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.

Since:

Java Persistence 2.0

Method Summary

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,
           Object primaryKey)

Remove the data for the given entity from the cache.

Parameters:

cls - entity class

primaryKey - primary key

evict

void evict(Class cls)

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

Parameters:

cls - entity class

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

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