001 /*
002 * Copyright (C) 2011 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
017 package com.google.common.cache;
018
019 import com.google.common.annotations.Beta;
020
021 import java.util.concurrent.Executor;
022
023 /**
024 * A collection of common removal listeners.
025 *
026 * @author Charles Fry
027 * @since 10.0
028 */
029 @Beta
030 public final class RemovalListeners {
031
032 private RemovalListeners() {}
033
034 /**
035 * Returns a {@code RemovalListener} which processes all eviction
036 * notifications using {@code executor}.
037 *
038 * @param listener the backing listener
039 * @param executor the executor with which removal notifications are
040 * asynchronously executed
041 */
042 public static <K, V> RemovalListener<K, V> asynchronous(
043 final RemovalListener<K, V> listener, final Executor executor) {
044 return new RemovalListener<K, V>() {
045 @Override
046 public void onRemoval(final RemovalNotification<K, V> notification) {
047 executor.execute(new Runnable() {
048 @Override
049 public void run() {
050 listener.onRemoval(notification);
051 }
052 });
053 }
054 };
055 }
056
057 }