README - Caffeine — ContextQMD

Hibernate can be configured to use a second-level cache to reduce the number of accesses to the database by caching data in memory to be shared between sessions.

In hibernate.properties specify the JCache provider and enable the second-level cache.

ini

hibernate.cache.use_second_level_cache=true
hibernate.cache.region.factory_class=jcache
hibernate.javax.cache.provider=com.github.benmanes.caffeine.jcache.spi.CaffeineCachingProvider

The caches are configured in Caffeine's application.conf following the reference format. The default file path may be overridden by setting the hibernate.javax.cache.uri in the previous step.

hocon

caffeine.jcache {
  default {
    monitoring.statistics = true
  }

  # Hibernate framework caches
  default-query-results-region {}
  default-update-timestamps-region {}

  # Hibernate application caches
  com.github.benmanes.caffeine.examples.hibernate.User {}
}

Enable caching on the entity.

java

@Entity
@Cache(usage = READ_WRITE)
public class User { ... }

Hibernate will then manage the cache to transparently avoid database calls.

java

// miss on first access
sessionFactory.fromSession(session -> session.get(User.class, id));
assertThat(sessionFactory.getStatistics().getSecondLevelCacheMissCount()).isEqualTo(1);

// hit on lookup
sessionFactory.fromSession(session -> session.get(User.class, id));
assertThat(sessionFactory.getStatistics().getSecondLevelCacheHitCount()).isEqualTo(1);