| package org.apache.commons.ognl.internal; |
| |
| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| |
| /* |
| * $Id$ |
| */ |
| import org.apache.commons.ognl.internal.entry.CacheEntryFactory; |
| |
| import java.util.concurrent.ConcurrentHashMap; |
| |
| public class ConcurrentHashMapCache<K, V> |
| implements Cache<K, V> |
| { |
| private ConcurrentHashMap<K, V> cache = new ConcurrentHashMap<K, V>(); |
| |
| private CacheEntryFactory<K, V> cacheEntryFactory; |
| |
| public ConcurrentHashMapCache() |
| { |
| } |
| |
| public ConcurrentHashMapCache( CacheEntryFactory<K, V> cacheEntryFactory ) |
| { |
| this.cacheEntryFactory = cacheEntryFactory; |
| } |
| |
| public void clear() |
| { |
| cache.clear(); |
| } |
| |
| public int getSize() |
| { |
| return cache.size(); |
| } |
| |
| public V get( K key ) |
| throws CacheException |
| { |
| V v = cache.get( key ); |
| if ( shouldCreate( cacheEntryFactory, v ) ) |
| { |
| return put( key, cacheEntryFactory.create( key ) ); |
| } |
| return v; |
| } |
| |
| protected boolean shouldCreate( CacheEntryFactory<K, V> cacheEntryFactory, V v ) |
| throws CacheException |
| { |
| return cacheEntryFactory != null && v == null; |
| } |
| |
| public V put( K key, V value ) |
| { |
| V collision = cache.putIfAbsent( key, value ); |
| if ( collision != null ) |
| { |
| return collision; |
| } |
| return value; |
| } |
| |
| public boolean contains( K key ) |
| { |
| return this.cache.contains( key ); |
| } |
| } |