osServer

GMIT, Operating Systems 1, Project, Semester 1 2016/17. MultiThreaded TCP Client-Server Banking system.

Project Brief:

Your project is to write a Multi-threaded TCP Server Application which allows multiple customers to update their bank accounts, make lodgements and withdrawals. The service should allow the users to:

1. Register with the system ( • Name • Address • Bank A/C Number • Username • Password )
2. Log-in to the banking system from the client application to the server application.
3. Change customer details.
4. Make Lodgements to their Bank Account.
5. Make Withdrawal from their Bank Account (Note: Each User has a credit limit of €1000).
6. View the last ten transactions on their bank account. Server Application Rules
7. The server application should not provide any service to a client application that can complete the authentication.
8. The server should hold a list of valid users of the service and a list of all the users previous transactions.
9. When the user logs in they should receive their current balance.

Design Decisions:

I tried to keep my design as close to what I know a real Bank application/ mobile banking app is like.

This infuenced me in parts, such as not asking the user to create their own account, I generate a unique account for them. As in a real banking application you would not be asked to create your own account number.

I used an arraylist that holds objects of type Account. Account is a class that holds member variables (Name,Address, etc) and a construtor to create Account objects. The accounts Array list was a simple lightway to hold all the accounts and used to itereate through the accounts and check information (i.e when checking user account login creditionals during authentication.) and also to selectively pick a requested account.

Once the user succesfully logs in. the accountLocation integer variable is used to save the array index of the account that is logged in.

When you run the program intially if no accounts exist you will be asked to create an account. Then you will have the option to Login or create an account.

once logged in you will be presented with menu only for users that are logged in. Options presented:

1. change details, 2. Make Lodgement, 3. Make Withdrawal, 4. Logout.

Change Details:

Rather then having the user enter in all their details again. I chose to ask them with details they would like to change first, then proceed to allow them to enter new details. I did it this way as to not annoy the user having to enter in everything again, and it makes it more straightforward, eaiser and quicker. when the user selects details they would like to change they will be shown the current value for that detail.

Make Lodgment / Withdrawal :

Are done with the same method "setBalance" I felt it wasnt necessary for two methods as lodgement and withdrawal preform very similar opertions, This cuts down on code and also simplifies it. I pass an interger through the setBalance method to signal whether a lodgment(1) or withdrawal(2) should take place. I do similary in the addTransaction method, with is part of the last10Transaction History feature.

Logut:

the user can logut and be presented with the main menu (login,register account). Also in the bankground when the user logs out the updated accounts (i.e if the user makes a lodgment) will be written to file.

To Run this application :

download or clone this repo and run Server.java first. which will start the server and have it listen for incoming client-socket requests. then run Client.java. You will be then asked to enter the public ip address of the computer that Server.java is running on. When I tested this locally on my laptop it was the ip address of my laptop. Whem I tested on the Amazon websever it was the public Ip address.

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Motivated by Simon & Garfunkel and others ;)