001 /* 002 * Copyright (C) 2010 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.collect; 018 019 import com.google.common.annotations.Beta; 020 021 import java.util.concurrent.Executor; 022 023 import javax.annotation.Nullable; 024 025 /** 026 * A collection of common eviction listeners. 027 * 028 * @author Charles Fry 029 * @since 7 030 */ 031 @Beta 032 public final class EvictionListeners { 033 034 private EvictionListeners() {} 035 036 /** 037 * Returns an asynchronous {@code MapEvictionListener} which processes all 038 * eviction notifications asynchronously, using {@code executor}. 039 * 040 * @param listener the backing listener 041 * @param executor the executor with which eviciton notifications are 042 * asynchronously executed 043 */ 044 public static <K, V> MapEvictionListener<K, V> asynchronous( 045 final MapEvictionListener<K, V> listener, final Executor executor) { 046 return new MapEvictionListener<K, V>() { 047 @Override 048 public void onEviction(@Nullable final K key, @Nullable final V value) { 049 executor.execute(new Runnable() { 050 @Override 051 public void run() { 052 listener.onEviction(key, value); 053 } 054 }); 055 } 056 }; 057 } 058 059 }