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.camel.impl;
018    
019    import java.util.HashMap;
020    import java.util.Map;
021    
022    import org.apache.camel.Endpoint;
023    import org.apache.camel.Exchange;
024    import org.apache.camel.FailedToCreateConsumerException;
025    import org.apache.camel.IsSingleton;
026    import org.apache.camel.PollingConsumer;
027    import org.apache.camel.util.ServiceHelper;
028    import org.apache.commons.logging.Log;
029    import org.apache.commons.logging.LogFactory;
030    
031    /**
032     * Cache containing created {@link org.apache.camel.Consumer}.
033     *
034     * @version $Revision: 778782 $
035     */
036    public class ConsumerCache extends ServiceSupport {
037        private static final transient Log LOG = LogFactory.getLog(ConsumerCache.class);
038    
039        private final Map<String, PollingConsumer> consumers = new HashMap<String, PollingConsumer>();
040    
041        public synchronized PollingConsumer getConsumer(Endpoint endpoint) {
042            String key = endpoint.getEndpointUri();
043            PollingConsumer answer = consumers.get(key);
044            if (answer == null) {
045                try {
046                    answer = endpoint.createPollingConsumer();
047                    answer.start();
048                } catch (Exception e) {
049                    throw new FailedToCreateConsumerException(endpoint, e);
050                }
051    
052                boolean singleton = true;
053                if (answer instanceof IsSingleton) {
054                    singleton = ((IsSingleton)answer).isSingleton();
055                }
056    
057                if (singleton) {
058                    if (LOG.isDebugEnabled()) {
059                        LOG.debug("Adding to consumer cache with key: " + endpoint + " for consumer: " + answer);
060                    }
061                    consumers.put(key, answer);
062                } else {
063                    if (LOG.isDebugEnabled()) {
064                        LOG.debug("Consumer for endpoint: " + key + " is not singleton and thus not added to producer cache");
065                    }
066                }
067            }
068            return answer;
069        }
070    
071        public Exchange receive(Endpoint endpoint) {
072            if (LOG.isDebugEnabled()) {
073                LOG.debug("<<<< " + endpoint);
074            }
075    
076            PollingConsumer consumer = getConsumer(endpoint);
077            return consumer.receive();
078        }
079    
080        public Exchange receive(Endpoint endpoint, long timeout) {
081            if (LOG.isDebugEnabled()) {
082                LOG.debug("<<<< " + endpoint);
083            }
084    
085            PollingConsumer consumer = getConsumer(endpoint);
086            return consumer.receive(timeout);
087        }
088    
089        public Exchange receiveNoWait(Endpoint endpoint) {
090            if (LOG.isDebugEnabled()) {
091                LOG.debug("<<<< " + endpoint);
092            }
093    
094            PollingConsumer consumer = getConsumer(endpoint);
095            return consumer.receiveNoWait();
096        }
097    
098        protected void doStop() throws Exception {
099            ServiceHelper.stopServices(consumers.values());
100            consumers.clear();
101        }
102    
103        protected void doStart() throws Exception {
104        }
105    
106    }