001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.camel.util;
018
019import java.util.Comparator;
020
021import org.apache.camel.Ordered;
022
023/**
024 * A comparator to sort {@link Ordered}
025 *
026 * @version 
027 */
028public final class OrderedComparator implements Comparator<Object> {
029
030    private static final OrderedComparator INSTANCE = new OrderedComparator();
031    private static final OrderedComparator INSTANCE_REVERSE = new OrderedComparator(true);
032
033    private final boolean reverse;
034
035    /**
036     * Favor using the static instance {@link #get()}
037     */
038    public OrderedComparator() {
039        this(false);
040    }
041
042    /**
043     * Favor using the static instance {@link #getReverse()}
044     */
045    public OrderedComparator(boolean reverse) {
046        this.reverse = reverse;
047    }
048
049    /**
050     * Gets the comparator that sorts a..z
051     */
052    public static OrderedComparator get() {
053        return INSTANCE;
054    }
055
056    /**
057     * Gets the comparator that sorts z..a (reverse)
058     */
059    public static OrderedComparator getReverse() {
060        return INSTANCE_REVERSE;
061    }
062
063    public int compare(Object o1, Object o2) {
064        Integer num1 = 0;
065        Integer num2 = 0;
066        if (o1 instanceof Ordered) {
067            num1 = ((Ordered) o1).getOrder();
068        }
069        if (o2 instanceof Ordered) {
070            num2 = ((Ordered) o2).getOrder();
071        }
072        int answer = num1.compareTo(num2);
073        return reverse ? -1 * answer : answer;
074    }
075}