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.component.seda;
018    
019    import java.util.concurrent.BlockingQueue;
020    import java.util.concurrent.ExecutorService;
021    import java.util.concurrent.Executors;
022    import java.util.concurrent.ThreadFactory;
023    import java.util.concurrent.TimeUnit;
024    
025    import org.apache.camel.AsyncCallback;
026    import org.apache.camel.AsyncProcessor;
027    import org.apache.camel.Consumer;
028    import org.apache.camel.Exchange;
029    import org.apache.camel.Processor;
030    import org.apache.camel.impl.ServiceSupport;
031    import org.apache.camel.impl.converter.AsyncProcessorTypeConverter;
032    import org.apache.commons.logging.Log;
033    import org.apache.commons.logging.LogFactory;
034    
035    /**
036     * A Consumer for the SEDA component.
037     *
038     * @version $Revision: 69602 $
039     */
040    public class SedaConsumer extends ServiceSupport implements Consumer, Runnable {
041        private static final transient Log LOG = LogFactory.getLog(SedaConsumer.class);
042    
043        private SedaEndpoint endpoint;
044        private AsyncProcessor processor;
045        private ExecutorService executor;
046    
047        public SedaConsumer(SedaEndpoint endpoint, Processor processor) {
048            this.endpoint = endpoint;
049            this.processor = AsyncProcessorTypeConverter.convert(processor);
050        }
051    
052        @Override
053        public String toString() {
054            return "SedaConsumer: " + endpoint.getEndpointUri();
055        }
056    
057        public void run() {
058            BlockingQueue<Exchange> queue = endpoint.getQueue();
059            while (queue != null && isRunAllowed()) {
060                final Exchange exchange;
061                try {
062                    exchange = queue.poll(1000, TimeUnit.MILLISECONDS);
063                } catch (InterruptedException e) {
064                    if (LOG.isDebugEnabled()) {
065                        LOG.debug("Interupted: " + e, e);
066                    }
067                    continue;
068                }
069                if (exchange != null) {
070                    if (isRunAllowed()) {
071                        try {
072                            processor.process(exchange, new AsyncCallback() {
073                                public void done(boolean sync) {
074                                }
075                            });
076                        } catch (Exception e) {
077                            LOG.error("Seda queue caught: " + e, e);
078                        }
079                    } else {
080                        LOG.warn("This consumer is stopped during polling an exchange, so putting it back on the seda queue: " + exchange);
081                        try {
082                            queue.put(exchange);
083                        } catch (InterruptedException e) {
084                            if (LOG.isDebugEnabled()) {
085                                LOG.debug("Interupted: " + e, e);
086                            }
087                        }
088                    }
089                }
090            }
091        }
092    
093        protected void doStart() throws Exception {
094            int concurrentConsumers = endpoint.getConcurrentConsumers();
095            executor = Executors.newFixedThreadPool(concurrentConsumers, new ThreadFactory() {
096            
097                public Thread newThread(Runnable runnable) {
098                    Thread thread = new Thread(runnable, getThreadName(endpoint.getEndpointUri()));
099                    thread.setDaemon(true);
100                    return thread;
101                }
102            });
103            for (int i = 0; i < concurrentConsumers; i++) {
104                executor.execute(this);
105            }
106        }
107    
108        protected void doStop() throws Exception {
109            executor.shutdownNow();
110            executor = null;
111        }
112    
113    }