jakarta.persistence.ElementCollection Maven / Gradle / Ivy
/*
* Copyright (c) 2008, 2023 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0,
* or the Eclipse Distribution License v. 1.0 which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
*/
// Contributors:
// Linda DeMichiel - 2.1
// Linda DeMichiel - 2.0
package jakarta.persistence;
import java.lang.annotation.Target;
import java.lang.annotation.Retention;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
/**
* Declares a collection of instances of a {@linkplain Basic basic type}
* or {@linkplain Embeddable embeddable class}. Must be specified if the
* collection is to be mapped by means of a collection table.
*
* The {@link CollectionTable} annotation specifies a mapping to a
* database table.
*
*
Example:
* {@snippet :
* @Entity
* public class Person {
* @Id
* protected String ssn;
* protected String name;
* ...
* @ElementCollection
* protected Set nickNames = new HashSet<>();
* ...
* }
* }
*
* @see CollectionTable
*
* @since 2.0
*/
@Target({ METHOD, FIELD })
@Retention(RUNTIME)
public @interface ElementCollection {
/**
* (Optional) The basic or embeddable class that is the element
* type of the collection. This element is optional only if the
* collection field or property is defined using Java generics,
* and must be specified otherwise. It defaults to the
* parameterized type of the collection when defined using
* generics.
*/
Class targetClass() default void.class;
/**
* (Optional) Whether the collection should be lazily loaded
* or must be eagerly fetched.
*
* - The {@link FetchType#EAGER EAGER} strategy is a
* requirement on the persistence provider runtime
* that the associated entity must be eagerly fetched.
*
- The {@link FetchType#LAZY LAZY} strategy is a hint
* to the persistence provider runtime.
*
*
* If not specified, defaults to {@code LAZY}.
*/
FetchType fetch() default FetchType.LAZY;
}