Distributed Chat Application

A distributed chat application built with Spring Boot using a microservice architecture.

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Features

• JWT authentication
• Backend-for-Frontend (BFF)
• Multiple microservices
• REST communication between services
• Event-driven architecture with RabbitMQ
• Bot service consuming message events

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Services

BFF

Handles external REST requests and validates JWT tokens before forwarding requests to internal services.

AuthService

Handles login and JWT generation.

UserService

Handles user data and user endpoints.

MessageService

Handles messages and publishes message-published events to RabbitMQ.

BotService

Consumes events from RabbitMQ.

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Architecture

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Technologies

• Java
• Spring Boot
• Spring Security
• RabbitMQ
• JWT
• RestClient

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Ports

Service	Port
BFF	8080
AuthService	9000
UserService	9001
MessageService	9002
BotService	9003
RabbitMQ UI	15672

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Running the project

Start RabbitMQ

docker start rabbitmq-chat

Start services

Start the following services in IntelliJ:

• AuthService
• UserService
• MessageService
• BotService
• BFF

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Demo Requests

Login

POST http://localhost:8080/api/login
Content-Type: application/json

{
  "username": "demo",
  "password": "demo"
}

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Get users

GET http://localhost:8080/api/users
Authorization: Bearer TOKEN

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Get messages

GET http://localhost:8080/api/messages
Authorization: Bearer TOKEN

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Create message

POST http://localhost:8080/api/messages
Authorization: Bearer TOKEN
Content-Type: application/json

{
  "content": "Hello from demo"
}

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Event Flow

1. Client sends request to BFF
2. BFF validates JWT
3. BFF forwards request to MessageService
4. MessageService publishes message-published
5. RabbitMQ distributes the event
6. BotService consumes the event

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Author

Edvin Karlsson