Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
/**
 * Copyright (C) 2012-2015 52North Initiative for Geospatial Open Source
 * Software GmbH
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation.
 *
 * If the program is linked with libraries which are licensed under one of
 * the following licenses, the combination of the program with the linked
 * library is not considered a "derivative work" of the program:
 *
 *     - Apache License, version 2.0
 *     - Apache Software License, version 1.0
 *     - GNU Lesser General Public License, version 3
 *     - Mozilla Public License, versions 1.0, 1.1 and 2.0
 *     - Common Development and Distribution License (CDDL), version 1.0
 *
 * Therefore the distribution of the program linked with libraries licensed
 * under the aforementioned licenses, is permitted by the copyright holders
 * if the distribution is compliant with both the GNU General Public
 * License version 2 and the aforementioned licenses.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
 * Public License for more details.
 */

import static java.util.Comparator.comparing;

import static java.util.stream.Collectors.toMap;

import java.util.LinkedHashMap;

import java.util.Map;
import java.util.Map.Entry;

import java.util.function.BinaryOperator;
import java.util.stream.Collector;

public class Main {
    public static <K, V extends Comparable<? super V>> Map<K, V> sortByValue(Map<K, V> map) {
        return map.entrySet().stream().sorted(comparing(Map.Entry::getValue)).collect(toLinkedHashMap());
    }

    private static <K, V> Collector<Entry<K, V>, ?, LinkedHashMap<K, V>> toLinkedHashMap() {
        return toMap(Entry::getKey, Entry::getValue, throwingMerger(), LinkedHashMap::new);
    }

    private static <T> BinaryOperator<T> throwingMerger() {
        return (u, v) -> {
            throw new IllegalStateException(String.format("Duplicate key %s", u));
        };
    }
}