1 package org.apache.lucene.util;
4 * Licensed to the Apache Software Foundation (ASF) under one or more
5 * contributor license agreements. See the NOTICE file distributed with
6 * this work for additional information regarding copyright ownership.
7 * The ASF licenses this file to You under the Apache License, Version 2.0
8 * (the "License"); you may not use this file except in compliance with
9 * the License. You may obtain a copy of the License at
11 * http://www.apache.org/licenses/LICENSE-2.0
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
22 import java.util.Collection;
23 import java.util.HashSet;
27 * Helper class for keeping Lists of Objects associated with keys. <b>WARNING: THIS CLASS IS NOT THREAD SAFE</b>
30 public class MapOfSets<K, V> {
32 private final Map<K, Set<V>> theMap;
35 * @param m the backing store for this object
37 public MapOfSets(Map<K, Set<V>> m) {
42 * @return direct access to the map backing this object.
44 public Map<K, Set<V>> getMap() {
49 * Adds val to the Set associated with key in the Map. If key is not
50 * already in the map, a new Set will first be created.
51 * @return the size of the Set associated with key once val is added to it.
53 public int put(K key, V val) {
55 if (theMap.containsKey(key)) {
56 theSet = theMap.get(key);
58 theSet = new HashSet<V>(23);
59 theMap.put(key, theSet);
65 * Adds multiple vals to the Set associated with key in the Map.
67 * already in the map, a new Set will first be created.
68 * @return the size of the Set associated with key once val is added to it.
70 public int putAll(K key, Collection<? extends V> vals) {
72 if (theMap.containsKey(key)) {
73 theSet = theMap.get(key);
75 theSet = new HashSet<V>(23);
76 theMap.put(key, theSet);