mapSorter

package fr.edu.grenoble.sconet.common.util;

import java.util.LinkedHashMap;
import java.util.Map;

import lombok.AccessLevel;
import lombok.AllArgsConstructor;
import lombok.EqualsAndHashCode;
import lombok.Getter;
import lombok.NoArgsConstructor;

@NoArgsConstructor(access = AccessLevel.NONE)
public final class MapUtils {

    public static <A extends Comparable<A>, B extends Comparable<B>> Map<A, B> trierMap(
            final Map<A, B> mapATrier) {
        @AllArgsConstructor
        @EqualsAndHashCode(of = {"a", "b"})
        @Getter
        class ComparableMapEntry<C extends A, D extends B>
                implements Comparable<ComparableMapEntry<C, D>> {

            private final C a;

            private final D b;

            public ComparableMapEntry(final Map.Entry<C, D> mapEntry) {
                this(mapEntry.getKey(), mapEntry.getValue());
            }

            @Override
            public int compareTo(final ComparableMapEntry<C, D> o) {
                int compareResult = this.getA().compareTo(o.getA());
                if (compareResult == 0) {
                    return this.getB().compareTo(o.getB());
                }
                return compareResult;
            }
        }

        return mapATrier.entrySet()
            .stream()
            .map(ComparableMapEntry::new)
            .sorted()
            .collect(LinkedHashMap::new, (final Map<A, B> map,
                    final ComparableMapEntry<A, B> entry) -> map.put(entry.getA(), entry.getB()),
                    Map::putAll);
    }

}