SpringBoot-RabbitMQ-Order-System

A practical implementation of asynchronous communication using Spring Boot and RabbitMQ. The system processes orders without blocking the client request using event-driven architecture.

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📌 Overview

This project demonstrates a basic event-driven flow using Spring Boot and RabbitMQ.

• Customers can create orders using a REST API.
• Orders are immediately sent to RabbitMQ as messages (events).
• A consumer reads the messages asynchronously and processes them.
• Client receives an immediate response without waiting for processing.

This demo shows the core idea of asynchronous communication and event-driven architecture before scaling to multiple microservices like Payment or Notification services.

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🏗 Flow

Client ---> Order Service ---> returns "Order Received" immediately | | publishes OrderPlaced event v Consumer (simulating Payment & Notification) processes order asynchronously

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🛠 Tech Stack

• Java 21
• Spring Boot
• RabbitMQ
• Maven
• REST API

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🐰 Installing RabbitMQ For Windows (Step-by-Step Guide)

RabbitMQ requires Erlang to be installed first.

1️⃣ Install Erlang

1. Go to the official Erlang website: https://www.erlang.org/downloads
2. Download the latest Windows installer.
3. Install it normally.
4. Set environment variable:
   • Variable Name: ERLANG_HOME
   • Value:

     C:\Program Files\Erlang OTP\erl-XX.X

5. Open CMD and verify:

   erl

   If Erlang shell opens successfully → Installation is correct.

2️⃣ Install RabbitMQ

1. Go to official RabbitMQ website: https://www.rabbitmq.com/docs/download

2. Download the Windows installer.

3. Install normally.

4. Add RabbitMQ sbin folder to PATH:

   Example:

   C:\Program Files\RabbitMQ Server\rabbitmq_server-3.xx.x\sbin

3️⃣ Enable Management Plugin

1. Open CMD as Administrator:

   rabbitmq-plugins enable rabbitmq_management

2. Restart the service:

   net stop RabbitMQ
   net start RabbitMQ

4️⃣ Access RabbitMQ Dashboard

1. Open your browser:

   http://localhost:15672

2. Default credentials:

    username: guest
    password: guest

   If the dashboard appears successfully → RabbitMQ is ready 🎉

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🚀 Running the Demo

1. Start RabbitMQ
2. Run your Spring Boot application
3. Test endpoint:

   POST /orders
   Content-Type: application/json
    
   {
      "productName": "Book",
      "productPrice": "20",
      "productQuantity": "2"
   }

   • Response:

     {
        "order": {
           "productName": "Book",
           "productPrice": "20",
           "productQuantity": "2"
        },
        "orderStatus": "Placed",
        "message": "Your order has been placed successfully"
     }

   • Consumer prints the message asynchronously:

     Consumer received OrderResponseDTO{...}

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🔥 What This Demo Shows

• Asynchronous message publishing using RabbitMQ
• Event-driven concept
• Immediate response to client
• How consumers process messages independently