1/*
2 * Copyright (C) 2008 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.google.common.collect;
18
19import com.google.common.annotations.GwtCompatible;
20import com.google.common.annotations.GwtIncompatible;
21
22import java.io.Serializable;
23import java.util.Map.Entry;
24
25import javax.annotation.Nullable;
26
27/**
28 * {@code entrySet()} implementation for {@link ImmutableMap}.
29 *
30 * @author Jesse Wilson
31 * @author Kevin Bourrillion
32 */
33@GwtCompatible(emulated = true)
34abstract class ImmutableMapEntrySet<K, V> extends ImmutableSet<Entry<K, V>> {
35  ImmutableMapEntrySet() {}
36
37  abstract ImmutableMap<K, V> map();
38
39  @Override
40  public int size() {
41    return map().size();
42  }
43
44  @Override
45  public boolean contains(@Nullable Object object) {
46    if (object instanceof Entry) {
47      Entry<?, ?> entry = (Entry<?, ?>) object;
48      V value = map().get(entry.getKey());
49      return value != null && value.equals(entry.getValue());
50    }
51    return false;
52  }
53
54  @Override
55  boolean isPartialView() {
56    return map().isPartialView();
57  }
58
59  @GwtIncompatible("serialization")
60  @Override
61  Object writeReplace() {
62    return new EntrySetSerializedForm<K, V>(map());
63  }
64
65  @GwtIncompatible("serialization")
66  private static class EntrySetSerializedForm<K, V> implements Serializable {
67    final ImmutableMap<K, V> map;
68    EntrySetSerializedForm(ImmutableMap<K, V> map) {
69      this.map = map;
70    }
71    Object readResolve() {
72      return map.entrySet();
73    }
74    private static final long serialVersionUID = 0;
75  }
76}
77