Java RMI Chat Application

Overview

This full-stack distributed chat system implemented using Java RMI features a Swing-based graphical client and a server that communicates over a network to manage chat rooms, user authentication, and message routing while supporting group chats, private messaging, contact management, and offline message delivery.

Features

Chat Client

• User authentication (sign in and sign up)
• Send and receive private messages
• Join and leave chat rooms
• Send messages to chat rooms
• Real-time updates for messages and user status
• Graphical user interface using Swing

Chat Server

• User authentication and management
• Chat room creation, joining, and leaving
• Message routing between users and rooms
• Supports multiple concurrent users

Project Structure

Server-Side

src/
├── org/ds/
│   ├── IChatClient.java       # Client stub interface
│   ├── IChatServer.java       # Server service interface
│   ├── ChatServerImpl.java    # RMI service implementation
│   ├── User.java              # User entity class  
│   ├── Room.java              # Chat room management
│   └── Main.java              # Server bootstrap

Client-Side

src/
├── org/ds/
│   ├── IChatClient.java       # Client callback interface
│   ├── IChatServer.java       # Server interface  
│   ├── ChatClientImpl.java    # RMI client implementation
│   ├── ClientGUI.java         # Swing interface
│   └── Main.java              # Client entry point

Getting Started

Compile all Java files in both Chat-Client and Chat-Server folders.
Start the Chat-Server by running the ChatServer class.
Launch the Chat-Client by running the ClientMain class or ChatGUI class.
Make sure to have the necessary RMI security policy in place.

SecurityPolicy.policy:

grant{
    permission java.security.AllPermission;
}

Prerequisites

• Java JDK 23
• Maven
• Java RMI (included in JDK)
• Swing

License

MIT License