @@ public void run()
 	//	attempts to authenticate user against database
 	private void authenticateUser()
 	{
-		screen.diplayMessage("\nPlease enter your account number: ");
+		screen.displayMessage("\nPlease enter your account number: ");
 		int accountNumber = keypad.getInput();	//	input account number
-		screen.diplayMessage("\nEnter your PIN: ");	//	prompt for PIN
+		screen.displayMessage("\nEnter your PIN: ");	//	prompt for PIN
 		int pin = keypad.getInput(); //	input PIN
 
 		//	set userAuthentigated to boolean value returned by the database

13 ATM Case Study/src/Screen.java

@@ -4,7 +4,7 @@
 public class Screen 
 {
 	//	display a message without a carriage return
-	public void diplayMessage(String message)
+	public void displayMessage(String message)
 	{
 		System.out.print(message);
 	}	//	end method displayMessage

13 ATM Case Study/src/Transaction.java

@@ -0,0 +1,39 @@
+//	Transaction.java
+//	Abstract superclass Transaction represents an ATM transaction
+
+public abstract class Transaction
+{
+	private int accountNumber;	//	indicates account involved
+	private Screen screen;	//	ATM's screen
+	private BankDatabase bankDatabase;	//	account info database
+	
+	//	Transaction constructor invoke by subclasses using super()
+	public Transaction(int userAccountNumber, Screen atmScreen,
+			BankDatabase atmBankDatabase)
+	{
+		accountNumber = userAccountNumber;
+		screen = atmScreen;
+		bankDatabase = atmBankDatabase;
+	}	//	end Transaction constructor
+	
+	//	return account number
+	public int getAccountNumber()
+	{
+		return accountNumber;
+	}	//	end method getAccountNumber
+	
+	//	return reference to screen
+	public Screen getScreen()
+	{
+		return screen;
+	}	//	end method getScreen
+	
+	//	return reference to bank database
+	public BankDatabase getBankDatabase()
+	{
+		return bankDatabase;
+	}	//	end method getBankDatabase
+	
+	//	perform the transaction (overridden by each subclass)
+	abstract public void execute();
+}

13 ATM Case Study/src/Withdrawal.java

@@ -0,0 +1,134 @@
+//	Withdrawal.java
+//	Represents a withdrawal ATM transaction
+
+public class Withdrawal extends Transaction
+{
+	private int amount;	//	amount to withdraw
+	private Keypad keypad;	//	reference to keypad
+	private CashDispenser cashDispenser;	//	reference to cash dispenser
+	
+	//	constant corresponding to menu option to cancel
+	private final static int CANCELED = 6;
+	
+	//	Withdrawal constructor
+	public Withdrawal(int userAccountNumber, Screen atmScreen,
+			BankDatabase atmBankDatabase, Keypad atmKeypad,
+			CashDispenser atmCashDispenser)
+	{
+		//	initialize superclass variables
+		super(userAccountNumber, atmScreen, atmBankDatabase);
+		
+		//	initialize references to keypad and cash dispenser
+		keypad = atmKeypad;
+		cashDispenser = atmCashDispenser;
+	}	//	end Withdrawal constructor
+	
+	//	perform transaction
+	@Override
+	public void execute()
+	{
+		boolean cashDispensed = false;	//	cash was not dispensed yet
+		double availableBalance; //	amount available for withdrawal
+		
+		//	get references to bank database and screen
+		BankDatabase bankDatabase = getBankDatabase();
+		Screen screen = getScreen();
+		
+		//	loop until cash is dispensed or the user cancels
+		do
+		{
+			//	obtain a chosen withdrawal amount from the user
+			amount = displayMenuOfAmounts();
+			
+			//	check whether user chose a withdrawal amount or canceled
+			if (amount != CANCELED)
+			{
+				//	get available balance of account involved
+				availableBalance =
+						bankDatabase.getAvailableBalance(getAccountNumber());
+				
+				//	check whether the user has enough money in the account
+				if (amount <= availableBalance)
+				{
+					//	check whethur the cash dispenser has enough money
+					if(cashDispenser.isSufficientCashAvailable(amount))
+					{
+						//	update the account involved to reflect the withdrawal
+						bankDatabase.debit(getAccountNumber(), amount);
+						
+						cashDispenser.dispenseCash(amount);	//	dispense cash
+						cashDispensed = true;	//	cash was dispensed
+						
+						//	instruct user to take cash
+						screen.displayMessageLine("\nYour cash has been" +
+						" dispensed. Please take your cash now.");
+					}	//	end if
+					else	//	not enough money available in user's accountscreen.displayMessageLine(
+						screen.displayMessageLine(
+								"\nInsufficient cash available in the ATM." +
+								"\n\nPlease choose a smaller amount.");
+				}	//	end if
+				else	//	not enough money available in user's account
+				{
+					screen.displayMessageLine(
+							"\nInsufficient funds in your account." +
+							"\n\nPlease choose a smaller amount.");
+				}	//	end else
+			}	//	end if
+			else	//	user chose cancel menu option
+			{
+				screen.displayMessageLine("\nCanceling transaction...");
+				return;	//	return to main menu because user canceled
+			}	//	end else
+		} while(!cashDispensed);
+		
+	}	//	end method execute
+	
+	//	display a menu of withdrawal amounts and the options to cancel;
+	//	return the chosen amount or 0 if the user chooses to cancel
+	private int displayMenuOfAmounts()
+	{
+		int userChoice = 0;	//	local variable to store return value
+		
+		Screen screen = getScreen();	//	get screen reference
+		
+		//	array of amounts to correspond to menu numbers
+		int[] amounts = { 0, 20, 40, 60, 100, 200 };
+		
+		//	loop while no valid choice has been made
+		while (userChoice == 0)
+		{
+			//	display the withdrawal menu
+			screen.displayMessageLine("\nWithdrawal Menu:");
+			screen.displayMessageLine("1 - $20");
+			screen.displayMessageLine("2 - $40");
+			screen.displayMessageLine("3 - $60");
+			screen.displayMessageLine("4 - $100");
+			screen.displayMessageLine("5 - $200");
+			screen.displayMessageLine("6 - Cancel transaction");
+			screen.displayMessage("\nChoose a withdrawal amount: ");
+			
+			int input = keypad.getInput();	//	get user input through keypad
+			
+			//	determine how to proceed based on the input value
+			switch (input)
+			{
+			case 1: //	if the user chose a withdrawal amount
+			case 2: //	(i.e., chose option 1, 2, 3, 4, or 5), return the
+			case 3: //	corresponding amount from amounts array
+			case 4:
+			case 5: 
+				userChoice = amounts[input];	//	save user's choice
+				break;
+			case CANCELED:	//	the user chose to cancel
+				userChoice = CANCELED; //	save user's choice
+				break;
+			default:	//	the user did not enter a value from 1-6
+				screen.displayMessageLine(
+						"\nInvalid selection. Try again.");
+			}	//	end switch
+		}	//	end while
+		
+		return userChoice;	//	return withdrawal amount or CANCELED
+	}	//	end method displayMenuOfAmounts
+}	//	end class Withdrawal