bank

Class Account

java.lang.Object

bank.Account

Direct Known Subclasses:

OfflineAccountProxy, PermanentAccount

public abstract class Account
extends java.lang.Object

Abstract superclass of all representatives of accounts, i.e. both the permanent account objects AccountData and the temporary proxy objects OfflineAccountProxy. This class provides infrastructure for storing lists of transactions and some standard implementations of account methods.

Field Summary

Fields

Modifier and Type	Field and Description
int	accountNumber Account number of the account represented by this object TODO: replace public with private; this seems to be a problem with the JML-DL translation (accountNumber is not visible in JML specs for subclasses if the Java visibility is private)
TransactionList	transactions A list of transactions in which the most recent transaction is the first element

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Account(int accountNumber)

Method Summary

Methods

Modifier and Type	Method and Description
abstract int	accountBalance()
protected void	addTransaction(Transaction trance) Add a transaction trance to the list of stored transaction
abstract boolean	balanceIsAccessible()
int	checkAndWithdraw(int amount) Try to withdraw amount from the account with checking whether this is possible, return the amount of money that is given out
protected void	flushTransactions() Remove all transactions that have been pushed using addTransaction
int	getAccountNumber()
protected TransactionList	getTransactions() Get all transactions that have been performed for this account.
abstract boolean	newWithdrawalIsPossible(int amount) Determine whether a certain amount of money may be withdrawn.
abstract void	requestStatement() Request a printed account statement.
protected java.lang.String	transactionListToString() Helper method, used by the two subclasses of this class for implementing toString
abstract void	withdraw(int amount) Withdraw amount from the account

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

accountNumber

public final int accountNumber

Account number of the account represented by this object TODO: replace public with private; this seems to be a problem with the JML-DL translation (accountNumber is not visible in JML specs for subclasses if the Java visibility is private)

transactions

public TransactionList transactions

A list of transactions in which the most recent transaction is the first element

Constructor Detail

Account

protected Account(int accountNumber)

Method Detail

withdraw

public abstract void withdraw(int amount)

Withdraw amount from the account

Parameters:

amount - the amount to be withdrawn

checkAndWithdraw

public int checkAndWithdraw(int amount)

Try to withdraw amount from the account with checking whether this is possible, return the amount of money that is given out

Parameters:

amount - the amount to be withdrawn

Returns:

amount if the withdrawal was successful, 0 otherwise

requestStatement

public abstract void requestStatement()

Request a printed account statement. This request may fail at a late point if the account is offline, in this case nothing happens (the customer does not receive anything). For this reason the method does not have any preconditions

balanceIsAccessible

public abstract boolean balanceIsAccessible()

Returns:

true iff the balance of this account can be determined (not possible for the offline situation)

accountBalance

public abstract int accountBalance()

Returns:

the balance of this account

newWithdrawalIsPossible

public abstract boolean newWithdrawalIsPossible(int amount)

Determine whether a certain amount of money may be withdrawn. Using method PermanentAccount.withdraw(int,int) it is possible to circumvent this check, which is necessary because for offline withdrawals the balance cannot be accessed and checked

Parameters:

amount - the amount of money requested

Returns:

true iff amount can be withdrawn from the account

getAccountNumber

public int getAccountNumber()

Returns:

the account number of the account represented by this object

addTransaction

protected void addTransaction(Transaction trance)

Add a transaction trance to the list of stored transaction

Parameters:

trance - the transaction to be added

getTransactions

protected TransactionList getTransactions()

Get all transactions that have been performed for this account. In the resulting list, the most recent transaction is the first element.

Returns:

the list of transactions

flushTransactions

protected void flushTransactions()

Remove all transactions that have been pushed using addTransaction

transactionListToString

protected java.lang.String transactionListToString()

Helper method, used by the two subclasses of this class for implementing toString

Returns:

the linearised result of getTransactions