Annotation Interface GenericGenerator

@Target({METHOD,FIELD,TYPE,PACKAGE})
@Retention(RUNTIME)
@Incubating
public @interface GenericGenerator

Specifies a generator used for generating entity identifiers, allowing the use of custom identifier generation strategies going beyond those provided by the four standard JPA-defined generation types.

When @GenericGenerator directly annotates a field, the @GeneratedValue annotation is not required:

@Id
@GenericGenerator(type = CustomUuidGenerator.class)
private String uuid;

On the other hand, when @GenericGenerator annotates a class or package, @GeneratedValue must be applied to the generated id field:

@Entity
@GenericGenerator(type = CustomUuidGenerator.class)
class Record {
    @Id
    @GeneratedValue
    private String uuid;
    ...
}

See Also:

• IdGeneratorType

API Note:

This annotation has been substantially reworked after a period of being marked as deprecated, and its semantics have changed significantly. Previously, it registered a named generator using legacy infrastructure. It is now redefined as an IdGeneratorType and the deprecation has been reversed. Nevertheless, use of @GenericGenerator is still only recommended as a migrational bridge to the recommended approach of declaring a custom annotation for each kind of generator.

Required Element Summary

Required Elements

Modifier and Type	Required Element	Description
Class<? extends Generator>	type	The type of identifier generator, a class implementing Generator or, more commonly, IdentifierGenerator.

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element	Description
Parameter[]	parameters	Parameters to be passed to Configurable.configure(Type, Properties, ServiceRegistry) when the identifier generator is instantiated.

Element Details

type

Class<? extends Generator> type

The type of identifier generator, a class implementing Generator or, more commonly, IdentifierGenerator.

parameters

Parameter[] parameters

Parameters to be passed to Configurable.configure(Type, Properties, ServiceRegistry) when the identifier generator is instantiated.

API Note:

Use of @Parameter to configure a generator is verbose and completely lacks type safety—it's much better to use IdGeneratorType to define a custom annotation type carrying the configuration of the specific generator class.

Default:

{}