Smart Cache Proxy

A Spring Boot-based cache proxy service that forwards requests to backend APIs and caches responses to improve performance.

Features

• ✅ REST API proxy with automatic caching
• ✅ In-memory caching with Spring Cache abstraction
• ✅ Cache hit/miss tracking and statistics
• ✅ Admin endpoints for cache management
• ✅ Configurable TTL (Time To Live)
• ✅ Docker support

Tech Stack

• Java 17
• Spring Boot 3.4.12
• Spring Cache (In-memory)
• Maven
• Docker

Project Structure

smart-cache-proxy/
├── src/
│   ├── main/
│   │   ├── java/com/shubh/cacheproxy/
│   │   │   ├── SmartCacheProxyApplication.java
│   │   │   ├── controller/
│   │   │   │   ├── HealthController.java
│   │   │   │   ├── ProxyController.java
│   │   │   │   └── CacheAdminController.java
│   │   │   ├── service/
│   │   │   │   ├── ProxyService.java
│   │   │   │   └── CacheStatsService.java
│   │   │   └── model/
│   │   │       └── ProxyResponse.java
│   │   └── resources/
│   │       └── application.yaml
├── Dockerfile
├── docker-compose.yml
└── pom.xml

Getting Started

Prerequisites

• Java 17 or higher
• Maven 3.6+
• Docker (optional)

Running Locally

1. Clone the repository

git clone <your-repo-url>
cd smart-cache-proxy

2. Build the project

./mvnw clean install

3. Run the application

./mvnw spring-boot:run

The application will start on http://localhost:8080

Running with Docker

1. Build the JAR file

./mvnw clean package

2. Build and run with Docker Compose

docker-compose up --build

API Endpoints

Health Check

GET /api/health

Returns the health status of the service.

GET /api/ping

Simple ping endpoint.

Proxy Endpoint

GET /proxy?path=<target-path>

Forwards the request to the backend API and caches the response.

Example:

curl "http://localhost:8080/proxy?path=/posts/1"

Response:

{
  "statusCode": 200,
  "body": "{ ... }",
  "responseTime": 703,
  "fromCache": false
}

Cache Management

Get Cache Statistics

GET /cache/stats

Response:

{
  "totalRequests": 5,
  "cacheHits": 3,
  "cacheMisses": 2,
  "hitRate": "60.00%"
}

Clear Cache

DELETE /cache/clear

Response:

{
  "message": "Cache cleared successfully"
}

Configuration

Configuration is managed in src/main/resources/application.yaml:

spring:
  application:
    name: smartCacheProxy
  cache:
    type: simple
    cache-names: api-cache

server:
  port: 8080

proxy:
  backend:
    base-url: https://jsonplaceholder.typicode.com

How It Works

1. Client sends a request to /proxy?path=/posts/1
2. ProxyController checks if the response is in cache
3. If CACHE HIT: Returns cached response (fast)
4. If CACHE MISS: Forwards request to backend API, caches the response, then returns it
5. Subsequent requests to the same path are served from cache

Key Concepts Demonstrated

• Spring Boot: REST API development
• Dependency Injection: Service layer architecture
• Spring Cache: @Cacheable annotation for caching
• Response Wrapping: Custom response model with metadata
• Statistics Tracking: Thread-safe atomic counters
• Docker: Containerization

Performance Benefits

• First Request: ~700ms (fetches from backend)
• Cached Request: <10ms (served from cache)
• Improvement: ~99% faster response time

Future Enhancements

• Redis integration for distributed caching
• Multiple cache eviction strategies (LRU, LFU)
• Cache warming on startup
• Request rate limiting
• Response compression

Author

Shubh

• Blockchain Developer
• Backend Engineer

License

This project is open source and available under the MIT License.