io.ebean.annotation

Annotation Type Cache

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

Specify the default cache use specific entity type.

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
boolean	enableBeanCache Set this to false to disable the use of bean cache.
boolean	enableQueryCache Set this to true to enable the use of query cache.
String[]	naturalKey Specify the properties that is a natural unique identifier for the bean.
boolean	nearCache If set to true additionally use a near cache (for Redis and similar L2 cache options).
boolean	readOnly When set to true the beans returned from a query will default to be readOnly.
String	region Specify a named cache region.

Element Detail

nearCache

public abstract boolean nearCache

If set to true additionally use a near cache (for Redis and similar L2 cache options).

This does not apply to query caches (as they are always near caches) but applies to the bean caching (bean cache, natural key cache and collection ids cache).

Near caches are fast in that they are in local memory avoid going over the network to the remote cache with the downside of using more local memory and increasing the cache invalidation costs for updates and deletes (as cache invalidations need to propagate with near caching turned on).

Near caching is best with relatively many reads to few writes.

Default:

false

enableQueryCache

public abstract boolean enableQueryCache

Set this to true to enable the use of query cache.

By default query caching is disabled as the query cache invalidates frequently and so it is typically used for specific bean types and cases.

Default:

false

enableBeanCache

public abstract boolean enableBeanCache

Set this to false to disable the use of bean cache.

By default bean caching is expected so this defaults to true. We might set this to false on a bean type that we want to use query caching but no bean caching (and this is expected to be a rare case).

When bean caching is enabled by default "find by id" and "find by unique natural key" queries will try to use the bean cache. We use Query.setUseCache(boolean) with false for the case when we do NOT want to use the bean cache.

Default:

true

naturalKey

public abstract String[] naturalKey

Specify the properties that is a natural unique identifier for the bean.

When a findOne() query is used with this property as the sole expression then there will be a lookup into the L2 natural key cache.

Default:

{}

readOnly

public abstract boolean readOnly

When set to true the beans returned from a query will default to be readOnly.

If the bean is readOnly and has no relationships then it may be sharable.

If you try to modify a readOnly bean it will throw an IllegalStateException.

Default:

false

region

public abstract String region

Specify a named cache region.

Regions can be turned on and off dynamically at runtime.

Depending on the cache implementation a region can potentially have different deployment targets - for example, with the Ebean redis cache a region could be configured to use a different redis server.

The "default" region is called r0.

Default:

"r0"