Price Aggregator

A Spring Boot microservice that aggregates product prices from multiple external retailers (Amazon, Walmart, Flipkart).

Parts

Part	Description	Status
Part1.md	Basic Price Fetching (Phases 1-3)	✅
Part2.md	Spring Boot Aggregator (REST API + WebClient)	✅
Part3.md	Redis Caching Layer	✅
Part4.md	Rate Limiting + Bulkheads (Resilience4j)	✅
Part5	Microservice Architecture	🚧
Part6	Event-Driven Updates (Kafka)	🚧
Part7	Highly Scalable Architecture	🚧

Quick Start

Development

./gradlew build
./gradlew bootRun

Production (Docker)

docker-compose up --build

API Endpoints

Endpoint	Description
GET /api/prices/{productId}	Fetch prices from all vendors
GET /mock-api/amazon/{productId}	Mock Amazon API
GET /mock-api/flipkart/{productId}	Mock Flipkart API
GET /mock-api/walmart/{productId}	Mock Walmart API

Tech Stack

Component	Technology
Framework	Spring Boot 4.0.5
Web	Spring MVC + WebFlux (WebClient)
Cache	Caffeine (local) + Redis (distributed)
Language	Java 25
Build	Gradle + Jib

Configuration

Profile	Description
default	Local development (no Redis)
prod	Production with Redis

See Part2.md and Part3.md for details.

Project Structure

src/main/java/in/codefarm/price/aggregator/
├── PriceAggregatorApplication.java
├── config/
│   ├── PriceConfig.java
│   ├── RedisConfig.java
│   └── WebClientConfig.java
├── controller/
│   ├── PriceController.java
│   └── MockVendorController.java
├── dto/
│   └── PriceResponse.java
├── external/
│   ├── AmazonClient.java
│   ├── FlipkartClient.java
│   ├── WalmartClient.java
│   └── PriceAggregator.java
└── service/
    ├── PriceService.java
    └── PriceCacheService.java

Docker Files

• Dockerfile - Application container
• docker-compose.yml - Redis + App orchestration