Eduardo M. Breijo Baullosa May 2, Assignment 17. Report

Size: px

Start display at page:

Download "Eduardo M. Breijo Baullosa May 2, Assignment 17. Report"

Ada Bradford
5 years ago
Views:

1 Eduardo M. Breijo Baullosa May 2, 2012 Cesar I. Cruz ICOM4015 Assignment 17 Report The Automated teller machine is a computer that allows the interaction between bank account information and its respective customers. From the customer side of view all that a teller does is display a menu, authenticate credentials (user and pin), gives the user the choice to either make a deposit or make a withdraw, also the option to display the current balance. To implement all this basic functions using OOP the distribution of classes will be as follows (using CRC method): CRC Cards: Customer Constructs customers with customer number and PIN Match the number and PIN Get accounts Read customer numbers and pins Find customer according to PIN Bank Customer BankAccount Make transactions Deposit money in an account Withdraw money in an account Get the current balance of the account Manage state Select and find customer Select account Execute transaction ATM Customer Bank BankAccount ATMSimulator Show a text- based simulation of ATM Read customer number and PIN ATM Bank

2 Make possible transactions ATMViewer Show graphical interface simulation of ATM Construct ATM frame Construct and add components Display the components of ATM Add actions to each button Simulate a key pad to enter numbers Gets value entered by the user Make a text field as a log ATMFrame KeyPad JFrame JPanel JTextField

3 ATM UML Design

4 Report of the State Diagram for the ATM Class The State Diagram of the ATM class present four states, these are; START, PIN, ACCOUNT and TRANSACT states. Those states represent a condition for each event occurred in the ATM class that handles correctly each part of the current machine state. As we can see, there s always an initial state where the users starts by entering the customer ID, then entering the PIN number, then selecting the account and after complete or cancel a transaction, it always goes back to the ACCOUNT state again to change the accounts, so after exit accounts, it always return to that initial state, that is; START state. In addition, if the user enter a wrong customer number or PIN number, the ATM will return back to the initial state because could not find matches with those numbers. Finally, these states are only a way to facilitate the ATM program to know in what part it is found and also to perform properly.

5 ATM à An ATM that accesses a bank public static final int CHECKING; public static final int SAVINGS; private int state; private int customernumber; private Customer currentcustomer; private BankAccount currentaccount; private Bank thebank; public static final int START; public static final int PIN; public static final int ACCOUNT; public static final int TRANSACT; public ATM(Bank abank) o Constructs an ATM for a given bank. abank the bank to which this ATM connects Methods: public void reset() o Reset the ATM to the initial state public void setcustomernumber(int number) o Sets the current customer number and sets state to PIN. (Precondition: state is START) number the customer number public void selectcustomer(int pin) o Finds customer in bank. If found, sets state to ACCOUNT, else to START. (Precondition: state is PIN) pin the PIN of the current customer public void selectaccount(int account) o Sets current account to checking or savings. Sets state to TRANSACT. (Precondition: state is ACCOUNT or TRANSACT) account one of CHECKING or SAVINGS public void withdraw(double value) o Withdraws amount from current account. (Precondition: state is TRANSACT) value the amount to withdraw public void deposit(double value) o Deposits amount to current account. (Precondition: state is TRANSACT) value the amount to deposit public double getbalance() o Gets the balance of the current account. (Precondition: state is TRANSACT) the balance public void back() o Moves back to the previous state

6 public int getstate() o Gets the current state of this ATM the current state Bank à A bank contains customers with bank accounts. private ArrayList<Customer> customers; public Bank() o Constructs a bank with no customers. Methods: public void readcustomers(string filename) o Reads the customer numbers and pins and initializes the bank accounts. filename the name of the customer file public void addcustomer(customer c) o Adds a customer to the bank. c the customer to add. public Customer findcustomer(int anumber, int apin) o Finds a customer in the bank. anumber a customer number apin a personal identification number the matching customer, or null if no customer matches Customer à A bank customer with a checking and a savings account private int customernumber; private int pin; private BankAccount checkingaccount; private BankAccount savingsaccount; public Customer(int anumber, int apin) o Constructs a customer with a given number and PIN. anumber the customer number apin the personal identification number Methods: public boolean match(int anumber, int apin) o Tests if this customer matches a customer number and PIN. anumber a customer number apin a personal identification number true if the customer number and PIN match

7 public BankAccount getcheckingaccount() o Gets the checking account of this customer. the checking account public BankAccount getsavingsaccount() o Gets the savings account of this customer. the checking account ATMViewer à A graphical simulation of an automatic teller machine. ATM theatm; ATMFrame à A frame displaying the components of an ATM. private static final int FRAME_WIDTH = 300; private static final int FRAME_HEIGHT = 300; private JButton abutton; private JButton bbutton; private JButton cbutton; private KeyPad pad; private JTextArea display; private ATM theatm; public ATMFrame(ATM anatm) o Constructs the user interface of the ATM frame Methods: public void showstate() o Updates display message public void actionperformed(actionevent event) o Perform an action for each button KeyPad à A component that lets the user enter a number, using a keypad labeled with digits. private JPanel buttonpanel; private JButton clearbutton; private JTextField display; public KeyPad() o Construct the keypad panel

8 Methods: private void addbutton(final String label) o Adds a button to the button panel. label the button label private double getvalue() o Gets the value that the user entered. the value in the text field of the keypad public void clear() o Clears the display Upon copying the code, several thing had to be taken into consideration, first off the classes BankAccount and SavingsAccount had to be added, they where not included in the specific implementation of this ATM, also the BankAccount class had to be modified to include a constructor without parameters. The implementation as described in the book required the use of files. After fixing all the compiler errors visible and running the program, the files where not found, for this problem. The major problem at runtime was to handle the file not found exceptions, in general these problems were not that complicated, for this we came up with two basic solutions, either adding a file writer to the try/catch statement or manually creating a.txt file with a couple of bank accounts and added to the source folder of the program, we chose the latter. To extend the functionality of this program we could make it resemble an online bank account system. By this we mean adding extra features apart that would set this program apart from normal atm programs. Amongst these features: The ability to create different types of bank accounts. The user can choose to create a savings account or a checking account and the specifics for each of the accounts, interest rates, minimum balance charges, and a different set of parameters. The ability to interchange funds from one account to the next and pay bills. A feature that will export a file containing an invoice of the transactions that took place, along with the current balance of the accounts. All of these features will work interactively with the user by enhancing certain parameters of the GUI and adding a few more classes.

Simulating an Automatic Teller Machine

Simulating an Automatic Teller Machine WE1 Worked Example 12.1 Simulating an Automatic Teller Machine Tom Horyn/iStockpho In this Worked Example, we apply the object-oriented design methodology to the