🎵 Jukebox - Music Playlist Management System

📋 Project Overview

Jukebox is a sophisticated music playlist management system built using object-oriented design principles in Java. The application allows users to create, manage, and play custom playlists with an intuitive command-based interface. This project demonstrates clean architecture, command pattern implementation, and robust exception handling.

✨ Features

• User Management: Create and manage multiple user profiles
• Playlist Operations: Create, modify, delete, and play playlists
• Song Management: Load songs from CSV, search and play individual tracks
• Command Pattern: Extensible command-based architecture for easy feature addition
• Data Persistence: Load song data from CSV files
• Exception Handling: Comprehensive custom exceptions for better error management

🏗️ Architecture

The project follows a layered architecture with clear separation of concerns:

Core Packages

com.crio.jukebox/
├── appConfig/          # Application configuration
│   └── AppConfig.java
├── commands/           # Command pattern implementations
│   ├── ICommand.java
│   ├── CommandInvoker.java
│   ├── CreateUserCommand.java
│   ├── CreatePlayListCommand.java
│   ├── ModifyPlayListCommand.java
│   ├── DeletePlayListCommand.java
│   ├── PlayPlayListCommand.java
│   ├── PlaySongCommand.java
│   └── LoadDataCommand.java
├── entities/           # Domain models
│   ├── BaseEntity.java
│   ├── User.java
│   ├── Song.java
│   ├── PlayList.java
│   └── PlayListStatus.java
├── repositories/       # Data access layer
│   ├── CRUDRepository.java
│   ├── UserRepository.java
│   ├── SongRepository.java
│   └── PlayListRepository.java
├── services/          # Business logic layer
│   ├── UserService.java
│   ├── SongService.java
│   └── PlayListService.java
└── exceptions/        # Custom exceptions
    ├── UserNotFoundException.java
    ├── SongNotFoundException.java
    ├── PlayListNotFoundException.java
    ├── PlayListIsEmptyException.java
    ├── ActivePlayListNotFoundException.java
    ├── SongNotFoundInPlayListException.java
    ├── CommandNotFoundException.java
    ├── InvalidCommandException.java
    └── CSVFileLoadingException.java

🎯 Key Components

Commands

Implements the Command Design Pattern for extensible functionality:

• CreateUserCommand - Creates new user profiles
• CreatePlayListCommand - Creates custom playlists
• ModifyPlayListCommand - Add/remove songs from playlists
• DeletePlayListCommand - Remove playlists
• PlayPlayListCommand - Play songs from a playlist
• PlaySongCommand - Play individual songs
• LoadDataCommand - Load song data from CSV files

Entities

Core domain models representing the system's data:

• User - User profile information
• Song - Song metadata (name, genre, album, artist)
• PlayList - Collection of songs belonging to a user
• PlayListStatus - Enumeration for playlist states

Services

Business logic layer implementing core functionality:

• UserService - User management operations
• SongService - Song catalog management
• PlayListService - Playlist operations and playback

Repositories

Data access layer with CRUD operations:

• Generic CRUDRepository interface
• Concrete implementations for Users, Songs, and Playlists

🚀 Getting Started

Prerequisites

• Java 8 or higher
• Gradle 6.x or higher

Installation

1. Clone the repository

   git clone <repository-url>
   cd jukebox

2. Build the project

   ./gradlew build

3. Run the application

   ./gradlew run

   Or run directly:

   java -jar build/libs/jukebox.jar

📖 Usage

The application supports the following commands:

Load Data

LOAD-DATA <csv-file-path>

Load songs from a CSV file into the system.

Create User

CREATE-USER <user-name>

Create a new user profile.

Create Playlist

CREATE-PLAYLIST <user-id> <playlist-name> <song-id-1> <song-id-2> ...

Create a new playlist for a user with specified songs.

Modify Playlist

MODIFY-PLAYLIST <playlist-id> <ADD/DELETE> <song-id>

Add or remove songs from an existing playlist.

Delete Playlist

DELETE-PLAYLIST <user-id> <playlist-id>

Delete a user's playlist.

Play Playlist

PLAY-PLAYLIST <user-id> <playlist-id>

Play songs from a specific playlist.

Play Song

PLAY-SONG <user-id> <song-id>

Play a specific song.

📊 Sample Data Format

Songs CSV format:

id,name,genre,album,artist
1,Song Name,Pop,Album Name,Artist Name

🧪 Testing

Run the test suite:

./gradlew test

Run with coverage:

./gradlew test jacocoTestReport

🔧 Configuration

The application can be configured through the AppConfig.java file:

• Default data file paths
• Repository implementations
• Service configurations

🤝 Contributing

Contributions are welcome! Please follow these steps:

1. Fork the repository
2. Create a feature branch (git checkout -b feature/AmazingFeature)
3. Commit your changes (git commit -m 'Add some AmazingFeature')
4. Push to the branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

📝 Design Patterns Used

• Command Pattern: Encapsulates commands as objects for flexible execution
• Repository Pattern: Abstracts data access logic
• Service Layer Pattern: Separates business logic from presentation
• Singleton Pattern: Used in repository and service management

🎓 Learning Outcomes

This project demonstrates:

• Clean code principles and SOLID design
• Object-oriented programming best practices
• Design pattern implementation
• Layered architecture design
• Exception handling strategies
• CSV data processing
• Command-line interface design

📄 License

This project is part of Crio.Do's learning platform.

👥 Authors

Developed as part of the Object Modeling module at Crio.Do

🙏 Acknowledgments

• Crio.Do for the project framework
• Java community for best practices guidance

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Built with ❤️ using Java and Gradle

Last Updated: October 2025