javax.persistence.Version Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of persistence-api Show documentation
There is a newer version: 1.0.2
/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * 
 * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
 * 
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License. You can obtain
 * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
 * or glassfish/bootstrap/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 * 
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
 * Sun designates this particular file as subject to the "Classpath" exception
 * as provided by Sun in the GPL Version 2 section of the License file that
 * accompanied this code.  If applicable, add the following below the License
 * Header, with the fields enclosed by brackets [] replaced by your own
 * identifying information: "Portions Copyrighted [year]
 * [name of copyright owner]"
 * 
 * Contributor(s):
 * 
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */
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;

/**
 * This annotation specifies the version field or property of 
 * an entity class that serves as its optimistic lock value. 
 * The version is used to ensure integrity when performing the 
 * merge operation and for optimistic concurrency control. 
 *
 *  Only a single Version property or field 
 * should be used per class; applications that use more than one 
 * Version property or field will not be portable. 
 * 
 * 
 The Version property should be mapped to 
 * the primary table for the entity class; applications that 
 * map the Version property to a table other than 
 * the primary table will not be portable.
 * 
 * 
 The following types are supported for version properties: 
 * int, {@link Integer}, short, 
 * {@link Short}, long, {@link Long}, 
 * {@link java.sql.Timestamp Timestamp}.
 *
 * 
 *    Example:
 *
 *    @Version
 *    @Column(name="OPTLOCK")
 *    protected int getVersionNum() { return versionNum; }
 * 
 *
 * @since Java Persistence 1.0
 */
@Target({METHOD, FIELD})
@Retention(RUNTIME)

public @interface Version {}