Withdrawal

public class Withdrawal extends Transaction
{
    private int amount;
    private CashDispenser cashDispenser;
    private Keypad keypad;
    private BankDatabase bankDatabase;

    private static final int CANCELED = 6;
    public Withdrawal(int userAccountNumber, Screen atmScreen, BankDatabase atmBankDatabase, Keypad atmKeypad, CashDispenser cashDispenser)
    {
        super(userAccountNumber, atmScreen, atmBankDatabase);

        keypad = atmKeypad;
        bankDatabase = atmBankDatabase;
    }

    @Override
    public void execute()
    {
        boolean cashDispensed = false;
        double availableBalance;

        BankDatabase bankDatabase = getBankDatabase();
        Screen screen = getScreen();

        do
        {
            amount = displayMenuOfAmounts();

            if(amount != CANCELED)
            {
                availableBalance = bankDatabase.getAvailableBalance(getAccountNumber());

                if(amount <= availableBalance)
                {
                    if(cashDispenser.isSufficientCashAvailable(amount))
                    {
                        bankDatabase.debit(getAccountNumber(), amount);

                        cashDispenser.dispenseCash(amount);
                        cashDispensed = true;
                        screen.displayMessageLine("\nYour cash has been " + "dispensed. Please take your cash now.");
                    }
                    else screen.displayMessageLine("\nInsufficient cash available in the ATM." + "\n\nPlease choose a smaller amount.");
                }
                else screen.displayMessageLine("\nInsufficient funds in your account." + "\n\nPlease choose a smaller amount.");
            }

            else
            {
                screen.displayMessageLine("Canceling transaction...");
                return;
            }
        } while(!cashDispensed);
    }

    private int displayMenuOfAmounts()
    {
         int userChoice = 0;
         Screen screen = getScreen();

         int[] amounts = {0, 20, 40, 60, 100, 200};

         while(userChoice == 0)
         {
             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");
             screen.displayMessage("\nChoose a withdrawal amount: ");

             int input = keypad.getInput();

             switch(input)
             {
                 case 1:
                 case 2:
                 case 3:
                 case 4:
                 case 5:
                    userChoice = amounts[input];
                    break;
                 case CANCELED:
                    userChoice = CANCELED;
                    break;
                 default:
                    screen.displayMessageLine("\nInvalid selection. Try again.");
             }
    }
    return userChoice;
}

}