/*
* 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.
ElementType.
METHOD;
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.
*
* <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> 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> 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>.
*
* <pre>
* Example:
*
* @Version
* @Column(name="OPTLOCK")
* protected int getVersionNum() { return versionNum; }
* </pre>
*
* @since Java Persistence 1.0
*/
@
Target({
METHOD,
FIELD })
@
Retention(
RUNTIME)
public @interface
Version {
}