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;
018    
019    import java.util.Collections;
020    import java.util.HashMap;
021    import java.util.Iterator;
022    import java.util.Map;
023    import org.slf4j.Logger;
024    import org.slf4j.LoggerFactory;
025    
026    /**
027     * 
028     */
029    public class BrokerRegistry {
030    
031        private static final Logger LOG = LoggerFactory.getLogger(BrokerRegistry.class);
032        private static final BrokerRegistry INSTANCE = new BrokerRegistry();
033    
034        private final Object mutex = new Object();
035        private final Map<String, BrokerService> brokers = new HashMap<String, BrokerService>();
036    
037        public static BrokerRegistry getInstance() {
038            return INSTANCE;
039        }
040    
041        /**
042         * @param brokerName
043         * @return the BrokerService
044         */
045        public BrokerService lookup(String brokerName) {
046            BrokerService result = null;
047            synchronized (mutex) {
048                result = brokers.get(brokerName);
049                if (result == null && brokerName != null && brokerName.equals(BrokerService.DEFAULT_BROKER_NAME)) {
050                    result = findFirst();
051                    if (result != null) {
052                        LOG.warn("Broker localhost not started so using " + result.getBrokerName() + " instead");
053                    }
054                }
055            }
056            return result;
057        }
058    
059        /**
060         * Returns the first registered broker found
061         * 
062         * @return the first BrokerService
063         */
064        public BrokerService findFirst() {
065            synchronized (mutex) {
066                Iterator<BrokerService> iter = brokers.values().iterator();
067                while (iter.hasNext()) {
068                    return iter.next();
069                }
070                return null;
071            }
072        }
073    
074        /**
075         * @param brokerName
076         * @param broker
077         */
078        public void bind(String brokerName, BrokerService broker) {
079            synchronized (mutex) {
080                brokers.put(brokerName, broker);
081                mutex.notifyAll();
082            }
083        }
084    
085        /**
086         * @param brokerName
087         */
088        public void unbind(String brokerName) {
089            synchronized (mutex) {
090                brokers.remove(brokerName);
091            }
092        }
093    
094        /**
095         * @return the mutex used
096         */
097        public Object getRegistryMutext() {
098            return mutex;
099        }
100        
101        public Map<String, BrokerService> getBrokers() {
102            return Collections.unmodifiableMap(this.brokers);
103        }
104    }