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;
018    
019    import org.apache.activemq.broker.region.policy.SimpleDispatchSelector;
020    import org.apache.activemq.command.ActiveMQDestination;
021    import org.slf4j.Logger;
022    import org.slf4j.LoggerFactory;
023    
024    /**
025     * Queue dispatch policy that determines if a message can be sent to a subscription
026     * 
027     * @org.apache.xbean.XBean
028     * 
029     */
030    public class QueueDispatchSelector extends SimpleDispatchSelector {
031        private static final Logger LOG = LoggerFactory.getLogger(QueueDispatchSelector.class);
032        private Subscription exclusiveConsumer;
033       
034       
035        /**
036         * @param destination
037         */
038        public QueueDispatchSelector(ActiveMQDestination destination) {
039            super(destination);
040        }
041        
042        public Subscription getExclusiveConsumer() {
043            return exclusiveConsumer;
044        }
045        public void setExclusiveConsumer(Subscription exclusiveConsumer) {
046            this.exclusiveConsumer = exclusiveConsumer;
047        }
048        
049        public boolean isExclusiveConsumer(Subscription s) {
050            return s == this.exclusiveConsumer;
051        }
052        
053           
054        public boolean canSelect(Subscription subscription,
055                MessageReference m) throws Exception {
056           
057            boolean result =  super.canDispatch(subscription, m);
058            if (result && !subscription.isBrowser()) {
059                result = exclusiveConsumer == null || exclusiveConsumer == subscription;
060            }
061            return result;
062        }
063        
064    }