ATM program

[Totti]

Hi all,
I want to make an ATM program and a Bank server program, both
interacting for:
1 - an authentication (username, password)
2 - if the authetication passes i want to bring up a menu let us say
for withdrawal, deposit, checking the balance
3 - for each of these interactions i will do the proper behavior

what i need is some help on where to start, i need 2 apps running on
different computers, i ll open a port between them and make them talk.

i have the problem solved on paper but i d like to know where to
start, what coding is needed for such applications and what do i have
to bring into java to make it work (libraries,...)

(it is not a homework)

Thank you all

 

[Roedy Green]

i have the problem solved on paper but i d like to know where to
start, what coding is needed for such applications and what do i have
to bring into java to make it work (libraries,...)

I am not sure just how real you want to make this, but you could use
The Transporter to encrypt/sign the messages you send back and forth.
see http://mindprod.com/products.html#TRANSPORTER


Or you could use JCE. see http://mindprod.com/jgloss/jce.html

HTTPS/SSL might also fit into your scheme.

see http://mindprod.com/jgloss/ssl.html

 

[Chase Preuninger]

Well I did something similar but with a remote file system server.
What you basically have to do is set up your own mini-protocol which
has commands which can be written to the socket. It is easier this
way because you can have a model in which the request ALWAYS comes
from the client and the response ALWAYS comes from the server. For
example, say you wanted to log on, you would write the following
string to the socket.

"login johndoe,mypassword"

then the server would simply pares this and send the response

"accept" or "reject"

 

[Martin Gregorie]

To give you a start, assuming you want something reasonably realistic:
- the ATM is always the client and the bank's host is the server
- the comms protocol is message oriented, never character at a time
- AFAICR a message from the ATM always gets a single response message
from the server.
- ATM's are all Finite State Machines. Each screen corresponds to
a state. IIRC the server is stateless as far as the ATM protocol is
concerned.
- both ATM and host can detect a connection failure, even when nobody
is using the ATM.