http://www.avaje.org/persistence-api: Packaging parent for Avaje OSS projects.
  • Rob Bygrave 
/*
 * Copyright (c) 2008, 2009, 2011 Oracle, Inc. 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.
 */
package javax.persistence;

import java.lang.annotation.Retention;
import java.lang.annotation.Target;

import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;


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, Integer, short,
Short, long, Long,
java.sql.Timestamp.



   Example:
   @Version
   int version;



Since:Java Persistence 1.0
/**
 * 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.
 * <p>
 * <p> Only a single <code>Version</code> property or field
 * should be used per class; applications that use more than one
 * <code>Version</code> property or field will not be portable.
 * <p>
 * <p> The <code>Version</code> property should be mapped to
 * the primary table for the entity class; applications that
 * map the <code>Version</code> property to a table other than
 * the primary table will not be portable.
 * <p>
 * <p> The following types are supported for version properties:
 * <code>int</code>, <code>Integer</code>, <code>short</code>,
 * <code>Short</code>, <code>long</code>, <code>Long</code>,
 * <code>java.sql.Timestamp</code>.
 * <p>
 * <pre>
 *    Example:
 *
 *    &#064;Version
 *    int version;
 * </pre>
 *
 * @since Java Persistence 1.0
 */
@Target({FIELD})
@Retention(RUNTIME)
public @interface Version {
}