Class Withdraw

public class Withdraw extends Transaction
{
 private int amount;
 private Keypad keypad;
 private CashDispenser cashDispenser;

 private final static int CANCELED = 6;

 public Withdraw(int userAccountNumber, Screen atmScreen, BankDatabase atmBankDatabase, Keypad atmKeypad, CashDispenser atmCashDispenser)
 {
 super( userAccountNumber, atmScreen, atmBankDatabase );

 keypad = atmKeypad;
 cashDispenser = atmCashDispenser;
 }

 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("\nUang anda telah" + " dikeluarkan. Silahkan ambil uang anda.");
 }

 else
 {
 screen.displayMessageLine("\nUang tidak cukup tersedia di ATM." + "\n\nSilakan pilih jumlah yang lebih kecil.");
 }
 }

 else
 {
 screen.displayMessageLine("\nUang di akun anda tidak mencukupi." + "\n\nSilakan pilih jumlah yang lebih kecil.");
 }
 }

 else
 {
 screen.displayMessageLine( "\nMembatalkan Transaksi..." );
 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( "\nMenu Penarikan:" );
 screen.displayMessageLine( "1 - $20" );
 screen.displayMessageLine( "2 - $40" );
 screen.displayMessageLine( "3 - $60" );
 screen.displayMessageLine( "4 - $100" );
 screen.displayMessageLine( "5 - $200" );
 screen.displayMessageLine( "6 - Membatalkan Transaksi" );
 screen.displayMessage( "\nPilih menu penarikan: " );

 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("\nPilihan anda salah. Silahkan coba lagi.");
 }
 }

 return userChoice;
 }
}