Java Multi-threaded Chat Server

A robust, multi-threaded chat server implementation in Java that allows multiple clients to connect and communicate in real-time. The server supports both broadcast and private messaging capabilities, with a thread pool architecture for efficient client handling.

Features

• Multi-client support using thread pool architecture
• Real-time message broadcasting
• Private messaging between users
• User management (username changes, listing connected users)
• Command-based interface
• Graceful shutdown handling

Technical Architecture

The application consists of three main components:

1. Main: Entry point of the application that initializes and starts the server
2. Server: Manages incoming connections and maintains the thread pool
3. ServerWorker: Handles individual client connections and message processing

Server Configuration

• Default Port: 8080
• Thread Pool Size: 10 concurrent connections
• Connection handling: Non-blocking using Java NIO

Available Commands

Users can interact with the server using the following commands:

• /w <username> <message> - Send a private message to a specific user
• /h - Display help menu with available commands
• /c - Change username
• /l - List all connected users
• /q - Quit the chat server

Getting Started

Prerequisites

• Java Development Kit (JDK) 8 or higher
• Java IDE (recommended: IntelliJ IDEA or Eclipse)

Running the Server

1. Compile the Java files:

javac io/codeforall/fanstatics/*.java

2. Run the server:

java io.codeforall.fanstatics.Main

The server will start and listen for connections on port 8080.

Connecting to the Server

Clients can connect to the server using any TCP client (such as Telnet or a custom client application):

telnet localhost 8080

Implementation Details

Thread Safety

The server implements several thread-safety measures:

• Synchronized access to the shared client list
• Thread pool management for controlled resource usage
• Proper connection cleanup on client disconnect

Error Handling

The implementation includes:

• Graceful shutdown procedures
• Connection error handling
• Runtime exception management
• Resource cleanup in case of failures

Contributing

Feel free to submit issues and enhancement requests!

Future Enhancements

Potential improvements that could be added:

1. SSL/TLS support for secure communications
2. Persistent chat history
3. User authentication
4. Custom room creation
5. File sharing capabilities