Library System with Design Patterns

This is a simple Java project demonstrating a library system that utilizes various design patterns including builder, singleton, decorator, and iterator.

Overview

The project consists of the following components:

• Book: Represents a book in the library.
• Magazine: Represents a magazine in the library.
• LibraryItem: An interface representing items in the library, implemented by both Book and Magazine classes.
• Library: Implements the singleton pattern and represents the library. It manages the collection of items (books and magazines) and supports adding items with a capacity constraint. It also implements the iterator pattern to provide a way to iterate over its items.
• LibraryBuilder: Implements the builder pattern to construct the library by adding books and magazines.
• LibraryDecorator: An abstract class for extending functionality of the Library.
• IncreaseBooksCapacityDecorator: A concrete decorator to increase the books capacity of the Library.
• DecreaseBooksCapacityDecorator: A concrete decorator to decrease the books capacity of the Library.
• App: Contains the main method to demonstrate the library system.

Design Patterns Used

• Builder Pattern: Used in the LibraryBuilder class to construct the library by adding books and magazines.
• Singleton Pattern: Implemented in the Library class to ensure only one instance of the library exists throughout the application.
• Decorator Pattern: Implemented with LibraryDecorator and its concrete decorators (IncreaseBooksCapacityDecorator and DecreaseBooksCapacityDecorator) to extend the functionality of the Library dynamically.
• Iterator Pattern: Implemented by custom iterators in the Library class to iterate over the collection of items.

Prerequisites

Before you begin, ensure you have met the following requirements:

• Maven >= 3
• Java >= 11

Usage

To run the project, first clone or download the repository to your local machine. Now, you have two options: using an IDE or using the CLI (terminal).

IDE

1. Open the project in your preferred Java IDE.
2. Run the App class.

CLI

mvn compile exec:java

The App class demonstrates the following functionalities:

• Creation of books and magazines.
• Adding items to the library.
• Displaying items in the library.
• Modifying the books capacity using decorators.
• Iterating over the library items using the Iterator pattern.

Contributors

• Lucas Catolino
• Santiago Lo Coco
• Joel Kudiyirickal