001/* 002 * Copyright (C) 2007 The Guava Authors 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package com.google.common.collect; 018 019import com.google.common.annotations.GwtCompatible; 020 021import java.util.concurrent.ConcurrentMap; 022 023/** 024 * A concurrent map which forwards all its method calls to another concurrent 025 * map. Subclasses should override one or more methods to modify the behavior of 026 * the backing map as desired per the <a 027 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>. 028 * 029 * @author Charles Fry 030 * @since 2.0 (imported from Google Collections Library) 031 */ 032@GwtCompatible 033public abstract class ForwardingConcurrentMap<K, V> extends ForwardingMap<K, V> 034 implements ConcurrentMap<K, V> { 035 036 /** Constructor for use by subclasses. */ 037 protected ForwardingConcurrentMap() {} 038 039 @Override protected abstract ConcurrentMap<K, V> delegate(); 040 041 @Override 042 public V putIfAbsent(K key, V value) { 043 return delegate().putIfAbsent(key, value); 044 } 045 046 @Override 047 public boolean remove(Object key, Object value) { 048 return delegate().remove(key, value); 049 } 050 051 @Override 052 public V replace(K key, V value) { 053 return delegate().replace(key, value); 054 } 055 056 @Override 057 public boolean replace(K key, V oldValue, V newValue) { 058 return delegate().replace(key, oldValue, newValue); 059 } 060 061}