org.hibernate.annotations

Annotation Type Any

@Target(value={METHOD,FIELD})
 @Retention(value=RUNTIME)
public @interface Any

Defines a ToOne-style association pointing to one of several entity types depending on a local discriminator, as opposed to discriminated inheritance where the discriminator is kept as part of the entity hierarchy. For example, if you consider an Order entity containing Payment information where Payment might be of type CashPayment or CreditCardPayment the @Any approach would be to keep that discriminator and matching value on the Order itself. Thought of another way, the "foreign-key" really is made up of the value and discriminator (there is no physical foreign key here as databases do not support this):

    @Entity
    class Order {
        ...
        @Any( metaColumn = @Column( name="payment_type" ) )
        @AnyMetDef(
                idType = "long"
                metaValues = {
                        @MetaValue( value="C", targetEntity=CashPayment.class ),
                        @MetaValue( value="CC", targetEntity=CreditCardPayment.class ),
                }
        )
        pubic Payment getPayment() { ... }
    }
 }
 

Author:

Emmanuel Bernard, Steve Ebersole

See Also:

AnyMetaDef

Required Element Summary

Required Elements

Modifier and Type	Required Element and Description
Column	metaColumn Identifies the discriminator column.

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
FetchType	fetch Defines whether the value of the field or property should be lazily loaded or must be eagerly fetched.
String	metaDef Metadata definition used.
boolean	optional Whether the association is optional.

Element Detail

metaColumn

public abstract Column metaColumn

Identifies the discriminator column. This column will hold the value that identifies the targeted entity.

metaDef

public abstract String metaDef

Metadata definition used. If defined, should point to a @AnyMetaDef name If not defined, the local (ie in the same field or property) @AnyMetaDef is used

Default:

""

fetch

public abstract FetchType fetch

Defines whether the value of the field or property should be lazily loaded or must be eagerly fetched. The EAGER strategy is a requirement on the persistence provider runtime that the value must be eagerly fetched. The LAZY strategy is applied when bytecode enhancement is used. If not specified, defaults to EAGER.

Default:

javax.persistence.FetchType.EAGER

optional

public abstract boolean optional

Whether the association is optional. If set to false then a non-null relationship must always exist.

Default:

true