🚀 Spring Boot Caffeine Cache Demo

A lightning-fast ⚡ caching implementation demo using Spring Boot and Caffeine Cache to supercharge your application performance! 🎯

🎯 Overview

This project demonstrates a powerful caching system with a product management example, featuring:

• 💾 In-memory product storage with simulated slow service
• ☕ Caffeine cache integration with Spring Boot
• 📊 Real-time cache statistics monitoring
• 🔄 RESTful API endpoints for product operations
• ✅ 100% test coverage
• 🐚 Interactive shell script for cache behavior demonstration

🛠️ Technical Stack

• ☕ Java 21
• 🍃 Spring Boot 3.2.0
• ⚡ Caffeine Cache 3.1.8
• 🏗️ Lombok
• 🔨 Maven
• 🧪 JUnit 5 with AssertJ

⚙️ Cache Configuration

Supercharge your application with these cache settings! 🔥

Caffeine.newBuilder()
    .initialCapacity(100)    // 🌱 Initial cache size
    .maximumSize(500)        // 📈 Maximum cache entries
    .expireAfterWrite(5, TimeUnit.MINUTES)  // ⏰ Entry expiration time
    .recordStats()           // 📊 Enable statistics

🎮 API Endpoints

Method	Endpoint	Description
GET	/api/products/{id}	🔍 Retrieve a product
PUT	/api/products	📝 Update a product
DELETE	/api/products/{id}	🗑️ Delete a product
DELETE	/api/products/cache	🧹 Clear the cache
GET	/api/products/cache/stats	📊 Get cache statistics

🌟 Key Features

🏷️ Caching Annotations

Smart caching with Spring annotations:

• 📥 @Cacheable: Caches method results
• 📤 @CachePut: Updates cache entries
• 🗑️ @CacheEvict: Removes entries from cache
• ✨ @EnableCaching: Enables Spring's caching magic

📊 Cache Statistics

Monitor your cache like a pro:

• 🎯 Hit/miss counts
• 📈 Hit rate
• 🚀 Eviction count
• 📦 Cache size

⏰ Simulated Latency

Watch the caching magic happen with a simulated delay:

private void simulateSlowService() {
    Thread.sleep(3000L); // ⏳ 3-second delay
}

🧪 Testing

We take testing seriously! 🎯

• 🔬 Unit tests for all components
• 🎯 Cache behavior verification
• 🛡️ Edge case handling
• 📊 JaCoCo test coverage reporting (80%+ coverage)

🔄 Cache Testing Script

Test drive the cache with our shell script! 🚗

./test-cache.sh [iterations]

Watch it perform: 🎬

1. 📊 Initial cache stats check
2. 🆕 First product retrieval (uncached)
3. ⚡ Second product retrieval (cached)
4. 📝 Product update
5. 🧹 Cache clearing
6. 🔄 Post-clear retrieval

🚀 Building and Running

📋 Prerequisites

• ☕ Java 21 or higher
• 🔨 Maven 3.8.0 or higher

🏗️ Build

mvn clean install

🎬 Run

mvn spring-boot:run

Application launches on port 8989 🚀

💎 Code Quality

Quality is our priority! 💪

• 📝 Google Java Format enforcement
• 🔍 Maven Enforcer Plugin
• 📚 JavaDoc documentation
• 📊 JaCoCo code coverage
• ✨ Consistent formatting

🚀 Performance Benefits

Experience these amazing performance gains:

• 📉 Reduced database load
• ⚡ Lightning-fast response times
• 🔄 Smart cache eviction
• ⚙️ Flexible configuration

🌟 Best Practices

1. 🎯 Cache Configuration

   • 📦 Optimal cache sizes
   • ⏰ Smart expiration policies
   • 📊 Performance monitoring

2. 🛡️ Error Handling

   • 🔍 Exception management
   • 🧵 Thread handling
   • ✅ Null safety

3. 🧪 Testing

   • 🎯 Complete coverage
   • 🔬 Edge cases
   • 📊 Performance metrics

4. 📐 Code Organization

   • 🏗️ Clean architecture
   • 🔄 Separation of concerns
   • 💉 Dependency injection