All Superinterfaces:

jakarta.persistence.Cache

All Known Subinterfaces:

CacheImplementor

All Known Implementing Classes:

DisabledCaching, EnabledCaching
```
public interface Cache
extends jakarta.persistence.Cache
```
An API for directly querying and managing the second level cache.
Hibernate has two levels of caching:
- The first-level cache is better known as the persistence context. It's the collection of managed entity instances associated with an open Session.
- The second-level cache is shared between all sessions belonging to a given SessionFactory. It stores the state of an entity instance in a destructured format, as a tuple of persistent attribute values.
By nature, a second-level cache tends to undermine the ACID properties of transaction processing in a relational database. A second-level cache is often by far the easiest way to improve the performance of a system, but only at the cost of making it much more difficult to reason about concurrency. And so the cache is a potential source of bugs which are difficult to isolate and reproduce.
Therefore, only entities and collection roles explicitly annotated Cacheable or Cache are eligible for storage in the second-level cache, and so by default the state of an entity is always retrieved from the database when requested.
Hibernate segments the second-level cache into named regions, one for each mapped entity hierarchy or collection role, each with its own policies for expiry, persistence, and replication, which must be configured externally to Hibernate. An entity hierarchy or collection role may be explicitly assigned a region using the Cache annotation, but, by default, the region name is just the name of the entity class or collection role.
The appropriate policies depend on the kind of data an entity represents. For example, a program might have different caching policies for "reference" data, for transactional data, and for data used for analytics. Ordinarily, the implementation of those policies is the responsibility of the cache provider and is transparent to code which makes use of a Hibernate Session. At worst, interaction with the cache may be controlled by specification of an explicit CacheMode.
Very occasionally, it's necessary or advantageous to control the cache explicitly via programmatic eviction, using, for example, evictEntityData(Class) to evicts a whole cache region, or evictEntityData(Class, Object), to evict a single item.
If multiple entities or roles are mapped to the same cache region, they share policies and even the same FIFO-type expiry queue (if any). This sounds useful, but comes with the downside that evictEntityData(Class) for any one of the entities evicts all entities mapped to the same region. It's therefore much more common to have a distinct region for each entity and role.
None of the operations of this interface respect any isolation or transactional semantics associated with the underlying caches. In particular, eviction via the methods of this interface causes an immediate "hard" removal outside any current transaction and/or locking scheme.
The Cache annotation also specifies a CacheConcurrencyStrategy, a policy governing access to the second-level cache by concurrent transactions. Either:
- read-only access for immutable data,
- read/write access with no locking, when concurrent updates are extremely improbable,
- read/write access using soft locks when concurrent updates are possible but not common, or
- transactional access when concurrent updates are frequent.
It's important to always explicitly specify an appropriate policy, taking into account the expected patterns of data access, most importantly, the frequency of updates.
See Also:

Cache, CacheConcurrencyStrategy

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`boolean`	`containsCollection(String role, Object ownerIdentifier)`	Determine whether the cache contains an item for the collection with the given role and given identifier.
`boolean`	`containsEntity(Class<?> entityClass, Object identifier)`	Determine whether the cache contains an item for the entity of the given type, and with the given identifier.
`boolean`	`containsEntity(String entityName, Object identifier)`	Determine whether the cache contains an item for the entity of the type with the given name, and with the given identifier.
`boolean`	`containsQuery(String regionName)`	Determine whether the given region name contains cached query results.
`default void`	`evictAll()`
`default void`	`evictAllRegions()`	Evict all cached data from every cache region.
`void`	`evictCollectionData()`	Evict all cache data from every cache region to which some collection role is assigned.
`void`	`evictCollectionData(String role)`	Evict all cached data from the cache region to which the given collection role is assigned.
`void`	`evictCollectionData(String role, Object ownerIdentifier)`	Evict the cached item for the collection with the given role and given identifier, if there is any such item in the cache.
`void`	`evictDefaultQueryRegion()`	Evict all cached query results from the default region.
`void`	`evictEntityData()`	Evict all cached data from every cache region to which any entity type is assigned.
`void`	`evictEntityData(Class<?> entityClass)`	Evict all cached data from the cache region to which the given entity type is assigned.
`void`	`evictEntityData(Class<?> entityClass, Object identifier)`	Evicts the cached item for the entity of the given type, and with the given identifier, if there is any such item in the cache.
`void`	`evictEntityData(String entityName)`	Evict all cached data from the cache region to which the given named entity type is assigned.
`void`	`evictEntityData(String entityName, Object identifier)`	Evict the cached item for the entity of the type with the given name, and with the given identifier, if there is any such item in the cache.
`void`	`evictNaturalIdData()`	Evict all cached natural id mappings for every entity type.
`void`	`evictNaturalIdData(Class<?> entityClass)`	Evict all cached natural id mappings for the given entity type.
`void`	`evictNaturalIdData(String entityName)`	Evict all cached natural id mappings for the entity type with the given name.
`void`	`evictQueryRegion(String regionName)`	Evict all cached query results from the region with the given name.
`void`	`evictQueryRegions()`	Evict all cached query results from every region.
`void`	`evictRegion(String regionName)`	Evict all cached data from the named cache region.
`SessionFactory`	`getSessionFactory()`	The `SessionFactory` to which this `Cache` belongs.

Methods inherited from interface jakarta.persistence.Cache
contains, evict, evict, unwrap

- Method Detail
  - getSessionFactory
```
SessionFactory getSessionFactory()
```
    The SessionFactory to which this Cache belongs.
    
