An SSH protocol-based chat room built with Spring Boot and Apache MINA SSHD, supporting anonymous users to chat in real-time via SSH connections.

• ✅ SSH Protocol Support: Users can connect directly via SSH clients
• ✅ Anonymous Chat: No registration required, start chatting immediately
• ✅ Virtual Threads: Based on JDK 21 virtual threads, supporting high-concurrency connections
• ✅ Real-time Messages: Messages broadcast to all online users in real-time
• ✅ Message History: New users can see recent chat history when joining
• ✅ User Management: Display online user list and statistics
• ✅ Command Support: Built-in chat commands

• JDK 21 - Virtual threads support
• Spring Boot 3.2.1 - Application framework
• Apache MINA SSHD 2.11.0 - SSH server implementation
• Maven - Build tool

• JDK 21 or higher
• Maven 3.6+

mvn clean compile

mvn spring-boot:run

Or build JAR and run:

mvn clean package
java -jar target/ssh-chatroom-1.0.0.jar

Use SSH client to connect to the chat room:

ssh -p 2222 localhost

Or connect to remote server:

ssh -p 2222 your-server-ip

Note:

• Supports login with any username and password (anonymous mode)
• Default port is 2222, configurable in application settings

After successful connection, you'll see the welcome interface. Supports the following operations:

• Direct text input - Send chat messages
• /help - Show help information
• /users - Show online user list
• /stats - Show chat room statistics
• /quit or /exit - Exit chat room

╔══════════════════════════════════════════════════════════════╗
║                     SSH Chat Room                           ║
║                                                              ║
║  Welcome to SSH Chat Room!                                  ║
║  - Type messages to start chatting                          ║
║  - Type '/help' for help                                    ║
║  - Type '/users' to see online users                        ║
║  - Type '/quit' to exit chat room                           ║
║                                                              ║
║  Powered by JDK21 virtual threads for high performance!     ║
╚══════════════════════════════════════════════════════════════╝

Online users: 1 | Enter message: Hello everyone!
[14:30:25] Anonymous1: Hello everyone!
Online users: 2 | Enter message: /users

Online Users (2 users):
════════════════════════════════════════
• Anonymous1 (ID: 1) - /127.0.0.1:54321
• Anonymous2 (ID: 2) - /127.0.0.1:54322
════════════════════════════════════════

Main configuration in src/main/resources/application.yml:

ssh:
  server:
    port: 2222                    # SSH server port
    host: 0.0.0.0                # Bind address
    max-connections: 100          # Maximum connections
    welcome-message: "Welcome to SSH Chat Room!"

logging:
  level:
    com.sshspring: DEBUG          # Log level

The project fully utilizes JDK 21 virtual threads:

• Each SSH connection uses an independent virtual thread
• Message broadcasting uses virtual thread pool for concurrent sending
• Supports thousands of concurrent connections without exhausting system resources

1. SshChatroomApplication - Spring Boot main application class
2. SshServerConfig - SSH server configuration
3. ChatRoomService - Chat room core service
4. SshChatShellFactory - SSH Shell factory
5. SshChatCommand - SSH command processor
6. ChatUser - User model
7. ChatMessage - Message model

src/main/java/com/sshspring/
├── SshChatroomApplication.java     # Main application class
├── config/
│   └── SshServerConfig.java       # SSH server configuration
├── model/
│   ├── ChatUser.java              # User model
│   └── ChatMessage.java           # Message model
├── service/
│   └── ChatRoomService.java       # Chat room service
└── ssh/
    ├── SshChatShellFactory.java   # SSH Shell factory
    └── SshChatCommand.java         # SSH command processor

Can easily extend the following features:

• User authentication and permission management
• Private messaging
• Chat room grouping
• Message persistence
• File transfer
• Bot integration

MIT License

Issues and Pull Requests are welcome!

For questions or suggestions, please create an Issue.