Java tutorial
/* * 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 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>. * * @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(); @Override public V putIfAbsent(K key, V value) { return delegate().putIfAbsent(key, value); } @Override public boolean remove(Object key, Object value) { return delegate().remove(key, value); } @Override public V replace(K key, V value) { return delegate().replace(key, value); } @Override public boolean replace(K key, V oldValue, V newValue) { return delegate().replace(key, oldValue, newValue); } }