    Returns:
    
    The SessionFactory
  - containsEntity
```
boolean containsEntity(Class<?> entityClass,
                       Object identifier)
```
    Determine whether the cache contains an item for the entity of the given type, and with the given identifier.
    
    Parameters:
    
    entityClass - The entity type
    
    identifier - The entity identifier
    
    Returns:
    
    True if the underlying cache contains corresponding data; false otherwise.
  - containsEntity
```
boolean containsEntity(String entityName,
                       Object identifier)
```
    Determine whether the cache contains an item for the entity of the type with the given name, and with the given identifier.
    
    Parameters:
    
    entityName - The entity name
    
    identifier - The entity identifier
    
    Returns:
    
    True if the underlying cache contains corresponding data; false otherwise.
  - evictEntityData
```
void evictEntityData(Class<?> entityClass,
                     Object identifier)
```
    Evicts the cached item for the entity of the given type, and with the given identifier, if there is any such item in the cache.
    
    Parameters:
    
    entityClass - The entity type
    
    identifier - The entity identifier
    
    Since:
    
    5.3
  - evictEntityData
```
void evictEntityData(String entityName,
                     Object identifier)
```
    Evict the cached item for the entity of the type with the given name, and with the given identifier, if there is any such item in the cache.
    
    Parameters:
    
    entityName - The entity name
    
    identifier - The entity identifier
    
    Since:
    
    5.3
  - evictEntityData
```
void evictEntityData(Class<?> entityClass)
```
    Evict all cached data from the cache region to which the given entity type is assigned. Thus, every cached item for the given entity type will be evicted, along with any cached items for any other entity type assigned to the same cache region.
    
    Parameters:
    
    entityClass - The entity type
    
    Since:
    
    5.3
  - evictEntityData
```
void evictEntityData(String entityName)
```
    Evict all cached data from the cache region to which the given named entity type is assigned. Thus, every cached item for the given entity type will be evicted, along with any cached items for any other entity type assigned to the same cache region.
    
    Parameters:
    
    entityName - The entity name
    
    Since:
    
    5.3
  - evictEntityData
```
void evictEntityData()
```
    Evict all cached data from every cache region to which any entity type is assigned.
    
    Since:
    
    5.3
  - evictNaturalIdData
```
void evictNaturalIdData(Class<?> entityClass)
```
    Evict all cached natural id mappings for the given entity type.
    
    Parameters:
    
    entityClass - The entity type
    
    Since:
    
    5.3
  - evictNaturalIdData
```
void evictNaturalIdData(String entityName)
```
    Evict all cached natural id mappings for the entity type with the given name.
    
    Parameters:
    
    entityName - The entity name
    
    Since:
    
    5.3
  - evictNaturalIdData
```
void evictNaturalIdData()
```
    Evict all cached natural id mappings for every entity type.
    
    Since:
    
    5.3
  - containsCollection
```
boolean containsCollection(String role,
                           Object ownerIdentifier)
```
    Determine whether the cache contains an item for the collection with the given role and given identifier.
    
    Parameters:
    
    role - The name of the collection role in the form package.OwnerEntityName.collectionPropertyName
    
    ownerIdentifier - The identifier of the owning entity
    
    Returns:
    
    True if the underlying cache contains corresponding data; false otherwise.
  - evictCollectionData
```
void evictCollectionData(String role,
                         Object ownerIdentifier)
```
    Evict the cached item for the collection with the given role and given identifier, if there is any such item in the cache.
    
    Parameters:
    
    role - The name of the collection role in the form package.OwnerEntityName.collectionPropertyName
    
    ownerIdentifier - The identifier of the owning entity
    
    Since:
    
    5.3
  - evictCollectionData
```
void evictCollectionData(String role)
```
    Evict all cached data from the cache region to which the given collection role is assigned.
    
    Parameters:
    
    role - The name of the collection role in the form package.OwnerEntityName.collectionPropertyName
    
    Since:
    
    5.3
  - evictCollectionData
```
void evictCollectionData()
```
    Evict all cache data from every cache region to which some collection role is assigned.
    
    Since:
    
    5.3
  - containsQuery
```
boolean containsQuery(String regionName)
```
    Determine whether the given region name contains cached query results.
    
    Parameters:
    
    regionName - The name of a cache region to which some query is assigned
    
    Returns:
    
    True if the underlying cache contains corresponding data; false otherwise.
  - evictDefaultQueryRegion
```
void evictDefaultQueryRegion()
```
    Evict all cached query results from the default region.
  - evictQueryRegion
```
void evictQueryRegion(String regionName)
```
    Evict all cached query results from the region with the given name.
    
    Parameters:
    
    regionName - The cache name associated to the queries being cached.
  - evictQueryRegions
```
void evictQueryRegions()
```
    Evict all cached query results from every region.
  - evictRegion
```
void evictRegion(String regionName)
```
    Evict all cached data from the named cache region.
    
    Since:
    
    5.3
  - evictAll
```
default void evictAll()
```
    Specified by:
    
    evictAll in interface jakarta.persistence.Cache
  - evictAllRegions
```
default void evictAllRegions()
```
    Evict all cached data from every cache region.

Interface Cache

Method Summary

Methods inherited from interface jakarta.persistence.Cache

Method Detail

getSessionFactory

containsEntity

containsEntity

evictEntityData

evictEntityData

evictEntityData

evictEntityData

evictEntityData

evictNaturalIdData

evictNaturalIdData

evictNaturalIdData

containsCollection

evictCollectionData

evictCollectionData

evictCollectionData

containsQuery

evictDefaultQueryRegion

evictQueryRegion

evictQueryRegions

evictRegion

evictAll

evictAllRegions