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.broker.region.virtual;
018    
019    import org.apache.activemq.broker.ProducerBrokerExchange;
020    import org.apache.activemq.broker.region.Destination;
021    import org.apache.activemq.broker.region.DestinationFilter;
022    import org.apache.activemq.command.ActiveMQDestination;
023    import org.apache.activemq.command.ActiveMQQueue;
024    import org.apache.activemq.command.Message;
025    import org.apache.activemq.util.LRUCache;
026    
027    /**
028     * A Destination which implements <a
029     * href="http://activemq.org/site/virtual-destinations.html">Virtual Topic</a>
030     * 
031     * 
032     */
033    public class VirtualTopicInterceptor extends DestinationFilter {
034    
035        private String prefix;
036        private String postfix;
037        private boolean local;
038        private LRUCache<ActiveMQDestination,ActiveMQQueue> cache = new LRUCache<ActiveMQDestination,ActiveMQQueue>();
039    
040        public VirtualTopicInterceptor(Destination next, String prefix, String postfix, boolean local) {
041            super(next);
042            this.prefix = prefix;
043            this.postfix = postfix;
044            this.local = local;
045        }
046    
047        public void send(ProducerBrokerExchange context, Message message) throws Exception {
048            if (!message.isAdvisory() && !(local && message.getBrokerPath() != null)) {
049                ActiveMQDestination queueConsumers = getQueueConsumersWildcard(message.getDestination());
050                send(context, message, queueConsumers);
051            }
052            super.send(context, message);
053        }
054    
055        protected ActiveMQDestination getQueueConsumersWildcard(ActiveMQDestination original) {
056            ActiveMQQueue queue;
057            synchronized(cache){
058                queue = cache.get(original);
059                if (queue==null){
060                    queue = new ActiveMQQueue(prefix + original.getPhysicalName() + postfix);
061                    cache.put(original,queue);
062                }
063            }
064            return queue;
065        }
066    }