001/* 002 * Copyright (C) 2011 The Guava Authors 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except 005 * in compliance with the License. You may obtain a copy of the License at 006 * 007 * http://www.apache.org/licenses/LICENSE-2.0 008 * 009 * Unless required by applicable law or agreed to in writing, software distributed under the License 010 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express 011 * or implied. See the License for the specific language governing permissions and limitations under 012 * the License. 013 */ 014 015package com.google.common.cache; 016 017import static com.google.common.base.Preconditions.checkNotNull; 018 019import com.google.common.annotations.GwtIncompatible; 020import java.util.concurrent.Executor; 021 022/** 023 * A collection of common removal listeners. 024 * 025 * @author Charles Fry 026 * @since 10.0 027 */ 028@GwtIncompatible 029public final class RemovalListeners { 030 031 private RemovalListeners() {} 032 033 /** 034 * Returns a {@code RemovalListener} which processes all eviction notifications using 035 * {@code executor}. 036 * 037 * @param listener the backing listener 038 * @param executor the executor with which removal notifications are asynchronously executed 039 */ 040 public static <K, V> RemovalListener<K, V> asynchronous( 041 final RemovalListener<K, V> listener, final Executor executor) { 042 checkNotNull(listener); 043 checkNotNull(executor); 044 return new RemovalListener<K, V>() { 045 @Override 046 public void onRemoval(final RemovalNotification<K, V> notification) { 047 executor.execute( 048 new Runnable() { 049 @Override 050 public void run() { 051 listener.onRemoval(notification); 052 } 053 }); 054 } 055 }; 056 } 057}