/*
* Copyright (c) 2008, 2009 Sun Microsystems. 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 2.0 - Version 2.0 (October 1, 2009)
* Specification available from http://jcp.org/en/jsr/detail?id=317
*/
// $Id: Version.java 20957 2011-06-13 09:58:51Z stliu $
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;
/**
* 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 {
}