+++ /dev/null
-/*
- * jFCPlib - Filters.java - Copyright © 2009 David Roden
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * 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.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- */
-package net.pterodactylus.util.filter;
-
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Map;
-import java.util.NoSuchElementException;
-import java.util.Set;
-import java.util.Map.Entry;
-
-/**
- * Defines various methods to filter {@link Collection}s.
- *
- * @author David ‘Bombe’ Roden <bombe@freenetproject.org>
- */
-public class Filters {
-
- /**
- * Returns a list that contains only the elements from the given list that
- * match the given filter.
- *
- * @param <E>
- * The type of the list elements
- * @param list
- * The list to filter
- * @param listFilter
- * The list filter
- * @return The filtered list
- */
- public static <E> List<E> filteredList(List<E> list, Filter<E> listFilter) {
- List<E> filteredList = new ArrayList<E>();
- for (E element : list) {
- if (listFilter.filterObject(element)) {
- filteredList.add(element);
- }
- }
- return filteredList;
- }
-
- /**
- * Returns a set that contains only the elements from the given set that
- * match the given filter.
- *
- * @param <E>
- * The type of the set elements
- * @param set
- * The set to filter
- * @param setFilter
- * The set filter
- * @return The filtered set
- */
- public static <E> Set<E> filteredSet(Set<E> set, Filter<E> setFilter) {
- Set<E> filteredSet = new HashSet<E>();
- for (E element : set) {
- if (setFilter.filterObject(element)) {
- filteredSet.add(element);
- }
- }
- return filteredSet;
- }
-
- /**
- * Returns a map that contains only the elements from the given map that
- * match the given filter.
- *
- * @param <K>
- * The type of the map keys
- * @param <V>
- * The type of the map values
- * @param map
- * The map to filter
- * @param mapFilter
- * The map filter
- * @return The filtered map
- */
- public static <K, V> Map<K, V> filteredMap(Map<K, V> map, Filter<Entry<K, V>> mapFilter) {
- Map<K, V> filteredMap = new HashMap<K, V>();
- for (Entry<K, V> element : map.entrySet()) {
- if (mapFilter.filterObject(element)) {
- filteredMap.put(element.getKey(), element.getValue());
- }
- }
- return filteredMap;
- }
-
- /**
- * Returns a collection that contains only the elements from the given
- * collection that match the given filter.
- *
- * @param <K>
- * The type of the collection values
- * @param collection
- * The collection to filter
- * @param collectionFilter
- * The collection filter
- * @return The filtered collection
- */
- public static <K> Collection<K> filteredCollection(Collection<K> collection, Filter<K> collectionFilter) {
- return filteredList(new ArrayList<K>(collection), collectionFilter);
- }
-
- /**
- * Returns an iterator that contains only the elements from the given
- * iterator that match the given filter.
- *
- * @param <E>
- * The type of the iterator elements
- * @param iterator
- * The iterator to filter
- * @param iteratorFilter
- * The iterator filter
- * @return The filtered iterator
- */
- public static <E> Iterator<E> filteredIterator(final Iterator<E> iterator, final Filter<E> iteratorFilter) {
- return new Iterator<E>() {
-
- private boolean gotNextElement = false;
-
- private E nextElement;
-
- private void getNextElement() {
- if (gotNextElement) {
- return;
- }
- while (iterator.hasNext()) {
- nextElement = iterator.next();
- if (iteratorFilter.filterObject(nextElement)) {
- gotNextElement = true;
- break;
- }
- }
- }
-
- /**
- * {@inheritDoc}
- *
- * @see java.util.Iterator#hasNext()
- */
- public boolean hasNext() {
- getNextElement();
- return gotNextElement;
- }
-
- /**
- * {@inheritDoc}
- *
- * @see java.util.Iterator#next()
- */
- public E next() {
- getNextElement();
- if (!gotNextElement) {
- throw new NoSuchElementException("no more elements in iteration");
- }
- gotNextElement = false;
- return nextElement;
- }
-
- /**
- * {@inheritDoc}
- *
- * @see java.util.Iterator#remove()
- */
- public void remove() {
- throw new UnsupportedOperationException("remove() not supported on this iteration");
- }
-
- };
- }
-
-}
projects / jFCPlib.git / blobdiff