Java tutorial
/******************************************************************************* * Copyright (c) 2008 - 2013 Oracle Corporation. All rights reserved. * * This program and the accompanying materials are made available under the * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0 * which accompanies this distribution. * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html * and the Eclipse Distribution License is available at * http://www.eclipse.org/org/documents/edl-v10.php. * * Contributors: * Linda DeMichiel - Java Persistence 2.1 * Linda DeMichiel - Java Persistence 2.0 * ******************************************************************************/ package javax.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; import static javax.persistence.FetchType.LAZY; /** * Specifies a collection of instances of a basic type or embeddable * class. * Must be specified if the collection is to be mapped by * means of a collection table. * * <pre> * Example: * * @Entity public class Person { * @Id protected String ssn; * protected String name; * ... * @ElementCollection * protected Set<String> nickNames = new HashSet(); * ... * } * </pre> * * @since Java Persistence 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 * paramterized 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 EAGER strategy is a requirement on * the persistence provider runtime that the collection elements * must be eagerly fetched. The LAZY strategy is a hint to the * persistence provider runtime. */ FetchType fetch() default LAZY; }