Package org.hibernate.cache

This package defines APIs/SPIs and implementations for the Hibernate second-level cache.

See:
Description

Interface Summary

Cache	Deprecated. As of 3.3; see for details.
CacheConcurrencyStrategy	Deprecated. As of 3.3; see for details.
CacheDataDescription	Describes attributes regarding the type of data to be cached.
CacheProvider	Deprecated. As of 3.3; see for details.
CollectionRegion	Defines the contract for a cache region which will specifically be used to store collection data.
EntityRegion	Defines the contract for a cache region which will specifically be used to store entity data.
GeneralDataRegion	Contract for general-purpose cache regions.
OptimisticCache	A contract for transactional cache implementations which support optimistic locking of items within the cache.
OptimisticCacheSource	Contract for sources of optimistically lockable data sent to the second level cache.
QueryCache	Defines the contract for caches capable of storing query results.
QueryCacheFactory	Defines a factory for query cache instances.
QueryResultsRegion	Defines the contract for a cache region which will specifically be used to store query results.
ReadWriteCache.Lockable
Region	Defines a contract for accessing a particular named region within the underlying cache implementation.
RegionFactory	Contract for building second level cache regions.
TimestampsRegion	Defines the contract for a cache region which will specifically be used to store entity "update timestamps".
TransactionalDataRegion	Defines contract for regions which hold transactionally-managed data.
TransactionAwareCache	Marker interface for identifying cache impls which are aware of JTA transactions

Class Summary

AbstractJndiBoundCacheProvider	Support for CacheProvider implementations which are backed by caches bound into JNDI namespace.
CacheKey	Allows multiple entity classes / collection roles to be stored in the same cache region.
EhCache	EHCache plugin for Hibernate EHCache uses a net.sf.ehcache.store.MemoryStore and a net.sf.ehcache.store.DiskStore.
EhCacheProvider	Cache Provider plugin for ehcache-1.2.
FilterKey	Allows cached queries to be keyed by enabled filters.
HashtableCache	A lightweight implementation of the Cache interface
HashtableCacheProvider	A simple in-memory Hashtable-based cache impl.
NoCacheProvider	Implementation of NoCacheProvider.
NonstrictReadWriteCache	Caches data that is sometimes updated without ever locking the cache.
OSCache
OSCacheProvider	Support for OpenSymphony OSCache.
QueryKey	A key that identifies a particular query with bound parameter values.
ReadOnlyCache	Caches data that is never updated.
ReadWriteCache	Caches data that is sometimes updated while maintaining the semantics of "read committed" isolation level.
ReadWriteCache.Item	An item of cached data, timestamped with the time it was cached,.
ReadWriteCache.Lock	A soft lock which supports concurrent locking, timestamped with the time it was released
SingletonEhCacheProvider	Singleton cache Provider plugin for Hibernate 3.2 and ehcache-1.2.
StandardQueryCache	The standard implementation of the Hibernate QueryCache interface.
StandardQueryCacheFactory	Standard Hibernate implementation of the QueryCacheFactory interface.
SwarmCache
SwarmCacheProvider	Support for SwarmCache replicated cache.
Timestamper	Generates increasing identifiers (in a single VM only).
TransactionalCache	Support for fully transactional cache implementations like JBoss TreeCache.
UpdateTimestampsCache	Tracks the timestamps of the most recent updates to particular tables.

Exception Summary

CacheException	Something went wrong in the cache
NoCachingEnabledException	Implementation of NoCachingEnabledException.

Package org.hibernate.cache Description

This package defines APIs/SPIs and implementations for the Hibernate second-level cache.

The legacy (and now deprecated) approach to caching is defined by the CacheProvider and Cache interfaces as well as the CacheConcurrencyStrategy interface along with the various implementations of all these interfaces. In that scheme, a CacheProvider defined how to configure and perform lifecycle operations in regards to a particular underlying caching library; it also defined how to build Cache instances which in turn defined how to access the "regions" of the underlying cache instance. For entity and collection data cache regions, CacheConcurrencyStrategy wrapped access to those cache regions to apply transactional/concurrent access semantics.

The improved approach is based on RegionFactory, the various Region specializations and the two access strategies contracts (EntityRegionAccessStrategy and CollectionRegionAccessStrategy). The general approach here is that RegionFactory defined how to configure and perform lifecycle operations in regards to a particular underlying caching library (or libraries). RegionFactory also defines how to build specialized Region instances based on the type of data we will be storing in that given region. The fact that RegionFactory is asked to build specialized regions (as opposed to just general access) is the first improvement over the legacy scheme. The second improvement is the fact that the regions (well the ones like entity and collection regions that are responsible for storing transactional data) are asked to build their own access strategies (see EntityRegion.buildAccessStrategy(org.hibernate.cache.access.AccessType) and CollectionRegion.buildAccessStrategy(org.hibernate.cache.access.AccessType)).