1 /*
2 * Copyright (C) 2010 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
17 package com.google.common.collect;
18
19 import com.google.common.annotations.GwtCompatible;
20 import com.google.errorprone.annotations.CanIgnoreReturnValue;
21 import java.util.List;
22 import org.checkerframework.checker.nullness.qual.Nullable;
23
24 /**
25 * A list multimap which forwards all its method calls to another list multimap. Subclasses should
26 * override one or more methods to modify the behavior of the backing multimap as desired per the <a
27 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
28 *
29 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code
30 * default} methods. Instead, it inherits their default implementations. When those implementations
31 * invoke methods, they invoke methods on the {@code ForwardingListMultimap}.
32 *
33 * @author Kurt Alfred Kluever
34 * @since 3.0
35 */
36 @GwtCompatible
37 public abstract class ForwardingListMultimap<K, V> extends ForwardingMultimap<K, V>
38 implements ListMultimap<K, V> {
39
40 /** Constructor for use by subclasses. */
41 protected ForwardingListMultimap() {}
42
43 @Override
44 protected abstract ListMultimap<K, V> delegate();
45
46 @Override
47 public List<V> get(@Nullable K key) {
48 return delegate().get(key);
49 }
50
51 @CanIgnoreReturnValue
52 @Override
53 public List<V> removeAll(@Nullable Object key) {
54 return delegate().removeAll(key);
55 }
56
57 @CanIgnoreReturnValue
58 @Override
59 public List<V> replaceValues(K key, Iterable<? extends V> values) {
60 return delegate().replaceValues(key, values);
61 }
62 }