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 java.io.IOException;
020    import java.util.List;
021    
022    import javax.jms.JMSException;
023    
024    import org.apache.activemq.broker.region.group.MessageGroupMap;
025    import org.apache.activemq.broker.region.policy.SimpleDispatchSelector;
026    import org.apache.activemq.command.ActiveMQDestination;
027    import org.apache.activemq.command.ActiveMQMessage;
028    import org.apache.activemq.command.ConsumerId;
029    import org.apache.activemq.command.Message;
030    import org.slf4j.Logger;
031    import org.slf4j.LoggerFactory;
032    
033    /**
034     * Queue dispatch policy that determines if a message can be sent to a subscription
035     * 
036     * @org.apache.xbean.XBean
037     * 
038     */
039    public class QueueDispatchSelector extends SimpleDispatchSelector {
040        private static final Logger LOG = LoggerFactory.getLogger(QueueDispatchSelector.class);
041        private Subscription exclusiveConsumer;
042       
043       
044        /**
045         * @param destination
046         */
047        public QueueDispatchSelector(ActiveMQDestination destination) {
048            super(destination);
049        }
050        
051        public Subscription getExclusiveConsumer() {
052            return exclusiveConsumer;
053        }
054        public void setExclusiveConsumer(Subscription exclusiveConsumer) {
055            this.exclusiveConsumer = exclusiveConsumer;
056        }
057        
058        public boolean isExclusiveConsumer(Subscription s) {
059            return s == this.exclusiveConsumer;
060        }
061        
062           
063        public boolean canSelect(Subscription subscription,
064                MessageReference m) throws Exception {
065           
066            boolean result =  super.canDispatch(subscription, m);
067            if (result && !subscription.isBrowser()) {
068                result = exclusiveConsumer == null || exclusiveConsumer == subscription;
069            }
070            return result;
071        }
072        
073    }