001package org.apache.commons.jcs.engine; 002 003/* 004 * Licensed to the Apache Software Foundation (ASF) under one 005 * or more contributor license agreements. See the NOTICE file 006 * distributed with this work for additional information 007 * regarding copyright ownership. The ASF licenses this file 008 * to you under the Apache License, Version 2.0 (the 009 * "License"); you may not use this file except in compliance 010 * with the License. You may obtain a copy of the License at 011 * 012 * http://www.apache.org/licenses/LICENSE-2.0 013 * 014 * Unless required by applicable law or agreed to in writing, 015 * software distributed under the License is distributed on an 016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 017 * KIND, either express or implied. See the License for the 018 * specific language governing permissions and limitations 019 * under the License. 020 */ 021 022import java.util.Iterator; 023import java.util.Map; 024import java.util.concurrent.ConcurrentHashMap; 025import java.util.concurrent.ConcurrentMap; 026 027import org.apache.commons.jcs.engine.behavior.ICache; 028import org.apache.commons.jcs.engine.behavior.ICacheEventQueue; 029 030/** 031 * Used to associates a set of [cache listener to cache event queue] for a 032 * cache. 033 */ 034public class CacheListeners<K, V> 035{ 036 /** The cache using the queue. */ 037 public final ICache<K, V> cache; 038 039 /** Map ICacheListener to ICacheEventQueue */ 040 public final ConcurrentMap<Long, ICacheEventQueue<K, V>> eventQMap = 041 new ConcurrentHashMap<Long, ICacheEventQueue<K, V>>(); 042 043 /** 044 * Constructs with the given cache. 045 * <p> 046 * @param cache 047 */ 048 public CacheListeners( ICache<K, V> cache ) 049 { 050 if ( cache == null ) 051 { 052 throw new IllegalArgumentException( "cache must not be null" ); 053 } 054 this.cache = cache; 055 } 056 057 /** @return info on the listeners */ 058 @Override 059 public String toString() 060 { 061 StringBuilder buffer = new StringBuilder(); 062 buffer.append( "\n CacheListeners" ); 063 if ( cache != null ) 064 { 065 buffer.append( "\n Region = " + cache.getCacheName() ); 066 } 067 if ( eventQMap != null ) 068 { 069 buffer.append( "\n Event Queue Map " ); 070 buffer.append( "\n size = " + eventQMap.size() ); 071 Iterator<Map.Entry<Long, ICacheEventQueue<K, V>>> it = eventQMap.entrySet().iterator(); 072 while ( it.hasNext() ) 073 { 074 buffer.append( "\n Entry: " + it.next() ); 075 } 076 } 077 else 078 { 079 buffer.append( "\n No Listeners. " ); 080 } 081 return buffer.toString(); 082 } 083}