Here you can find the source of reverse(Map
Parameter | Description |
---|---|
K | the type of key in the map to reverse. These will be the values in the returned map. |
V | the type of values in the map to revert. These will be the keys in the returned map. |
map | the Map to reverse. |
public static <K, V> Map<V, K> reverse(Map<K, V> map)
//package com.java2s; /**//w w w . j av a 2 s . co m * Copyright (c) 2002-2014 "Neo Technology," * Network Engine for Objects in Lund AB [http://neotechnology.com] * * This file is part of Neo4j. * * Neo4j 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 3 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, see <http://www.gnu.org/licenses/>. */ import java.util.HashMap; import java.util.Map; public class Main { /** * Reversed a map, making the key value and the value key. * @param <K> the type of key in the map to reverse. These will be the * values in the returned map. * @param <V> the type of values in the map to revert. These will be the * keys in the returned map. * @param map the {@link Map} to reverse. * @return the reverse of {@code map}. A new {@link Map} will be returned * where the keys from {@code map} will be the values and the values will * be the keys. */ public static <K, V> Map<V, K> reverse(Map<K, V> map) { Map<V, K> reversedMap = new HashMap<V, K>(); for (Map.Entry<K, V> entry : map.entrySet()) { reversedMap.put(entry.getValue(), entry.getKey()); } return reversedMap; } }