🏧 ATM Simulation System

A console-based ATM simulation built with Core Java

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📌 Description

The ATM Simulation System is a console-based Java application that replicates the core functionalities of a real-world Automated Teller Machine (ATM). Designed as a portfolio project, it showcases a solid understanding of Core Java and fundamental Object-Oriented Programming (OOP) principles including encapsulation, inheritance, polymorphism, and abstraction.

This project is ideal for beginners looking to understand how OOP concepts translate into real-world application design, and for developers who want a clean, structured Java project to reference.

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✨ Features

Feature	Description
🔐 User Authentication	Secure PIN-based login system to verify user identity
💰 Balance Inquiry	View current account balance instantly
💸 Cash Withdrawal	Withdraw funds with validation checks
🏦 Deposit Functionality	Deposit money into the account
🧾 Transaction Handling	Tracks and displays transaction history

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🛠️ Tech Stack

• Language: Java (Core Java / Java SE)
• Paradigm: Object-Oriented Programming (OOP)
• Interface: Console / Command Line Interface (CLI)
• IDE Recommended: IntelliJ IDEA / Eclipse / VS Code with Java Extension

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🧠 OOP Concepts Used

This project is a practical demonstration of the four pillars of OOP:

• Encapsulation — Account details (balance, PIN) are kept private and accessed only through controlled getter/setter methods.
• Abstraction — Complex banking logic is hidden behind simple method interfaces that the user interacts with.
• Inheritance — Common properties and behaviors are defined in base classes and extended by specific account types.
• Polymorphism — Methods behave differently based on context, enabling flexible transaction handling.

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🚀 How to Run

Follow these steps to run the project on your local machine:

Prerequisites

• Java JDK 8 or higher installed
• A terminal / command prompt

Step 1: Clone the Repository

git clone https://github.com/your-username/atm-simulation-system.git

Step 2: Navigate to the Project Directory

cd atm-simulation-system

Step 3: Compile the Java Files

javac -d bin src/*.java

Step 4: Run the Application

java -cp bin Main

💡 Tip: If using an IDE like IntelliJ IDEA or Eclipse, simply import the project and run Main.java directly.

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📁 Project Structure

atm-simulation-system/
│
├── src/
│   ├── Main.java               # Entry point of the application
│   ├── ATM.java                # Core ATM logic and menu handling
│   ├── Account.java            # Account model with balance and PIN
│   ├── Bank.java               # Bank class managing accounts
│   ├── Transaction.java        # Transaction records and history
│   └── Authentication.java     # PIN validation and login system
│
├── bin/                        # Compiled .class files (auto-generated)
│
└── README.md

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🔮 Future Improvements

Here are some enhancements planned for upcoming versions:

• 🖥️ Add a Graphical User Interface (GUI) using Java Swing or JavaFX
• 🗄️ Integrate a database (MySQL / SQLite) to persist user data
• 👥 Support for multiple user accounts
• 📋 Export transaction history to a .txt or .csv file
• 🔒 Implement account lockout after multiple failed PIN attempts
• 💱 Add currency selection and multi-currency support

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👤 Author

Your Name

Feel free to connect, contribute, or leave a ⭐ if you found this project helpful!

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Made with ☕ Java and ❤️