Java tutorial
//package com.java2s; /* * Copyright (C) 2009 Emweb bvba, Leuven, Belgium. * * See the LICENSE file for terms of use. */ import java.util.List; import java.util.Map; public class Main { public static <K, V> void findInMultimap(Map<K, List<V>> map, K key, List<V> result) { List<V> tmp = map.get(key); if (tmp != null) result.addAll(tmp); } }