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 }