Java Sudoku Game

A Java-based Sudoku desktop game built using Java Swing and object-oriented programming. The project includes difficulty selection, Sudoku board loading, puzzle interaction, solver support, solution verification, and a structured Model-View-Controller style architecture.

Project Overview

This project was developed to practice Java software design, GUI development, file handling, and algorithmic problem solving through a complete Sudoku game application.

The application allows users to start a new Sudoku game, choose a difficulty level, interact with a Sudoku board, use solver functionality, and verify whether the current board solution is correct.

Features

• Java Swing desktop interface
• New game and current game options
• Difficulty selection: Easy, Medium, and Hard
• Sudoku board loading from CSV files
• Interactive Sudoku grid
• Solver functionality for missing cells
• Solution verification
• Correct and incorrect solution feedback
• Undo functionality
• Structured Model, View, and Controller packages
• Object-oriented design using multiple classes and responsibilities

Technologies Used

• Java
• Java Swing
• Object-Oriented Programming
• File handling
• CSV files
• NetBeans
• Ant build system
• Git and GitHub

Project Structure

java-sudoku-game/
│
├── src/
│   ├── Controller/        Application control flow and user interaction logic
│   ├── Model/             Sudoku game logic, board loading, validation, and checking
│   └── View/              Java Swing graphical interface
│
├── easy/                  Easy Sudoku board files
├── medium/                Medium Sudoku board files
├── hard/                  Hard Sudoku board files
│
├── screenshots/           Application screenshots
├── nbproject/             NetBeans project configuration
├── build.xml              Ant build configuration
├── manifest.mf            Manifest file
├── valid.csv              Sample valid board file
├── .gitignore
└── README.md

Main Components

Model

The Model package contains the core Sudoku logic, including:

• Board reading
• Game state management
• Row validation
• Column validation
• Box validation
• Duplicate detection
• Difficulty handling
• Board loading
• Solver and verifier logic

View

The View package contains the Java Swing screens used by the player, including:

• Start screen
• Difficulty selection screen
• Sudoku game board
• User action handling
• Validation feedback dialogs

Controller

The Controller package connects the interface with the game logic and manages the flow of the application.

Screenshots

Start Screen

Difficulty Selection

Game Board

Solver Result

Correct Validation Result

Incorrect Validation Result

How to Run the Project

Recommended Method: NetBeans

1. Install Java JDK.
2. Install Apache NetBeans.
3. Clone the repository:

git clone https://github.com/Youssufathalla/java-sudoku-game.git

4. Open NetBeans.
5. Select:

File > Open Project

6. Choose the java-sudoku-game folder.
7. Right-click the project and select:

Clean and Build

8. Click:

Run

The application should start from the main game interface.

Command Line Method

From the project directory, run:

ant clean jar

Then run:

java -jar dist/java-sudoku-game.jar

How to Use

1. Start the application.
2. Click New Game.
3. Select a difficulty level: Easy, Medium, or Hard.
4. Fill in the missing Sudoku cells.
5. Use Solver to check if a solution exists for the missing cells.
6. Use Verify to check whether the current board is solved correctly.
7. Use Undo to reverse the last move if needed.

What I Learned

• Building a complete Java desktop application
• Applying object-oriented programming to a game project
• Separating responsibilities using Model, View, and Controller-style structure
• Working with Java Swing components
• Reading and processing CSV files
• Implementing Sudoku validation logic
• Managing game state
• Handling user actions through a graphical interface
• Cleaning and publishing a Java project professionally on GitHub

Future Improvements

• Improve the graphical interface design
• Add a timer
• Add scoring system
• Add hint functionality
• Add automatic Sudoku puzzle generation
• Add unit tests
• Improve exception handling
• Add more puzzle files
• Package the application as an installer

Author

Youssuf Hatem Fathalla