Real-Time Chat & Video Calling Application

An integrated, enterprise-ready Spring Boot backend providing robust services for real-time voice/video calls, secure messaging, and comprehensive administrative controls. This project consolidates four separate modules into a single, high-performance service.

🚀 Key Features

• 📽️ Video & Voice Calling: Real-time WebRTC signaling using low-level WebSockets for high-performance peer-to-peer communication.
• 💬 Real-Time Messaging: Support for both Direct (1-on-1) and Group chats using STOMP over WebSockets.
• 🔐 Advanced Authentication: Dual authentication flow with JWT-based sessions and OTP (One-Time Password) verification via email.
• 🛡️ HQ Command Dashboard (Admin):
  • Audit Logs: Comprehensive tracking of user and admin actions.
  • VPN Management: Real-time monitoring, creation, and termination of secure VPN sessions.
  • User Control: Admin approval flow for new registrations and role management.
• 📦 Unified Architecture: A clean, non-redundant codebase with shared entities and repositories for Users, Groups, and Messages.

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🛠️ Core Components & Code Snippets

1. Unified WebSocket Configuration

We use a single configuration to manage both low-level signaling (WebRTC) and high-level messaging (STOMP).

@Configuration
@EnableWebSocket
@EnableWebSocketMessageBroker
public class WebSocketConfig implements WebSocketConfigurer, WebSocketMessageBrokerConfigurer 
{

     // For Low-level WebSocket (Video Call signaling)
     @Override
     public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) 
     {
         registry.addHandler(videoCallWebSocketHandler, "/video-call").setAllowedOrigin("*");
     }

     // For STOMP WebSocket (Chat)
     @Override
     public void configureMessageBroker(MessageBrokerRegistry config) 
     {
         config.enableSimpleBroker("/topic");
         config.setApplicationDestinationPrefixes("/app");
     }
}

2. Real-Time Message Handling

The MessageController handles both RESTful direct messaging and live WebSocket broadcasts for groups.

// Handle live group messages via WebSocket
@MessageMapping("/group-chat/{groupId}")
@SendTo("/topic/group/{groupId}")
public Message handleGroupMessage(@Payload Message message, @DestinationVariable String groupId) 
{
     message.setGroupId(groupId);
     return messageService.saveMessage(message);
}

// REST endpoint for direct messaging history
@GetMapping("/chat")
public ResponseEntity<List<Message>> getChat(@RequestParam Long user1, @RequestParam Long user2) 
{
     return ResponseEntity.ok(messageService.getChat(user1, user2));
}

3. WebRTC Signaling Handler

Manages "Call Rooms" and ICE candidate exchanges between peers.

private void handleJoinCall(WebSocketSession session, String userId, String callId) 
{
     Map<String, WebSocketSession> room = callRooms.computeIfAbsent(callId, k -> new ConcurrentHashMap<>());
    
     // Announce new joiner to existing participants
     String announcement = String.format("{\"type\":\"user_joined\",\"userId\":\"%s\"}", userId);
     room.values().stream().filter(WebSocketSession::isOpen).forEach(sess -> {
        sess.sendMessage(new TextMessage(announcement));
     });
     room.put(userId, session);
}

4. Admin VPN Management

Allows HQ admins to monitor and control active secure tunnels.

@PostMapping("/terminate/{id}")
public ResponseEntity<Void> terminateSession(@PathVariable Long id) 
{
     vpnService.terminateSession(id);
     return ResponseEntity.ok().build();
}

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📂 Project Structure

backend_server/
├── src/main/java/com/backend/backend_server/
│   ├── config/             # Security, JWT, & WebSocket Configs
│   ├── controller/         # Auth, Messaging, Calling, and Admin APIs
│   ├── entity/             # JPA Entities (User, Group, Message, AuditLog, etc.)
│   ├── repository/         # Spring Data JPA Repositories
│   ├── service/            # Core business logic & signaling handlers
│   └── dto/                # Data Transfer Objects for API requests/responses
└── src/main/resources/
    └── application.properties # Database & Mail server settings

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Future Scope

Add dynamic resizeable UI for the mobile and web interfaces

Copyright

Copyright (c) 2026 Aritra Banerjee. All Rights Reserved.

This project and its source code are proprietary and confidential. Unauthorized copying of this repository or any of its files, via any medium, is strictly prohibited. No license is granted to use, modify, or distribute this code.