Bank System Simulator

This is a comprehensive, console-based banking application built in Java. It simulates the core functionalities of a banking system, including secure user/admin roles, financial transactions, and database logging.

This project connects to a MySQL database using JDBC and is built on a professional 3-Tier (Layered) Architecture to ensure clean, manageable, and scalable code.

Key Features

• 3-Tier Architecture: Code is strictly separated into Presentation (UI), Business Logic (Services), and Data Access (DAO) layers.
• Dual User Roles:
  • Customer Role: Can create an account, log in, deposit, withdraw, transfer, and view their transaction history.
  • Admin Role: Can log in, view all user accounts, search for users, view system-wide statistics, and manage user accounts (freeze/unfreeze, delete, update).
• Security:
  • Password Hashing: All user and admin passwords are hashed using SHA-256.
  • Input Validation: User inputs for emails, phone numbers, and password strength are validated.
  • Account Freezing: Admin can freeze and unfreeze user accounts.
• Database & Transactions:
  • MySQL & JDBC: All account and transaction data is stored in a MySQL database.
  • Transaction Logging: Every deposit, withdrawal, and transfer is recorded in a separate transactions table to generate a mini-statement.

Technology Stack

• Language: Java (JDK 17+)
• Database: MySQL
• Connectivity: JDBC (via MySQL Connector/J)
• IDE: IntelliJ IDEA

How to Run This Project

1. Database Setup

1. Open MySQL Workbench (or any MySQL client).

2. Create a new database schema: sql CREATE DATABASE banking_simulator;

3. You do not need to create the tables. The Java application will do this automatically on its first run (in the initializeDatabase method).

2. Configure the Project

1. Open the project in IntelliJ IDEA.

2. Navigate to org.example.BankSystemIntegrated.java.

3. Find this line (around line 19): java private static final String DB_PASS = "openssl rand -base64 18";

4. This is the most important step: Change "openssl rand -base64 18" to your actual MySQL password.

   • Example: private static final String DB_PASS = "MyRootPassword123!";

3. Add the JDBC Driver

1. Download the MySQL Connector/J .jar file from the official MySQL website. (Select "Platform Independent" and get the ZIP archive).
2. Unzip the file and find the .jar file.
3. In IntelliJ, go to File $\rightarrow$ Project Structure...
4. Select Libraries from the side menu.
5. Click the + (plus) icon $\rightarrow$ Java.
6. Find and select the mysql-connector-j-x.x.x.jar file you downloaded.
7. Click OK on both windows.

4. Run the Application

1. Open the BankSystemIntegrated.java file.
2. Right-click in the file and select "Run 'BankSystemIntegrated.main()'".
3. The application will start in your console, connect to the database, create the tables, and show the main menu.

Default Admin Login

The system automatically creates a default admin user for you.

• Username: admin
• Password: admin