Java tutorial
/* * Copyright 2010 Chad Retz * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy of * the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations under * the License. */ package org.statmantis.util; import java.util.HashMap; import java.util.Map; import java.util.Map.Entry; import org.apache.commons.collections15.Transformer; /** * Extension of {@link org.apache.commons.collections15.MapUtils} * * @author Chad Retz */ public final class MapUtils extends org.apache.commons.collections15.MapUtils { public static <T, U> Entry<T, U> createEntry(final T key, final U value) { return new Entry<T, U>() { private U entryValue = value; @Override public T getKey() { return key; } @Override public U getValue() { return entryValue; } @Override public U setValue(U entryValue) { this.entryValue = entryValue; return entryValue; } }; } public static <T, U, V, W> Map<V, W> transform(Map<T, U> original, Transformer<Entry<T, U>, Entry<V, W>> transformer) { Map<V, W> ret = new HashMap<V, W>(original.size()); //TODO: Fail, can't add to an entry set idiot! ret.entrySet().addAll(CollectionUtils.transform(original.entrySet(), transformer)); return ret; } private MapUtils() { } }