💬 Quick Chat - Chatting Application

A real-time multi-room chat application built with Spring Boot, WebSockets, SockJS, and STOMP. Multiple users can join named rooms and exchange messages instantly — no page refresh needed.

---

Features

• Real-time messaging via WebSockets (STOMP protocol)
• Multi-room support — join any room by entering a Room ID
• SockJS fallback for browsers without native WebSocket support
• Clean, responsive UI with connection status indicator
• XSS-safe message rendering
• Runs on any machine (no hardcoded IPs)

---

Tech Stack

Layer	Technology
Backend	Spring Boot 3.4.0, Spring WebSocket
Protocol	STOMP over SockJS
Frontend	Vanilla JS, SockJS client, STOMP.js
Build	Maven (Java 21)
Container	Docker (Eclipse Temurin 21 Alpine)

---

Technologies Used

Backend

• Spring Boot : Framework for creating the REST API and WebSocket server.

• WebSockets : Enables real-time, full-duplex communication between client and server.

• SockJS : Provides fallback support for browsers that do not support native WebSockets.

• STOMP (Simple Text-Oriented Messaging Protocol) : Used over WebSockets for structured message communication.

---

System Design

The application follows a real-time communication model where:

• A Spring Boot server manages WebSocket connections
• Clients communicate using the STOMP protocol
• SockJS provides fallback support for browsers without native WebSocket support

Architecture Flow

Below is the system design diagram illustrating the communication flow:

---

How to Run

Option 1 — Run the pre-built JAR (fastest)

Requires: Java 21+

java -jar target/chat-0.0.1-SNAPSHOT.jar

Open your browser at: http://localhost:3000

---

Option 2 — Build and run from source

Requires: Java 21+ and Maven 3.8+ (or use the included mvnw wrapper)

# Clone / unzip the project, then:
cd Quick-Chat

# Build
./mvnw package -DskipTests

# Run
java -jar target/chat-0.0.1-SNAPSHOT.jar

Open your browser at: http://localhost:3000

---

Option 3 — Docker

Requires: Docker

# Build the image
docker build -t quick-chat .

# Run the container
docker run -p 3000:3000 quick-chat

Open your browser at: http://localhost:3000

---

Option 4 — Change the port

To run on a different port, pass it as an argument:

java -jar target/chat-0.0.1-SNAPSHOT.jar --server.port=8080

---

Deploying to Render

Quick summary:

1. Push your code to GitHub
2. Create a new Web Service on render.com
3. Connect your repo — Render auto-detects the Dockerfile
4. Click Deploy ✅

Your app will be live at https://quickchat-f1tn.onrender.com

---

How to Use

1. Open http://localhost:3000 in two or more browser tabs/windows.
2. Type a Room ID (e.g. general, team-a) and click Join Room.
3. Enter your name and start chatting.
4. All users in the same room see each other's messages in real time.
5. Users in different rooms do not see each other's messages.

---

How It Works

1. Connection Establishment
   Clients connect to the Spring Boot server using WebSockets or SockJS as a fallback.
   The STOMP protocol is used for sending and receiving messages.

2. Messaging
   Users send messages through the WebSocket connection.
   The backend processes and broadcasts messages to the appropriate room subscribers.

3. Fallback Support
   If WebSocket support is unavailable, SockJS enables communication using HTTP-based alternatives.

---

Project Structure

src/
├── main/
│   ├── java/com/sts/
│   │   ├── ChatApplication.java          # Spring Boot entry point
│   │   ├── config/
│   │   │   └── WebSocketConfig.java      # WebSocket + STOMP broker config
│   │   ├── controller/
│   │   │   └── ChatController.java       # Handles incoming messages & broadcasts
│   │   └── model/
│   │       └── ChatMessage.java          # Message model (sender, content, recipient)
│   └── resources/
│       ├── application.properties        # Server config (port, logging)
│       └── static/
│           └── index.html                # Frontend chat UI

---

WebSocket API

Direction	Destination	Description
Client → Server	/app/{roomID}/sendMessage	Send a message to a room
Server → Client	/topic/{roomID}/messages	Subscribe to receive room messages

Message payload (JSON):

{
  "sender": "Alice",
  "content": "Hello everyone!",
  "recipient": "general"
}

---

Configuration

Edit src/main/resources/application.properties:

server.port=3000                          # Change the port
logging.level.com.sts=DEBUG              # Enable debug logs

---

📄 License

This project is open source and available under the MIT License.

---

Contributing

Contributions are welcome!

1. Fork the repository
2. Create a new branch (feature/your-feature)
3. Commit your changes
4. Push to your branch
5. Open a Pull Request

---