001/*
002 * Copyright (c) 2008, 2009, 2011 Oracle, Inc. All rights reserved.
003 *
004 * This program and the accompanying materials are made available under the
005 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
006 * which accompanies this distribution.  The Eclipse Public License is available
007 * at http://www.eclipse.org/legal/epl-v10.html and the Eclipse Distribution License
008 * is available at http://www.eclipse.org/org/documents/edl-v10.php.
009 */
010package javax.persistence;
011
012import java.lang.annotation.Repeatable;
013import java.lang.annotation.Retention;
014import java.lang.annotation.Target;
015
016import static java.lang.annotation.ElementType.*;
017import static java.lang.annotation.RetentionPolicy.RUNTIME;
018
019/**
020 * Expresses a dependency on an {@link EntityManagerFactory} and its
021 * associated persistence unit.
022 *
023 * @since Java Persistence 1.0
024 */
025@Target({TYPE, METHOD, FIELD})
026@Retention(RUNTIME)
027@Repeatable(PersistenceUnits.class)
028public @interface PersistenceUnit {
029  /**
030   * (Optional) The name by which the entity manager factory is to be accessed
031   * in the environment referencing context;  not needed when
032   * dependency injection is used.
033   *
034   * @return name
035   */
036  String name() default "";
037
038  /**
039   * (Optional) The name of the persistence unit as defined in the
040   * <code>persistence.xml</code> file. If specified, the
041   * persistence unit for the entity manager factory that is
042   * accessible in JNDI must have the same name.
043   *
044   * @return unit name
045   */
046  String unitName() default "";
047}