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 com.google.common.base.Predicate;
import com.google.common.collect.Collections2;
import java.util.*;

public class Main {
    /**
     * @param col to filter using Collections2.filter
     * @param predicate to use
     * @param fallbackPredicate to use if predicate resulted in empty collection
     * @param <T> type contained in the collection
     * @return the filtered collection
     */
    public static <T> Collection<T> filter(Collection<T> col, Predicate<? super T> predicate,
            Predicate<? super T> fallbackPredicate) {
        Collection<T> result = Collections2.filter(col, predicate);
        if (result.isEmpty()) {
            return Collections2.filter(col, fallbackPredicate);
        }
        return result;
    }

    /**
     * @param original function, result of which to filter
     * @param filter to apply to function results
     * @param <E>
     * @param <T>
     * @param <C>
     * @return a function that wraps the given original function in a function that filters the result of it with
     * given filter
     */
    public static <E, T, C extends List<T>> Function<E, List<T>> filter(final Function<E, C> original,
            final Predicate<T> filter) {
        return new Function<E, List<T>>() {
            public List<T> apply(E input) {
                return new ArrayList<T>(Collections2.filter(original.apply(input), filter));
            }
        };
    }
}