🚀 P2PTransfer - Peer-to-Peer File Sharing & Chat System

📌 Overview

P2PTransfer is a Java-based peer-to-peer (P2P) desktop application that enables users to:

• Discover peers on the same network
• Connect securely using session codes
• Transfer files directly between devices
• Chat in real-time (mini WhatsApp-style system)

The application is built using Java (Swing GUI) and follows a decentralized architecture — meaning no central server is required.

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✨ Features

🔍 Peer Discovery

• Automatically finds devices in the same local network
• Uses a discovery service to detect available peers

🔗 Session-Based Connection

• Connect using a unique session code
• Ensures controlled and secure communication

📁 File Transfer

• Send and receive files seamlessly
• Supports large file handling
• Queue system for multiple file transfers

💬 Real-time Chat

• Built-in messaging system
• Chat bubbles UI (WhatsApp-style)
• Bi-directional communication

🖥️ GUI Interface

• Built using Java Swing
• Clean and interactive UI
• Drag & drop file support

🔄 Bidirectional Communication

• Once connected, both peers can:

  • Send files
  • Receive files
  • Chat simultaneously

🔌 Connection Management

• Connect / Disconnect functionality
• Handles peer connection lifecycle

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🏗️ Project Structure

P2PTransfer/
│── src/
│   ├── Main.java
│   ├── AppFrame.java           # Main GUI
│   ├── PeerServer.java         # Server for incoming connections
│   ├── PeerClient.java         # Client for outgoing connections
│   ├── PeerConnection.java     # Core communication logic
│   ├── DiscoveryService.java   # Peer discovery system
│   ├── DiscoveredPeer.java     # Peer model
│   ├── Protocol.java           # Communication protocol
│   ├── SessionCode.java        # Session management
│   ├── LocalNet.java           # Network utilities
│   ├── SwingSync.java          # Thread-safe UI updates
│
│── bin/ / out/                 # Compiled files
│── .idea/                      # IDE config
│── .gitignore

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⚙️ Requirements

• Java JDK 8 or higher
• OS: Windows / Linux / macOS
• Same network connection (for peer discovery)

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▶️ How to Run

Step 1: Clone the Repository

git clone https://github.com/your-username/P2PTransfer.git
cd P2PTransfer

Step 2: Compile the Project

javac -d bin src/*.java

Step 3: Run the Application

java -cp bin Main

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📸 Demo

🖥️ Home

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🔍 UI

📁 File Transfer

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🔄 Application Workflow

1. Launch the app on two devices

2. Devices discover each other automatically

3. Select a peer or enter session code

4. Establish connection

5. Start:

   • Sending messages 💬
   • Transferring files 📁

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🔐 Security Concept

• Session-based connection prevents unauthorized access
• Direct peer-to-peer communication (no middle server)
• Structured protocol ensures safe data exchange

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🚀 Future Improvements

• ⏸ Resume interrupted transfers
• 🌐 Cross-network (internet-based) connection
• 📊 Transfer progress bar & speed tracking
• 📱 Mobile version (Android)

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✅ MIT License

• Free to use, modify, distribute
• Only requires credit

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🙌 Contribution

Contributions are welcome!

Steps:

1. Fork the repository
2. Create a new branch
3. Make changes
4. Submit a Pull Request

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👨‍💻 Author

Md. Al Imran Emon

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⭐ Final Note

This project demonstrates:

• Networking fundamentals
• Socket programming
• GUI design (Swing)
• Real-time communication systems

**Computer Networking Project. **Perfect for learning system design basics + networking + Java desktop development.

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💡 If you like this project, consider giving it a star ⭐