/******************************************************************************* | |
* 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.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(ClassExtrator) | |
*/ | |
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 Class extractClassFromRow(Record databaseRow, Session session); | |
/** | |
* Allow for any initialization. | |
*/ | |
public void initialize(ClassDescriptor descriptor, Session session) throws DescriptorException { | |
// Do nothing by default. | |
} | |
} |