🚗 Car Rental System (Java, OOP) + Login Program

📌 Project Description

This project is developed as part of Object-Oriented Programming II Assignment.
It implements a Car Rental System using Java OOP principles and a Login system with masked password input.

Features

• Login System
  • Username + password authentication
  • Password masked as *
  • Max 3 login attempts
• Car Rental System
  • Add Customers
  • List available Cars
  • Rent a Car
  • Return a Car
  • Calculate rental cost by days
• OOP Concepts
  • Classes: Car, Customer, Booking, RentalAgency
  • Encapsulation (private fields, getters/setters)
  • Composition (Agency has Cars, Customers, Bookings)
  • Test cases with different scenarios

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🏗️ UML Class Diagram

Below is a simplified UML diagram for the system:

+----------------+         +----------------+
|   Customer     |         |      Car       |
+----------------+         +----------------+
| -customerId    |         | -registration  |
| -name          |         | -model         |
| -phoneNumber   |         | -year          |
+----------------+         | -available     |
| +getName()     |         | +isAvailable() |
+----------------+         +----------------+
        |                          |
        |                          |
        +-----------+--------------+
                    |
              +-----v------+
              |  Booking   |
              +------------+
              | -customer  |
              | -car       |
              | -startDate |
              | -endDate   |
              +------------+
              | +calculate |
              +------------+
                    |
             +------v-------+
             | RentalAgency |
             +--------------+
             | -cars        |
             | -customers   |
             | -bookings    |
             +--------------+
             | +rentCar()   |
             | +returnCar() |
             | +listCars()  |
             +--------------+