| /* |
| * Copyright (C) 2007 The Guava Authors |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.google.common.collect; |
| |
| import com.google.common.annotations.GwtCompatible; |
| import com.google.errorprone.annotations.CanIgnoreReturnValue; |
| import java.util.concurrent.ConcurrentMap; |
| |
| /** |
| * A concurrent map which forwards all its method calls to another concurrent map. Subclasses should |
| * override one or more methods to modify the behavior of the backing map as desired per the <a |
| * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>. |
| * |
| * <p><b>{@code default} method warning:</b> This class forwards calls to <i>only some</i> {@code |
| * default} methods. Specifically, it forwards calls only for methods that existed <a |
| * href="https://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ConcurrentMap.html">before |
| * {@code default} methods were introduced</a>. For newer methods, like {@code forEach}, it inherits |
| * their default implementations. When those implementations invoke methods, they invoke methods on |
| * the {@code ForwardingConcurrentMap}. |
| * |
| * @author Charles Fry |
| * @since 2.0 |
| */ |
| @GwtCompatible |
| public abstract class ForwardingConcurrentMap<K, V> extends ForwardingMap<K, V> |
| implements ConcurrentMap<K, V> { |
| |
| /** Constructor for use by subclasses. */ |
| protected ForwardingConcurrentMap() {} |
| |
| @Override |
| protected abstract ConcurrentMap<K, V> delegate(); |
| |
| @CanIgnoreReturnValue |
| @Override |
| public V putIfAbsent(K key, V value) { |
| return delegate().putIfAbsent(key, value); |
| } |
| |
| @CanIgnoreReturnValue |
| @Override |
| public boolean remove(Object key, Object value) { |
| return delegate().remove(key, value); |
| } |
| |
| @CanIgnoreReturnValue |
| @Override |
| public V replace(K key, V value) { |
| return delegate().replace(key, value); |
| } |
| |
| @CanIgnoreReturnValue |
| @Override |
| public boolean replace(K key, V oldValue, V newValue) { |
| return delegate().replace(key, oldValue, newValue); |
| } |
| } |