Caching

9. Caching

Description:

• Hibernate provides a sophisticated caching system to improve application performance.
• It includes first-level cache (session cache), second-level cache (SessionFactory cache), and query cache. - Proper caching configuration can significantly reduce database round-trips and improve application responsiveness.

First Level Cache (Session Cache)

Session session = sessionFactory.openSession();
User user1 = session.get(User.class, 1L); // Hits database
User user2 = session.get(User.class, 1L); // Returns from cache - no database hit
session.close();

Second Level Cache (SessionFactory Cache)

<!-- Enable second level cache -->
<property name="hibernate.cache.use_second_level_cache">true</property>
<property name="hibernate.cache.region.factory_class">org.hibernate.cache.ehcache.EhCacheRegionFactory</property>

@Entity
@Cacheable
@org.hibernate.annotations.Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
public class Product {
    // entity fields
}

Query Cache

<property name="hibernate.cache.use_query_cache">true</property>

Query query = session.createQuery("FROM Product WHERE category = :category");
query.setParameter("category", "electronics");
query.setCacheable(true);
List<Product> products = query.list();