Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
/*
 * Copyright (c) 2013 The Finnish National Board of Education - Opetushallitus
 *
 * This program is free software: Licensed under the EUPL, Version 1.1 or - as
 * soon as they will be approved by the European Commission - subsequent versions
 * of the EUPL (the "Licence");
 *
 * You may not use this work except in compliance with the Licence.
 * You may obtain a copy of the Licence at: http://www.osor.eu/eupl/
 *
 * 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
 * European Union Public Licence for more details.
 */

import com.google.common.base.Function;

import java.util.*;

public class Main {
    /**
     * @param collection to collect extracted values from
     * @param extractor to transform items of collection to collections to combine
     * @param <E> the original container type
     * @param <T> the extracted item type
     * @return the extracted items in a single list
     */
    public static <E, T, C extends Collection<T>> List<T> collect(Collection<E> collection,
            Function<E, C> extractor) {
        List<T> results = new ArrayList<T>();
        for (E item : collection) {
            results.addAll(extractor.apply(item));
        }
        return results;
    }

    /**
     * @param map to collect
     * @param keys to collect from map
     * @param to add each values for given keys from given map
     * @param <K> key type
     * @param <T> value type
     * @param <C> collectin type to collect result to
     * @return the provided to collection with given keys from map appended
     */
    public static <K, T, C extends Collection<? super T>> C collect(Map<K, T> map, Collection<K> keys, C to) {
        for (K key : keys) {
            to.add(map.get(key));
        }
        return to;
    }
}