org.eclipse.persistence.annotations

Annotation Type Cache

@Target(value=TYPE)
@Retention(value=RUNTIME)
public @interface Cache

The Cache annotation is used to configure the EclipseLink object cache. By default EclipseLink uses a shared object cache to cache all objects. The caching type and options can be configured on a per class basis to allow optimal caching.

This includes options for configuring the type of caching, setting the size, disabling the shared cache, expiring objects, refreshing, and cache coordination (clustering).

A Cache annotation may be defined on an Entity or MappedSuperclass. In the case of inheritance, a Cache annotation should only be defined on the root of the inheritance hierarchy.

See Also:

CacheType, CacheCoordinationType, ClassDescriptor, CacheInvalidationPolicy

Author:

Guy Pelletier

Since:

Oracle TopLink 11.1.1.0.0

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
boolean	alwaysRefresh (Optional) Force all queries that go to the database to always refresh the cache.
CacheCoordinationType	coordinationType (Optional) The cache coordination mode.
DatabaseChangeNotificationType	databaseChangeNotificationType (Optional) The database change notification mode.
boolean	disableHits (Optional) Setting to true will force all queries to bypass the cache for hits but still resolve against the cache for identity.
int	expiry (Optional) Expire cached instance after a fix period of time (ms).
TimeOfDay	expiryTimeOfDay (Optional) Expire cached instance a specific time of day.
CacheIsolationType	isolation (Optional) Controls the level of caching this Entity will use.
boolean	refreshOnlyIfNewer (Optional) For all queries that go to the database, refresh the cache only if the data received from the database by a query is newer than the data in the cache (as determined by the optimistic locking field).
boolean	shared Deprecated. As of Eclipselink 2.2. See the attribute 'isolation'
int	size (Optional) The size of cache to use.
CacheType	type (Optional) The type of cache to use.

Element Detail

type

public abstract CacheType type

(Optional) The type of cache to use. The default is SOFT_WEAK.

Default:

org.eclipse.persistence.annotations.CacheType.SOFT_WEAK

size

public abstract int size

(Optional) The size of cache to use. The default is 100.

Default:

100

shared

@Deprecated
public abstract boolean shared

Deprecated. As of Eclipselink 2.2. See the attribute 'isolation'

(Optional) Cached instances in the shared cache, or only a per EntityManager isolated cache. The default is shared.

Default:

true

isolation

public abstract CacheIsolationType isolation

(Optional) Controls the level of caching this Entity will use. The default is CacheIsolationType.SHARED which has EclipseLink Caching all Entities in the Shared Cache.

See Also:

CacheIsolationType

Default:

org.eclipse.persistence.config.CacheIsolationType.SHARED

expiry

public abstract int expiry

(Optional) Expire cached instance after a fix period of time (ms). Queries executed against the cache after this will be forced back to the database for a refreshed copy. By default there is no expiry.

Default:

-1

expiryTimeOfDay

public abstract TimeOfDay expiryTimeOfDay

(Optional) Expire cached instance a specific time of day. Queries executed against the cache after this will be forced back to the database for a refreshed copy.

Default:

@org.eclipse.persistence.annotations.TimeOfDay(specified=false)

alwaysRefresh

public abstract boolean alwaysRefresh

(Optional) Force all queries that go to the database to always refresh the cache. Default is false. Consider disabling the shared cache instead of forcing refreshing.

Default:

false

refreshOnlyIfNewer

public abstract boolean refreshOnlyIfNewer

(Optional) For all queries that go to the database, refresh the cache only if the data received from the database by a query is newer than the data in the cache (as determined by the optimistic locking field). This is normally used in conjunction with alwaysRefresh, and by itself it only affect explicit refresh calls or queries. Default is false.

Default:

false

disableHits

public abstract boolean disableHits

(Optional) Setting to true will force all queries to bypass the cache for hits but still resolve against the cache for identity. This forces all queries to hit the database.

Default:

false

coordinationType

public abstract CacheCoordinationType coordinationType

(Optional) The cache coordination mode. Note that cache coordination must also be configured for the persistence unit/session.

Default:

org.eclipse.persistence.annotations.CacheCoordinationType.SEND_OBJECT_CHANGES

databaseChangeNotificationType

public abstract DatabaseChangeNotificationType databaseChangeNotificationType

(Optional) The database change notification mode. Note that database event listener must also be configured for the persistence unit/session.

Default:

org.eclipse.persistence.annotations.DatabaseChangeNotificationType.INVALIDATE