001/*
002 * Units of Measurement Common Library for Java
003 * Copyright (c) 2005-2023, Werner Keil and others.
004 *
005 * All rights reserved.
006 *
007 * Redistribution and use in source and binary forms, with or without modification,
008 * are permitted provided that the following conditions are met:
009 *
010 * 1. Redistributions of source code must retain the above copyright notice,
011 *    this list of conditions and the following disclaimer.
012 *
013 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions
014 *    and the following disclaimer in the documentation and/or other materials provided with the distribution.
015 *
016 * 3. Neither the name of JSR-385, Indriya nor the names of their contributors may be used to endorse or promote products
017 *    derived from this software without specific prior written permission.
018 *
019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
020 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
021 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
022 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
023 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
026 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
028 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package tech.uom.lib.common.util;
031
032import java.util.Comparator;
033import javax.measure.Unit;
034
035/**
036 * Comparator to sort units by natural order, looking at both the name and symbol.
037 *
038 * @author <a href="mailto:werner@uom.technology">Werner Keil</a>
039 * @version 1.2
040 * @param <U> the type to compare
041 * @return <b>Given:</b>
042 *         <p>
043 *         Quantity&lt;Time&gt; day = timeFactory.create(1, Units.DAY);
044 *         </p>
045 *         <p>
046 *         Quantity&lt;Time&gt; hours = timeFactory.create(18, Units.HOUR);
047 *         </p>
048 *         <p>
049 *         Quantity&lt;Time&gt; minutes = timeFactory.create(15, Units.HOUR);
050 *         </p>
051 *         <p>
052 *         Quantity&lt;Time&gt; seconds = timeFactory.create(100, Units.HOUR);
053 *         </p>
054 *         will return: seconds, minutes, hours, day
055 * @since 2.0
056 */
057public class UnitComparator<U extends Unit<?>> implements Comparator<U> {
058
059    @Override
060    public int compare(U u1, U u2) {
061        if (u1.getName() != null && u1.getName().equals(u2.getName())) {
062            return u1.toString().compareTo(u2.toString());
063            // TODO why is this the same as below?
064        }
065        return u1.toString().compareTo(u2.toString());
066    }
067}