/*
* JBoss, Home of Professional Open Source.
* Copyright 2008, Red Hat Middleware LLC, and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.ejb.plugins.lock;
/**
* This class is an optmistic lock implementation.
* It locks tableFields and their values during transaction.
* Locked tableFields and their values are added to the WHERE clause of the
* UPDATE SQL statement when entity is stored.
* The following strategies are supported:
* - fixed group of tableFields
* Fixed group of tableFields is used for locking . The tableFields and their values are
* locked at the beginning of a transaction. The group name must match
* one of the entity's load-group-name.
* - modified strategy
* The tableFields that were modified during transaction are used as lock.
* All entity's field values are locked at the beginning of the transaction.
* The tableFields are locked only after its actual change.
* - read strategy
* The tableFields that were read/modified during transaction.
* All entity's field values are locked at the beginning of the transaction.
* The tableFields are locked only after they were accessed.
* - version-column strategy
* This adds additional version field of type java.lang.Long. Each update
* of the entity will increase the version value by 1.
* - timestamp-column strategy
* Adds additional timestamp column of type java.util.Date. Each update
* of the entity will set the field to the current time.
* - key-generator column strategy
* Adds additional column. The type is defined by user. The key generator
* is used to set the next value.
*
* Note: all optimistic locking related code should be rewritten when in the
* new CMP design.
*
* Note2: done.
*
* @author <a href="mailto:aloubyansky@hotmail.com">Alex Loubyansky</a>
* @version $Revision: 81030 $
*/
public final class JDBCOptimisticLock
extends NoLock
{
}