Real-Time Chat Application

A modern, production-ready real-time chat and file-sharing backend built with Java 21, Spring Boot 3.x, GraphQL, WebSockets, REST, and AWS S3.

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Features

• User Management

  • Registration, email verification, password reset, profile, avatar upload
  • User roles/permissions (USER, ADMIN)
  • User preferences (notification settings, file visibility, etc.)

• Authentication & Security

  • JWT authentication (REST, GraphQL, WebSocket)
  • CORS, HTTPS, rate limiting, audit logging
  • Password hashing (BCrypt), email verification

• Real-Time Messaging

  • WebSocket and GraphQL Subscriptions
  • Message types: text, image, file
  • Input validation, filtering, pagination, search

• File Management

  • Upload to S3, virus scanning (ClamAV), quotas, sharing, access control
  • File deletion, listing, signed URLs, per-user folders
  • Avatar upload and validation

• Notifications

  • Persistent, email, and WebSocket notifications
  • Pagination, search, mark as read, delete, bulk actions

• Admin Dashboard

  • User, file, quota, and system health monitoring
  • Audit log display (search, pagination)
  • Role management, user profile editing

• Monitoring & Observability

  • Actuator endpoints (health, liveness, readiness, Prometheus metrics)
  • Centralized logging (ELK/EFK/cloud)
  • Dockerized, Flyway migrations, production profiles

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System Design Diagram

flowchart TD
  User["Web/Frontend"]
  Backend["Spring Boot App"]
  REST["REST API (Swagger)"]
  GraphQL["GraphQL API (Playground)"]
  WS["WebSocket"]
  Admin["Admin Dashboard"]
  Actuator["Actuator/Prometheus"]
  Audit["Audit Log Service"]
  Notif["Notification Service"]
  UserSvc["User Service"]
  FileSvc["File Service"]
  DB["PostgreSQL"]
  Cache["Redis"]
  S3["S3"]
  ClamAV["ClamAV"]
  SMTP["SMTP"]
  Prom["Prometheus/Grafana"]
  Logs["ELK/EFK"]

  User-->|REST/GraphQL|REST
  User-->|GraphQL|GraphQL
  User-->|WebSocket|WS
  User-->|Admin|Admin
  REST-->|Service|UserSvc
  GraphQL-->|Service|UserSvc
  WS-->|Notifications|Notif
  Admin-->|Audit|Audit
  UserSvc-->|DB|DB
  UserSvc-->|Cache|Cache
  FileSvc-->|S3|S3
  FileSvc-->|VirusScan|ClamAV
  Notif-->|Email|SMTP
  Actuator-->|Metrics|Prom
  Backend-->|Logs|Logs
  Audit-->|Logs|Logs
  FileSvc-->|Audit|Audit
  UserSvc-->|Audit|Audit
  Notif-->|Audit|Audit
  Admin-->|Health|Actuator
  Actuator-->|Health|Prom

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API Documentation

• REST API (Swagger UI): http://localhost:8080/swagger-ui.html
• GraphQL Playground: http://localhost:8080/graphiql

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Code Samples

REST: Register User

curl -X POST "http://localhost:8080/api/user/register" -d "username=alice&email=alice@example.com&password=secret"

REST: Login

curl -X POST "http://localhost:8080/api/user/login" -d "username=alice&password=secret"

GraphQL: Send Message

mutation {
  message(body: "Hello!", to: "bob", type: "text", token: "Bearer <JWT>") {
    items { from to body sentAt messageType }
  }
}

GraphQL: Subscribe to Inbox

subscription {
  inbox(to: "bob", token: "Bearer <JWT>") {
    items { from to body sentAt messageType }
  }
}

File Upload (Avatar)

curl -X POST "http://localhost:8080/api/user/upload-avatar" -F "username=alice" -F "file=@avatar.png"

Postman Collection

• Export from Swagger UI or see postman_collection.json (to be included).

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Setup & Environment

1. Clone the repo:

   git clone <repo-url>
   cd realtime-chat

2. Configure environment variables:
   • See src/main/resources/application.properties for required secrets (JWT, DB, AWS, email, etc.)
   • Use .env or your orchestrator's secret manager for production
3. Run with Docker Compose:

   docker-compose up --build

   • Services: app, PostgreSQL, Redis, ClamAV, (optionally NGINX for HTTPS)
4. Database migrations:
   • Flyway runs automatically on startup

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Deployment

• Production:
  • Set SPRING_PROFILES_ACTIVE=prod
  • Use a real SMTP server, S3 bucket, and secure secrets
  • Use a reverse proxy (NGINX, ALB) for HTTPS
  • Configure Prometheus/Grafana for monitoring
  • Forward logs to ELK/EFK/cloud logging

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Troubleshooting

• Health checks:
  • http://localhost:8081/actuator/health
  • http://localhost:8081/actuator/prometheus
• Common issues:
  • Check Docker logs for errors
  • Ensure all secrets are set via environment variables
  • Check S3, SMTP, and DB connectivity

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Contributing

• PRs welcome! Please add tests and update documentation.

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For more details, see the code, Swagger UI, and GraphQL Playground.