001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.camel.component.cache;
018    
019    import net.sf.ehcache.CacheManager;
020    import org.apache.camel.impl.ServiceSupport;
021    
022    public abstract class CacheManagerFactory extends ServiceSupport {
023        private CacheManager cacheManager;
024    
025        public synchronized CacheManager getInstance() {
026            if (cacheManager == null) {
027                cacheManager = createCacheManagerInstance();
028            }
029            
030            return cacheManager;
031        }
032    
033        /**
034         * Creates {@link CacheManager}.
035         * <p/>
036         * The default implementation is {@link DefaultCacheManagerFactory}.
037         *
038         * @return {@link CacheManager}
039         */
040        protected abstract CacheManager createCacheManagerInstance();
041    
042        @Override
043        protected void doStart() throws Exception {
044        }
045    
046        @Override
047        protected void doStop() throws Exception {
048            // shutdown cache manager when stopping
049            if (cacheManager != null) {
050                cacheManager.shutdown();
051            }
052        }
053    }