Java programming

I am required to develop an automated teller machine which will be used for bank customers to perform financial transactions. The main purpose of this system is to simulate an automated teller machine with at least 10 customers for them to perform the following financial transactions: Deposit money to his/her account Withdraw money from his/her account Transfer money to another customer Check his/her account balance Besides, customers are allowed to change their ATM pin. The following characteristics are important to be included in your system: The system will ask the users to choose one of the five activities mentioned above. At the end of each activity, a receipt should be generated. All details must be saved in files – Java text files. GUIs should be done for all interactions between users and the system. This is purely for education purpose and if someone can help me code this in a very short time, that would be really great. Also I need explanation for each coding as I'm about to do presentation on it.