Vehicle Rental Management System

A Java-based vehicle rental management system developed as a university course project. This application simulates the operations of a vehicle rental agency, including vehicle reservations, rental transactions, pricing based on time periods, and role-based user interfaces for employees and managers.

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Technologies

• Java (Object-Oriented Programming)
• Linked Lists
• Java Swing (GUI Development)
• Java Collections Framework
  • ArrayList
  • HashMap
• Exception Handling
  • Custom checked exceptions
• Date & Time / Time-Based Logic

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Features

Vehicle Class Hierarchy

• A base Vehicle class defines shared vehicle attributes and behaviors.
• Subclasses (Car, SUV, Minivan) extend the base class with specialized behavior.

Reservation and Rental System

• Vehicles can be reserved and rented for specific time periods.
• Reservation details and rental details are tracked separately.

Transaction Management

• All rentals are recorded as transactions.
• Transactions are stored, retrieved, and managed through a centralized system.

Pricing and Rate Calculation

• Rental prices are determined using current vehicle rates.
• Time periods affect pricing through configurable rate logic.

Role-Based User Interfaces

• An employee GUI for handling rentals and reservations.
• A manager GUI for administrative and management tasks.

Exception-Driven Validation

• Custom exceptions ensure invalid operations are prevented, including:
  • Reserving unavailable vehicles
  • Accessing vehicles that do not exist
  • Renting unreserved vehicles

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The Process

• Since this was a university project, a UML diagram was provided and used to guide development, along with two files containing starter code. All remaining files were created from scratch.

• A base abstract Vehicle class was created, including constructors, getters, and setter methods. This class was then extended by Car, SUV, and Minivan subclasses to represent different vehicle types, each with their own constructors and toString methods.

• Next, the Transaction and Transactions classes were implemented using a linked list model, with each class containing constructors, getters, and setters for managing nodes and traversal.

• The Reservation class was then implemented to track vehicle status and store all necessary information for reserved vehicles.

• Custom exceptions were added to enforce business rules and prevent invalid system states, such as:

  • Invalid VIN numbers
  • Reserving an already reserved vehicle
  • Unreserving a vehicle that is not currently reserved

• Finally, Swing-based GUIs were implemented to provide separate interfaces for employees and managers, each supporting their own set of operations.

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What I Learned

• Designing large object-oriented systems with many interacting classes
• Applying inheritance and polymorphism in real-world simulations
• Separating GUI logic from backend logic
• Managing application state across multiple components

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Author

Diego Ramos
COSC 237 -- Fall 2025