src/javax/persistence/PessimisticLockScope.java

/*******************************************************************************
 * 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 - Proposed Final Draft, Version 2.0 (August 31, 2009)
 *     Specification available from http://jcp.org/en/jsr/detail?id=317
 *
 * Java(TM) Persistence API, Version 2.0 - EARLY ACCESS
 * This is an implementation of an early-draft specification developed under the 
 * Java Community Process (JCP).  The code is untested and presumed not to be a  
 * compatible implementation of JSR 317: Java(TM) Persistence API, Version 2.0.   
 * We encourage you to migrate to an implementation of the Java(TM) Persistence 
 * API, Version 2.0 Specification that has been tested and verified to be compatible 
 * as soon as such an implementation is available, and we encourage you to retain 
 * this notice in any implementation of Java(TM) Persistence API, Version 2.0 
 * Specification that you distribute.
 ******************************************************************************/
package javax.persistence;

/**
 * Defines the values of the <code>javax.persistence.lock.scope</code>
 * property for pessimistic locking.  This property may be passed as
 * an argument to the methods of the {@link EntityManager},
 * {@link Query}, and {@link TypedQuery} interfaces that
 * allow lock modes to be specified or used with the
 * {@link NamedQuery} annotation.
 *
 * @since Java Persistence 2.0
 */
public enum PessimisticLockScope {

    /**
     * This value defines the default behavior for pessimistic locking.
     *
     * <p>The persistence provider must lock the database row(s) that
     * correspond to the non-collection-valued persistent state of
     * that instance.  If a joined inheritance strategy is used, or if
     * the entity is otherwise mapped to a secondary table, this
     * entails locking the row(s) for the entity instance in the
     * additional table(s).  Entity relationships for which the locked
     * entity contains the foreign key will also be locked, but not
     * the state of the referenced entities (unless those entities are
     * explicitly locked).  Element collections and relationships for
     * which the entity does not contain the foreign key (such as
     * relationships that are mapped to join tables or unidirectional
     * one-to-many relationships for which the target entity contains
     * the foreign key) will not be locked by default.
     */
    NORMAL,

    /**
     * In addition to the behavior for
     * <code>PessimisticLockScope.NORMAL</code>, element collections
     * and relationships owned by the entity that are contained in
     * join tables will be locked if the <code>javax.persistence.lock.scope</code>
     * property is specified with a value of
     * <code>PessimisticLockScope.EXTENDED</code>.
     */
    EXTENDED
}