001 /*--------------------------------------------------------------------------+
002 $Id: DateUtils.java 29593 2010-08-09 16:01:20Z hummelb $
003 | |
004 | Copyright 2005-2010 Technische Universitaet Muenchen |
005 | |
006 | Licensed under the Apache License, Version 2.0 (the "License"); |
007 | you may not use this file except in compliance with the License. |
008 | You may obtain a copy of the License at |
009 | |
010 | http://www.apache.org/licenses/LICENSE-2.0 |
011 | |
012 | Unless required by applicable law or agreed to in writing, software |
013 | distributed under the License is distributed on an "AS IS" BASIS, |
014 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
015 | See the License for the specific language governing permissions and |
016 | limitations under the License. |
017 +--------------------------------------------------------------------------*/
018 package edu.tum.cs.commons.date;
019
020 import java.util.Collection;
021 import java.util.Collections;
022 import java.util.Date;
023
024 /**
025 * Utility methods for working on date objects.
026 *
027 * @author juergens
028 * @author $Author: hummelb $
029 * @version $Rev: 29593 $
030 * @levd.rating GREEN Hash: A327B6CB6CF8E826F60F8D16EBA23DEC
031 */
032 public class DateUtils {
033
034 /** Returns the latest date in a collection of dates */
035 public static Date getLatest(Collection<Date> dates) {
036 if (dates.isEmpty()) {
037 return null;
038 }
039 return Collections.max(dates);
040 }
041
042 /** Returns the earliest date in a collection of dates */
043 public static Date getEarliest(Collection<Date> dates) {
044 if (dates.isEmpty()) {
045 return null;
046 }
047 return Collections.min(dates);
048 }
049
050 /** Returns the earlier of two dates, or null, if one of the dates is null */
051 public static Date min(Date d1, Date d2) {
052 if (d1 == null || d2 == null) {
053 return null;
054 }
055
056 if (d1.compareTo(d2) < 0) {
057 return d1;
058 }
059 return d2;
060 }
061
062 /** Returns the later of two dates or null, if one of the dates is null. */
063 public static Date max(Date d1, Date d2) {
064 if (d1 == null || d2 == null) {
065 return null;
066 }
067
068 if (d2.compareTo(d1) > 0) {
069 return d2;
070 }
071 return d1;
072 }
073
074 }