ATM Console Application

📌 Project Overview

This project is a Core Java console-based ATM simulation designed to demonstrate object-oriented programming (OOP) concepts and backend logic.
It simulates basic ATM functionalities such as PIN validation, balance inquiry, deposit, withdrawal, and mini statement generation.

The project focuses on clarity of logic, clean design, and strong Java fundamentals, making it suitable as an academic mini-project and for technical interview discussions.

---

🛠️ Technologies Used

• Java (Core Java)
• Object-Oriented Programming (OOP)
• Console-based input/output

---

📂 Project Structure

ATMProject/

│

├── Account.java // Abstraction + Encapsulation

├── SavingsAccount.java // Inheritance + Polymorphism

├── ATMService.java // ATM business logic

└── Main.java // Program execution and user interaction

---

🧠 OOP Concepts Implemented

Concept	Description
Encapsulation	Private PIN and balance with controlled access
Abstraction	Abstract Account class
Inheritance	SavingsAccount extends Account
Polymorphism	Overridden withdraw() method

---

⚙️ Features

• PIN authentication with limited attempts
• Balance inquiry
• Deposit with validation
• Withdrawal with insufficient balance handling
• Mini statement (stores last 5 transactions)
• Exception handling for invalid user input
• Menu-driven console interface

---

▶️ How to Run the Project

1. Clone the repository:

   git clone https://github.com/your-username/ATMProject.git
   

2. Open the project in any Java IDE (Eclipse / IntelliJ / VS Code).

3. Compile and run Main.java.

4. Enter the PIN when prompted.

5. Default PIN: 1234 and Initial Balance: 10000 (later values hardcoded can be changed in code if required)

---

🚫 Limitations

• Supports only a single user account

• Console-based application (no GUI or web interface)

• No database or persistent storage

• Basic security (PIN is not encrypted)

---

🔮 Future Enhancements

• Support for multiple user accounts

• Database integration for persistent storage

• PIN hashing for improved security

• Web or GUI-based frontend

• Concurrent user handling

---

🎯 Learning Outcomes

Practical understanding of Core Java fundamentals

Implementation of all major OOP concepts

Input validation and exception handling

Writing clean, modular, and interview-ready code