javax.persistence

Interface Cache

public interface Cache

Interface used to interact with the second-level cache. If a cache is not in use, the methods of this interface have no effect, except for contains, which returns false.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	contains(Class<?> cls, Object primaryKey) Whether the cache contains data for the given entity.
void	evict(Class<?> cls) Remove the data for entities of the specified class (and its subclasses) from the cache.
void	evict(Class<?> cls, Object primaryKey) Remove the data for the given entity from the cache.
void	evictAll() Clear the cache.
<T> T	unwrap(Class<T> cls) Return an object of the specified type to allow access to the provider-specific API.

Method Detail

contains

boolean contains(Class<?> cls,
               Object primaryKey)

Whether the cache contains data for the given entity.

Parameters:

cls - entity class

primaryKey - primary key

Returns:

boolean indicating whether the entity is in the cache

evict

void evict(Class<?> cls)

Remove the data for entities of the specified class (and its subclasses) from the cache.

Parameters:

cls - entity class

evict

void evict(Class<?> cls,
         Object primaryKey)

Remove the data for the given entity from the cache.

Parameters:

cls - entity class

primaryKey - primary key

evictAll

void evictAll()

Clear the cache.

unwrap

<T> T unwrap(Class<T> cls)

Return an object of the specified type to allow access to the provider-specific API. If the provider's Cache implementation does not support the specified class, the PersistenceException is thrown.

Type Parameters:

T - type of the class

Parameters:

cls - the class of the object to be returned. This is normally either the underlying Cache implementation class or an interface that it implements.

Returns:

an instance of the specified class

Throws:

PersistenceException - if the provider does not support the call