JPA Annotation

MapKeyClass

Target: METHOD, FIELD
Implemented Interfaces:
Annotation
Specifies the type of the map key for associations of type java.util.Map. The map key can be a basic type, an embeddable class, or an entity. If the map is specified using Java generics, the MapKeyClass annotation and associated type need not be specified; otherwise they must be specified.

The MapKeyClass annotation is used in conjunction with ElementCollection or one of the collection-valued relationship annotations (OneToMany or ManyToMany). The MapKey annotation is not used when MapKeyClass is specified and vice versa.

Example 1:

 {@snippet :
See Also:
ElementCollection
OneToMany
ManyToMany
Since:
JPA 2.0

Public Annotation Attributes

Class<?> value default null
(Required) The type of the map key.
Since:
JPA 2.0