Java Map Sort sortByKey(T map, final boolean descending)

Description

sort By Key

License

Open Source License

Declaration

public static <K extends Comparable<? super K>, V, T extends Map<K, V>> T sortByKey(T map,
            final boolean descending) 

Method Source Code

//package com.java2s;
//License from project: Open Source License 

import java.util.Collections;
import java.util.Comparator;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

public class Main {
    public static <K extends Comparable<? super K>, V, T extends Map<K, V>> T sortByKey(T map) {
        return sortByKey(map, false);
    }//from   w  w  w.  j av a2  s . c om

    public static <K extends Comparable<? super K>, V, T extends Map<K, V>> T sortByKey(T map,
            final boolean descending) {
        return sort(map, new Comparator<Map.Entry<K, V>>() {
            @Override
            public int compare(Map.Entry<K, V> o1, Map.Entry<K, V> o2) {
                return ((o1.getKey()).compareTo(o2.getKey()) * (descending ? -1 : 1));
            }
        });
    }

    public static <K, V, T extends Map<K, V>> T sort(T map, Comparator<Map.Entry<K, V>> c) {
        List<Map.Entry<K, V>> list = new LinkedList<>(map.entrySet());
        Collections.sort(list, c);
        Object result = new LinkedHashMap<>();
        for (Map.Entry<K, V> entry : list) {
            ((T) result).put(entry.getKey(), entry.getValue());
        }
        return (T) result;
    }
}

Related

1. sortByComparatorDecreasing(Map unsortMap)
2. sortByComparatorDouble( final Map map)
3. sortByDescendingValues(Map unsortMap)
4. sortByKey(final Map map, String order)
5. sortByKey(Map map)
6. sortByKeys( Map map)
7. sortByKeys(Map map)
8. sortByMap(List> lists)
9. sortByMap(Map map, int size)