| /* |
| * Copyright (c) 1998, 2021 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 v. 2.0 which is available at |
| * http://www.eclipse.org/legal/epl-2.0, |
| * or the Eclipse Distribution License v. 1.0 which is available at |
| * http://www.eclipse.org/org/documents/edl-v10.php. |
| * |
| * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause |
| */ |
| |
| // Contributors: |
| // Oracle - initial API and implementation from Oracle TopLink |
| package org.eclipse.persistence.descriptors; |
| |
| import org.eclipse.persistence.exceptions.*; |
| import org.eclipse.persistence.sessions.*; |
| |
| /** |
| * <p><b>Purpose</b>: |
| * Abstract class to allow complex inheritance support. Typically class indicators are used to define inheritance in the database, |
| * however in complex cases the class type may be determined through another mechanism. |
| * The class extractor must be able to determine and return the class type from the database row. |
| * |
| * @see org.eclipse.persistence.descriptors.InheritancePolicy#setClassExtractor(ClassExtractor) |
| */ |
| public abstract class ClassExtractor { |
| |
| /** |
| * Extract/compute the class from the database row and return the class. |
| * Map is used as the public interface to database row, the key is the field name, |
| * the value is the database value. |
| */ |
| public abstract <T> Class<T> extractClassFromRow(org.eclipse.persistence.sessions.Record databaseRow, Session session); |
| |
| /** |
| * Allow for any initialization. |
| */ |
| public void initialize(ClassDescriptor descriptor, Session session) throws DescriptorException { |
| // Do nothing by default. |
| } |
| } |