Chat Application

A real-time chat application built with Java, Spring Boot, WebSocket, and Redis, enabling users to create or join chat rooms and exchange messages in real-time.

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🔹 Features

• Create and join chat rooms dynamically.
• Real-time messaging using WebSocket (STOMP).
• Messages are persisted for each room.
• Pagination support for messages in each room.
• Frontend interface with live chat updates.
• Cross-origin support for local frontend (React/HTML/JS) integration.

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💻 Tech Stack

Layer	Technology
Frontend	HTML, CSS, JavaScript
Backend	Java 17, Spring Boot
Real-Time Messaging	WebSocket (STOMP)
Persistence	MongoDB (Messages), Room Repository
Authentication & Security	Spring Security (optional / role-based)
Build & Dependency	Maven
API Endpoints	REST API for Room Management
Deployment	Localhost (for development)

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🔹 API Endpoints

Endpoint	Method	Description
/api/v1/rooms	POST	Create a new room
/api/v1/rooms/{roomId}	GET	Join a room by ID
/api/v1/rooms/{roomId}/messages	GET	Get paginated messages for a room
/app/sendMessage/{roomId}	WebSocket	Send message to a room (broadcast)
/topic/room/{roomId}	WebSocket	Subscribe to messages from a room

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🔹 Project Structure

• WebSocketConfig.java → Configures WebSocket endpoints and message broker.
• ChatController.java → Handles real-time message sending and broadcasting to subscribed clients.
• RoomController.java → REST endpoints to create, join rooms and fetch paginated messages.
• Frontend JS → Handles room creation, joining, sending messages, and updating chat UI dynamically.

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🔹 How to Run

Backend

1. Clone the repository:

git clone <repo-url>

How to run project

Frontend

• Open the frontend HTML/JS in a browser.
• Enter Room ID and Username to join or create a chat room.
• Start sending messages in real-time.

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🧠 Learning Outcomes

Skill	Description
Real-Time Communication	Implemented using WebSocket and STOMP.
REST APIs	Built endpoints for room management and message retrieval.
Persistence & Pagination	Stored chat messages with pagination support.
Frontend-Backend Integration	Connected JS frontend to Spring Boot backend for live updates.
Spring Boot Practices	Learned project structure, dependency management, and configurations.

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🔹 Future Enhancements

Feature	Description
User Authentication	Add login/signup and role-based access.
Online/Offline Status	Show users' online presence in chat rooms.
File/Media Sharing	Enable sending images, files, or videos.
Private Messaging	Support one-on-one chat along with group chat.
Cloud Deployment	Deploy on cloud platforms for real-time access globally.