MapUtil2.java

/*
 * Copyright 2014 Alex Bennett & Alexander Chauncey
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.demigodsrpg.util.misc;

import com.google.common.collect.Lists;

import java.util.*;

public class MapUtil2 {
    /**
     * Sort a Map from smallest to largest, or in <code>reverse</code>.
     *
     * @param map     The Map object to be sorted.
     * @param reverse Reverse the ordering.
     * @return A sorted version of <code>map</code>.
     */
    public static <K, V extends Comparable<? super V>> Map<K, V> sortByValue(Map<K, V> map, boolean reverse) {
        List<Map.Entry<K, V>> list = new LinkedList<Map.Entry<K, V>>(map.entrySet());
        Collections.sort(list, new Comparator<Map.Entry<K, V>>() {
            public int compare(Map.Entry<K, V> o1, Map.Entry<K, V> o2) {
                return (o1.getValue()).compareTo(o2.getValue());
            }
        });

        if (reverse) list = Lists.reverse(list);

        Map<K, V> result = new LinkedHashMap<K, V>();
        for (Map.Entry<K, V> entry : list)
            result.put(entry.getKey(), entry.getValue());
        return result;
    }
}