| /* |
| * 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: |
| // 06/15/2009 Andrei Ilitchev |
| // - JPA 2.0 - OrderedList support. |
| package org.eclipse.persistence.testing.models.orderedlist; |
| |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.Comparator; |
| import java.util.List; |
| |
| import org.eclipse.persistence.internal.helper.IndexedObject; |
| import org.eclipse.persistence.internal.queries.OrderedListContainerPolicy; |
| |
| /** |
| * Example of a custom OrderedListContainerPolicy that overrides correctOrderList method, |
| * which used in case orderCorrectionType is OrderCorrectionType.READ or OrderCorrectionType.READ_WRITE |
| * when the list of order indexes read from the data base is invalid. |
| * OrderedListContainerPolicy.correctOrderList method puts null in the beginning of the repaired list, |
| * this class put nulls in the end. |
| * |
| * @see org.eclipse.persistence.internal.helper.IndexedObject |
| * @see org.eclipse.persistence.internal.queries.OrderedListContainerPolicy |
| */ |
| public class NullsLastOrderedListContainerPolicy extends OrderedListContainerPolicy { |
| static class NullsLastComparator implements Comparator<IndexedObject> { |
| /* |
| * Compares indexes, null is greater than any non-null. |
| */ |
| @Override |
| public int compare(IndexedObject indexedObject1, IndexedObject indexedObject2) { |
| Integer index1 = indexedObject1.getIndex(); |
| Integer index2 = indexedObject2.getIndex(); |
| if(index1 == null) { |
| if(index2 == null) { |
| return 0; |
| } else { |
| return 1; |
| } |
| } else { |
| if(index2 == null) { |
| return -1; |
| } else { |
| return index1.compareTo(index2); |
| } |
| } |
| } |
| } |
| static NullsLastComparator nullsLastComparator = new NullsLastComparator(); |
| |
| /** |
| * INTERNAL: |
| * Construct a new policy. |
| */ |
| public NullsLastOrderedListContainerPolicy() { |
| super(); |
| } |
| |
| /** |
| * INTERNAL: |
| * Construct a new policy for the specified class. |
| */ |
| public NullsLastOrderedListContainerPolicy(Class containerClass) { |
| super(containerClass); |
| } |
| |
| /** |
| * INTERNAL: |
| * Construct a new policy for the specified class name. |
| */ |
| public NullsLastOrderedListContainerPolicy(String containerClassName) { |
| super(containerClassName); |
| } |
| |
| @Override |
| public List correctOrderList(List<IndexedObject> indexedObjects) { |
| Collections.sort(indexedObjects, nullsLastComparator); |
| int size = indexedObjects.size(); |
| List objects = new ArrayList(size); |
| for(int i=0; i < size; i++) { |
| objects.add(indexedObjects.get(i).getObject()); |
| } |
| return objects; |
| } |
| } |