Caching

@Service
@CacheConfig(cacheNames = "nisab")  // => Default cache name
public class NisabService {

    @Cacheable  // => Caches return value, key = method parameters
    public BigDecimal getCurrentNisab() {
        // => Expensive calculation or database query
        // => Only executed if not in cache
        return calculateFromGoldPrice();  // => Called once, then cached
    }

    @Cacheable(key = "#currency")  // => Custom cache key
    public BigDecimal getNisabForCurrency(String currency) {
        return convertNisab(getCurrentNisab(), currency);
    }

    @CacheEvict(allEntries = true)  // => Clears cache
    public void updateNisab(BigDecimal newValue) {
        // => Update database, then clear cache
        nisabRepository.save(newValue);
    }

    @CachePut(key = "#currency")  // => Always execute, update cache
    public BigDecimal refreshNisab(String currency) {
        return fetchLatestFromSource(currency);
    }
}

spring:
  cache:
    type: caffeine # => Local in-memory cache
    caffeine:
      spec: maximumSize=1000,expireAfterWrite=10m
      # => 1000 entries, 10 minute TTL

spring:
  cache:
    type: redis
  redis:
    host: redis.internal
    port: 6379
  cache:
    redis:
      time-to-live: 600000  # => 10 minutes in milliseconds