BankDatabase

public class BankDatabase
{
    private Account[] accounts;

    public BankDatabase()
    {
       accounts = new Account[ 2 ];
       accounts[ 0 ] = new Account( 12345, 54321, 1000.0, 1200.0 );
       accounts[ 1 ] = new Account( 98765, 56789, 200.0, 200.0 );
    }

    private Account getAccount(int accountNumber)
    {
        for ( Account currentAccount : accounts)
        {
            if(currentAccount.getAccountNumber() == accountNumber)
            return currentAccount;
        }
        return null;
    }

    public boolean authenticateUser(int userAccountNumber, int userPIN)
    {
        Account userAccount = getAccount(userAccountNumber);

        if(userAccount != null) return userAccount.validatePIN(userPIN);

        else return false;
    }

    public double getAvailableBalance(int userAccountNumber)
    {
        return 0f;
    }

    public double getTotalBalance(int userAccountNumber)
    {
        return getAccount(userAccountNumber).getTotalBalance();

    }

    public void credit(int userAccountNumber, double amount)
    {
        getAccount(userAccountNumber).credit(amount);
    }

    public void debit(int userAccountNumber, double amount)
    {
        getAccount(userAccountNumber).debit(amount);
    }

}