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.processor;
018    
019    import org.apache.camel.Exchange;
020    import org.apache.camel.Predicate;
021    import org.apache.camel.Processor;
022    import org.apache.camel.util.ServiceHelper;
023    import org.apache.commons.logging.Log;
024    import org.apache.commons.logging.LogFactory;
025    
026    /**
027     * The processor which implements the
028     * <a href="http://camel.apache.org/message-filter.html">Message Filter</a> EIP pattern.
029     *
030     * @version $Revision: 890339 $
031     */
032    public class FilterProcessor extends DelegateProcessor implements Traceable {
033        private static final Log LOG = LogFactory.getLog(FilterProcessor.class);
034        private final Predicate predicate;
035    
036        public FilterProcessor(Predicate predicate, Processor processor) {
037            super(processor);
038            this.predicate = predicate;
039        }
040    
041        public void process(Exchange exchange) throws Exception {
042            boolean matches = predicate.matches(exchange);
043    
044            if (LOG.isDebugEnabled()) {
045                LOG.debug("Filter matches: " + matches + " for exchange: " + exchange);
046            }
047    
048            if (matches) {
049                super.process(exchange);
050            }
051        }
052    
053        @Override
054        public String toString() {
055            return "Filter[if: " + predicate + " do: " + getProcessor() + "]";
056        }
057    
058        public String getTraceLabel() {
059            return "filter[if: " + predicate + "]";
060        }
061    
062        public Predicate getPredicate() {
063            return predicate;
064        }
065    
066        @Override
067        protected void doStart() throws Exception {
068            super.doStart();
069            ServiceHelper.startService(predicate);
070        }
071    
072        @Override
073        protected void doStop() throws Exception {
074            ServiceHelper.stopService(predicate);
075            super.doStop();
076        }
077    }