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 org.apache.camel.AsyncProcessor;
020    import org.apache.camel.Consumer;
021    import org.apache.camel.Endpoint;
022    import org.apache.camel.Processor;
023    import org.apache.camel.spi.ExceptionHandler;
024    import org.apache.camel.support.ServiceSupport;
025    import org.apache.camel.util.AsyncProcessorConverterHelper;
026    import org.apache.camel.util.ServiceHelper;
027    import org.apache.camel.util.URISupport;
028    import org.slf4j.Logger;
029    import org.slf4j.LoggerFactory;
030    
031    /**
032     * A default consumer useful for implementation inheritance.
033     *
034     * @version 
035     */
036    public class DefaultConsumer extends ServiceSupport implements Consumer {
037        protected final transient Logger log = LoggerFactory.getLogger(getClass());
038        private final Endpoint endpoint;
039        private final Processor processor;
040        private volatile AsyncProcessor asyncProcessor;
041        private ExceptionHandler exceptionHandler;
042    
043        public DefaultConsumer(Endpoint endpoint, Processor processor) {
044            this.endpoint = endpoint;
045            this.processor = processor;
046        }
047    
048        @Override
049        public String toString() {
050            return "Consumer[" + URISupport.sanitizeUri(endpoint.getEndpointUri()) + "]";
051        }
052    
053        public Endpoint getEndpoint() {
054            return endpoint;
055        }
056    
057        public Processor getProcessor() {
058            return processor;
059        }
060    
061        /**
062         * Provides an {@link org.apache.camel.AsyncProcessor} interface to the configured
063         * processor on the consumer. If the processor does not implement the interface,
064         * it will be adapted so that it does.
065         */
066        public synchronized AsyncProcessor getAsyncProcessor() {
067            if (asyncProcessor == null) {            
068                asyncProcessor = AsyncProcessorConverterHelper.convert(processor);
069            }
070            return asyncProcessor;
071        }
072    
073        public ExceptionHandler getExceptionHandler() {
074            if (exceptionHandler == null) {
075                exceptionHandler = new LoggingExceptionHandler(getClass());
076            }
077            return exceptionHandler;
078        }
079    
080        public void setExceptionHandler(ExceptionHandler exceptionHandler) {
081            this.exceptionHandler = exceptionHandler;
082        }
083    
084        protected void doStop() throws Exception {
085            log.debug("Stopping consumer: {}", this);
086            ServiceHelper.stopServices(processor);
087        }
088    
089        protected void doStart() throws Exception {
090            log.debug("Starting consumer: {}", this);
091            ServiceHelper.startServices(processor);
092        }
093    
094        /**
095         * Handles the given exception using the {@link #getExceptionHandler()}
096         * 
097         * @param t the exception to handle
098         */
099        protected void handleException(Throwable t) {
100            Throwable newt = (t == null) ? new IllegalArgumentException("Handling [null] exception") : t;
101            getExceptionHandler().handleException(newt);
102        }
103    
104        /**
105         * Handles the given exception using the {@link #getExceptionHandler()}
106         *
107         * @param message additional message about the exception
108         * @param t the exception to handle
109         */
110        protected void handleException(String message, Throwable t) {
111            Throwable newt = (t == null) ? new IllegalArgumentException("Handling [null] exception") : t;
112            getExceptionHandler().handleException(message, newt);
113        }
114    }