Annotation Interface Cache


@Target({TYPE,METHOD,FIELD}) @Retention(RUNTIME) public @interface Cache
Marks a root entity or collection for second-level caching, and specifies:
  • a named cache region in which to store the state of instances of the entity or collection, and
  • an appropriate cache concurrency policy, given the expected data access patterns affecting the entity or collection.

This annotation should always be used in preference to the less useful JPA-defined annotation Cacheable, since JPA provides no means to specify anything about the semantics of the cache. Alternatively, it's legal, but redundant, for the two annotations to be used together.

Note that entity subclasses of a root entity with a second-level cache inherit the cache belonging to the root entity.

For example, the following entity is eligible for caching:

 @Entity
 @Cache(usage = NONSTRICT_READ_WRITE)
 public static class Person { ... }
 

Similarly, this collection is cached:

 @OneToMany(mappedBy = "person")
 @Cache(usage = NONSTRICT_READ_WRITE)
 private List<Phone> phones = new ArrayList<>();
 

Note that the second-level cache is disabled unless "hibernate.cache.region.factory_class" is explicitly specified, and so, by default, this annotation has no effect.

See Also:
  • Required Element Summary

    Required Elements
    Modifier and Type
    Required Element
    Description
    The appropriate concurrency policy for the annotated root entity or collection.
  • Optional Element Summary

    Optional Elements
    Modifier and Type
    Optional Element
    Description
    boolean
    When bytecode enhancement is used, and field-level lazy fetching is enabled, specifies whether lazy attributes of the entity are eligible for inclusion in the second-level cache, in the case where they happen to be loaded.
    The cache region name.
  • Element Details

    • region

      String region
      The cache region name.
      Default:
      ""
    • includeLazy

      boolean includeLazy
      When bytecode enhancement is used, and field-level lazy fetching is enabled, specifies whether lazy attributes of the entity are eligible for inclusion in the second-level cache, in the case where they happen to be loaded.

      By default, a loaded lazy field will be cached when second-level caching is enabled. If this is not desirable—if, for example, the field value is extremely large and only rarely accessed—then setting @Cache(includeLazy=false) will prevent it and other lazy fields of the annotated entity from being cached, and the lazy fields will always be retrieved directly from the database.

      See Also:
      Default:
      true