Cache (EclipseLink 2.6.7, API Reference)

```
@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

Annotation Type Cache

Optional Element Summary

Element Detail

type

size

shared

isolation

expiry

expiryTimeOfDay

alwaysRefresh

refreshOnlyIfNewer

disableHits

coordinationType

databaseChangeNotificationType