🏦 Online Banking System (Java + MySQL + Maven)

A simple Command Line Interface (CLI) banking system built using Java JDBC + MySQL, managed with Maven.
This project supports customer management, account management, authentication, and transactions.

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⚙️ Project Highlights

• Maven: Handles dependencies like MySQL Connector and BCrypt automatically.
• Java JDBC: Connects to MySQL/MariaDB database.
• CLI-based: Easy to run and test from terminal.

🚀 Features

👤 Customer

• Create new customer with unique cid.
• Store customer details: name, email, address, contact, password (hashed with BCrypt).
• Prevent duplicate customers (same name + email → reuse existing cid).
• Update customer details.
• Delete customer (with all accounts, via ON DELETE CASCADE).

💳 Account

• Multiple accounts per customer.
• Each account has a unique account number (2025XXXX format).
• Store account balance.
• Deposit, withdraw, transfer money between accounts.

🔒 Security

• Passwords hashed with BCrypt (12 rounds).
• Authentication using email + password.

📊 Transactions

• Deposit money.
• Withdraw money (with balance check).
• Transfer between accounts.

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📂 Project Structure

online-banking-system/ 
├── src/
│   ├── online/banking/databaseConnection/
│   │   └── DatabaseConnection.java       # Handles MySQL DB connection
│   │
│   ├── online/banking/dao/
│   │   ├── CustomerDao.java              # Interface for customer operations
│   │   ├── AccountDao.java               # Interface for account operations
│   │   ├── impl/
│   │   │   ├── CustomerDaoImpl.java      # Implementation of customer logic
│   │   │   └── AccountDaoImpl.java       # Implementation of account logic
│   │
│   ├── online/banking/model/
│   │   ├── Customer.java                 # Customer entity
│   │   └── Account.java                  # Account entity
│   │
│   ├── online/banking/service/
│   │   └── BankingService.java           # Service layer combining DAOs
│   │
│   ├── online/banking/util/
│   │   └── PasswordUtils.java            # BCrypt hashing + verification
│   │
│   └── Main.java                         # Entry point (CLI menu)
│
├── lib/
│   ├── mysql-connector-j-8.0.33.jar      # MySQL JDBC driver
│   └── jbcrypt-0.4.jar                   # BCrypt library
│
└── README.md

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🗂️ Database Schema

Table: customer

CREATE TABLE customer (
    cid INT AUTO_INCREMENT PRIMARY KEY,
    customerName VARCHAR(100) NOT NULL,
    customerEmail VARCHAR(100) NOT NULL UNIQUE,
    customerAddress VARCHAR(200),
    customerContact VARCHAR(20),
    customerPassword VARCHAR(255) NOT NULL
);

Table: account

CREATE TABLE account (
    accountNo BIGINT PRIMARY KEY,
    balance INT NOT NULL,
    cid INT,
    FOREIGN KEY (cid) REFERENCES customer(cid)
    ON DELETE CASCADE
    ON UPDATE CASCADE
);

🛠️ Setup Instructions

1️⃣ Clone the Project

git clone https://github.com/your-username/online-banking-system.git
cd online-banking-system

2️⃣ Database Setup

CREATE DATABASE bankingsystem;
USE bankingsystem;

-- Run the table creation scripts from the Database Schema section

3️⃣ Configure Database Connection

Edit DatabaseConnection.java:

String url = "jdbc:mysql://localhost:3306/DB_NAME"; // replace DB_NAME with your database name
String user = "root";       // use as your choice
String pass = "yourpassword";

4️⃣ Run the Project

javac -cp .:lib/mysql-connector-j-8.0.33.jar:lib/jbcrypt-0.4.jar src/Main.java
java -cp .:lib/mysql-connector-j-8.0.33.jar:lib/jbcrypt-0.4.jar src/Main

CLI Menu Example

=== Online Banking System ===
1. Create New Customer + Account
2. Add Account to Existing Customer
3. Login (Email + Password)
4. Deposit Money
5. Withdraw Money
6. Transfer Money
7. View Account Details
8. Update Customer Info
9. Delete Customer
0. Exit
Enter your choice:

📝 Example Usage

➕ Add Customer + Account

addCustomerOrAccount("Alice", "alice@mail.com", "Dhaka", "017...", "pass123", 2000);
// Output: Customer Account has been created successfully with Account No: 20251234

➕ Add Another Account for Same Customer

addCustomerOrAccount("Alice", "alice@mail.com", "Pabna", "018...", "new123", 5000);
// Output: New account created for existing customer (cid=1) → Account No: 20254321

❌ Delete Customer

DELETE FROM customer WHERE cid = 1;
-- This will also delete all linked accounts automatically

📚 Technologies Used

• Java 21
• MySQL
• JDBC
• BCrypt (for password hashing)
• Maven (for dependency management)

Dependencies in pom.xml

-  MySQL Connector/J    <!--- https://mvnrepository.com/artifact/com.mysql/mysql-connector-j/8.3.0 -->
-  BCrypt for password hashing    <!--- https://mvnrepository.com/artifact/at.favre.lib/bcrypt/0.10.2 -->

💻 Linux Setup: MariaDB + Apache + PHPMyAdmin

If you are on Linux and using MariaDB, here’s how to set up and start your database, Apache, and access PHPMyAdmin in the browser.

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1️⃣ Start MariaDB Server

sudo systemctl start mariadb
sudo systemctl enable mariadb

2️⃣ Install and Start Apache + PHP

sudo apt update
sudo apt install apache2 php libapache2-mod-php php-mysql -y
sudo systemctl start apache2
sudo systemctl enable apache2

3️⃣ Install PHPMyAdmin

sudo apt install phpmyadmin -y

During installation, select apache2 and configure the database for phpmyadmin with dbconfig

4️⃣ Access PHPMyAdmin

Open your web browser and go to:

http://localhost/phpmyadmin

Login with your MariaDB credentials.