foundation/org.eclipse.persistence.core/src/org/eclipse/persistence/config/PessimisticLock.java

/*******************************************************************************
 * Copyright (c) 1998, 2013 Oracle and/or its affiliates. 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:
 *     Oracle - initial API and implementation from Oracle TopLink
 ******************************************************************************/  
package org.eclipse.persistence.config;

/**
 * PessimisticLock hint values.
 * 
 * The class contains all the valid values for QueryHints.PESSIMISTIC_LOCK query hint.
 * 
 * <p>JPA Query Hint Usage:
 * 
 * <p><code>query.setHint(QueryHints.PESSIMISTIC_LOCK, PessimisticLock.Lock);</code>
 * <p>or 
 * <p><code>@QueryHint(name=QueryHints.PESSIMISTIC_LOCK, value=PessimisticLock.Lock)</code>
 * 
 * <p>Hint values are case-insensitive.
 * "" could be used instead of default value PessimisticLock.DEFAULT.
 * 
 * @see QueryHints
 * 
 * <B>Note:</B> As of JPA 2.0 there is a standard way to configure pessimistic locking.
 * @see javax.persistence.LockModeType
 * @see javax.persistence.EntityManager (find(), refresh(), lock())
 * @see javax.persistence.Query (setLockMode())
 */
public class PessimisticLock {
    public static final String  NoLock = "NoLock";
    public static final String  Lock = "Lock";
    public static final String  LockNoWait = "LockNoWait";
 
    public static final String DEFAULT = NoLock;
}