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.AsyncCallback;
020    import org.apache.camel.Exchange;
021    import org.apache.camel.Predicate;
022    import org.apache.camel.Processor;
023    import org.apache.camel.Traceable;
024    import org.apache.camel.util.ServiceHelper;
025    import org.slf4j.Logger;
026    import org.slf4j.LoggerFactory;
027    
028    /**
029     * The processor which implements the
030     * <a href="http://camel.apache.org/message-filter.html">Message Filter</a> EIP pattern.
031     *
032     * @version 
033     */
034    public class FilterProcessor extends DelegateAsyncProcessor implements Traceable {
035        private static final Logger LOG = LoggerFactory.getLogger(FilterProcessor.class);
036        private final Predicate predicate;
037    
038        public FilterProcessor(Predicate predicate, Processor processor) {
039            super(processor);
040            this.predicate = predicate;
041        }
042    
043        @Override
044        public boolean process(Exchange exchange, AsyncCallback callback) {
045            boolean matches = false;
046            try {
047                matches = predicate.matches(exchange);
048            } catch (Throwable e) {
049                exchange.setException(e);
050            }
051    
052            LOG.debug("Filter matches: {} for exchange: {}", matches, exchange);
053    
054            // set property whether the filter matches or not
055            exchange.setProperty(Exchange.FILTER_MATCHED, matches);
056    
057            if (matches) {
058                return super.process(exchange, callback);
059            } else {
060                callback.done(true);
061                return true;
062            }
063        }
064    
065        @Override
066        public String toString() {
067            return "Filter[if: " + predicate + " do: " + getProcessor() + "]";
068        }
069    
070        public String getTraceLabel() {
071            return "filter[if: " + predicate + "]";
072        }
073    
074        public Predicate getPredicate() {
075            return predicate;
076        }
077    
078        @Override
079        protected void doStart() throws Exception {
080            super.doStart();
081            ServiceHelper.startService(predicate);
082        }
083    
084        @Override
085        protected void doStop() throws Exception {
086            ServiceHelper.stopService(predicate);
087            super.doStop();
088        }
089    }