001    /**
002     * Copyright (c) 2000-2013 Liferay, Inc. All rights reserved.
003     *
004     * The contents of this file are subject to the terms of the Liferay Enterprise
005     * Subscription License ("License"). You may not use this file except in
006     * compliance with the License. You can obtain a copy of the License by
007     * contacting Liferay, Inc. See the License for the specific language governing
008     * permissions and limitations under the License, including but not limited to
009     * distribution rights of the Software.
010     *
011     *
012     *
013     */
014    
015    package com.liferay.portal.kernel.notifications;
016    
017    import java.util.Comparator;
018    
019    /**
020     * @author Edward Han
021     */
022    public class NotificationEventComparator
023            implements Comparator<NotificationEvent> {
024    
025            public NotificationEventComparator() {
026                    this(true);
027            }
028    
029            public NotificationEventComparator(boolean ascending) {
030                    _ascending = ascending;
031            }
032    
033            @Override
034            public int compare(
035                    NotificationEvent notificationEvent1,
036                    NotificationEvent notificationEvent2) {
037    
038                    if (notificationEvent1.equals(notificationEvent2)) {
039                            return 0;
040                    }
041    
042                    long value =
043                            notificationEvent1.getDeliverBy() -
044                                    notificationEvent2.getDeliverBy();
045    
046                    if (value == 0) {
047                            value =
048                                    notificationEvent1.getTimestamp() -
049                                            notificationEvent2.getTimestamp();
050                    }
051    
052                    if (value == 0) {
053                            value =
054                                    notificationEvent1.hashCode() - notificationEvent2.hashCode();
055                    }
056    
057                    if (_ascending) {
058                            return (int)value;
059                    }
060                    else {
061                            return (int)-value;
062                    }
063            }
064    
065            private boolean _ascending;
066    
067    }