/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* License: GNU Lesser General Public License (LGPL), version 2.1 or later.
* See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
*/
package org.hibernate.annotations;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import org.hibernate.tuple.AnnotationValueGeneration;
/**
* Marks an annotation type as a generator annotation type.
* <p>
* Adding a generator annotation to an entity property causes the value of the property to be generated upon insert
* or update of the owning entity. Not more than one generator annotation may be placed on a given property.
* <p>
* Each generator annotation type is associated with a {@link AnnotationValueGeneration} which implements the strategy
* for generating the value. Generator annotation types may define arbitrary custom attributes, e.g. allowing the
* client to configure the generation timing (if applicable) or other settings taking an effect on the value generation.
* The corresponding implementation can retrieve these settings from the annotation instance passed to
* {@link AnnotationValueGeneration#initialize(java.lang.annotation.Annotation, Class)}.
* <p>
* Custom generator annotation types must have retention policy {@link RetentionPolicy#RUNTIME}.
* @author Gunnar Morling
*/
@Target( value = ElementType.ANNOTATION_TYPE )
@Retention( RetentionPolicy.RUNTIME )
public @interface ValueGenerationType {
/**
* The type of value generation associated with the annotated value generator annotation type. The referenced
* generation type must be parameterized with the type of the given generator annotation.
*
* @return the value generation type
*/
Class<? extends AnnotationValueGeneration<?>> generatedBy();
}