Welcome to the Collaborative Editor Backend — the powerful engine behind real-time document editing, syncing user edits instantly using WebSockets, Java Spring Boot, and MongoDB.

🖥️ This is the Backend (API + WebSocket) of the project. Find the frontend here: Collaborative Editor UI

🚀 Backend deployed on Render (https://collabeditor-bsua.onrender.com)

Backend:

• ☕ Java 17
• ⚙️ Spring Boot
• 🔄 Spring WebSocket (TextWebSocketHandler)
• 🧠 Jackson (for JSON parsing)
• 💾 MongoDB (document persistence)
• 🌐 Deployed via Render

• 🔄 Real-time WebSocket connections for collaborative editing
• 🔗 Join sessions with unique document URLs
• 👥 Multi-user document editing support
• 💬 Commenting system
• 🧠 Username-based session tracking
• ❌ Handles unexpected disconnects gracefully
• 🛑 Smart validation and error handling

com.thughari.collabeditor ├── websocket/ │ └── EditorWebSocketHandler.java // Handles all WebSocket communication ├── service/ │ └── WebSocketService.java // Session management, message handling ├── model/ // Document model └── CollabEditorApplication.java // Main Spring Boot application 

git clone https://github.com/thughari/CollabEditor.git cd CollabEditor

Make sure MongoDB is running locally and update the connection URI in src/main/resources/application.properties:

spring.data.mongodb.uri=mongodb://localhost:27017/collabeditor

./mvnw spring-boot:run

💡 Default port is 8080.

Connect via WebSocket to:

ws://localhost:8080/ws/editor/{documentId} 

Example with Angular:

new WebSocket('ws://localhost:8080/ws/editor/abc123');

{ "type": "join", "payload": { "documentId": "abc123", "username": "Hari" } }

{ "type": "edit", "payload": { "documentId": "abc123", "content": "Hello world!" } }

{ "type": "comment", "payload": { "documentId": "abc123", "comment": { "text": "Add a heading here", "position": 5 } } }

Sessions are automatically cleaned up when:

• WebSocket is closed
• Invalid message or document ID
• Network disconnect

1. Start MongoDB locally
2. Run backend with ./mvnw spring-boot:run
3. Launch frontend at http://localhost:4200
4. Open in multiple tabs and watch edits sync in real time!

We welcome improvements to the backend logic or performance! To contribute:

git checkout -b fix/session-bug git commit -m "Fix session handling bug" git push origin fix/session-bug

Open a Pull Request ✅

Hari Thatikonda 📫 LinkedIn | GitHub

MIT — use it freely, improve it collaboratively.