exec.csharp.utils.MapSorter.java Source code

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Here is the source code for exec.csharp.utils.MapSorter.java

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/*
 * Copyright 2014 Technische Universitt Darmstadt
 * 
 * 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 exec.csharp.utils;

import java.util.Comparator;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;

import com.google.common.collect.Maps;

public class MapSorter {
    public static <K extends Comparable<K>> Map<K, Integer> sortByCount(Map<K, Integer> map) {

        return sortCustom(map, new Comparator<K>() {
            @Override
            public int compare(K a, K b) {
                Integer ca = map.get(a);
                Integer cb = map.get(b);

                int ia = ca == null ? 0 : ca;
                int ib = cb == null ? 0 : cb;

                if (ia == ib) {
                    return a.compareTo(b);
                }
                return ib - ia;
            }
        });
    }

    public static <K extends Comparable<K>, V extends Comparable<V>> Map<K, V> sort(Map<K, V> map) {

        return sortCustom(map, new Comparator<K>() {
            @Override
            public int compare(K a, K b) {
                V v1 = map.get(a);
                V v2 = map.get(b);

                int res = v1.compareTo(v2);
                if (res == 0) {
                    return b.compareTo(a);
                }
                return res;
            }
        });
    }

    public static <K extends Comparable<K>, V> Map<K, V> sortCustom(Map<K, V> map, Comparator<K> comparator) {

        Set<K> sortedKeys = new TreeSet<K>(comparator);

        sortedKeys.addAll(map.keySet());

        Map<K, V> sortedMap = Maps.newLinkedHashMap();
        for (K key : sortedKeys) {
            sortedMap.put(key, map.get(key));
        }

        return sortedMap;
    }
}