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.activemq.xbean;
018    
019    import java.util.HashMap;
020    
021    import org.apache.activemq.broker.BrokerService;
022    import org.springframework.beans.factory.DisposableBean;
023    import org.springframework.beans.factory.FactoryBean;
024    import org.springframework.beans.factory.InitializingBean;
025    import org.springframework.core.io.Resource;
026    
027    /**
028     * Used to share a single broker even if you have multiple broker bean
029     * definitions. A use case is where you have multiple web applications that want
030     * to start an embedded broker but only the first one to deploy should actually
031     * start it.
032     * 
033     * @version $Revision$
034     */
035    public class PooledBrokerFactoryBean implements FactoryBean, InitializingBean, DisposableBean {
036    
037        static final HashMap<String, SharedBroker> SHARED_BROKER_MAP = new HashMap<String, SharedBroker>();
038    
039        private boolean start;
040        private Resource config;
041    
042        static class SharedBroker {
043            BrokerFactoryBean factory;
044            int refCount;
045        }
046    
047        public void afterPropertiesSet() throws Exception {
048            synchronized (SHARED_BROKER_MAP) {
049                SharedBroker sharedBroker = SHARED_BROKER_MAP.get(config.getFilename());
050                if (sharedBroker == null) {
051                    sharedBroker = new SharedBroker();
052                    sharedBroker.factory = new BrokerFactoryBean();
053                    sharedBroker.factory.setConfig(config);
054                    sharedBroker.factory.setStart(start);
055                    sharedBroker.factory.afterPropertiesSet();
056                    SHARED_BROKER_MAP.put(config.getFilename(), sharedBroker);
057                }
058                sharedBroker.refCount++;
059            }
060        }
061    
062        public void destroy() throws Exception {
063            synchronized (SHARED_BROKER_MAP) {
064                SharedBroker sharedBroker = SHARED_BROKER_MAP.get(config.getFilename());
065                if (sharedBroker != null) {
066                    sharedBroker.refCount--;
067                    if (sharedBroker.refCount == 0) {
068                        sharedBroker.factory.destroy();
069                        SHARED_BROKER_MAP.remove(config.getFilename());
070                    }
071                }
072            }
073        }
074    
075        public Resource getConfig() {
076            return config;
077        }
078    
079        public Object getObject() throws Exception {
080            synchronized (SHARED_BROKER_MAP) {
081                SharedBroker sharedBroker = SHARED_BROKER_MAP.get(config.getFilename());
082                if (sharedBroker != null) {
083                    return sharedBroker.factory.getObject();
084                }
085            }
086            return null;
087        }
088    
089        public Class getObjectType() {
090            return BrokerService.class;
091        }
092    
093        public boolean isSingleton() {
094            return true;
095        }
096    
097        public boolean isStart() {
098            return start;
099        }
100    
101        public void setConfig(Resource config) {
102            this.config = config;
103        }
104    
105        public void setStart(boolean start) {
106            this.start = start;
107        }
108    
109    }