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.aggregate;
018    
019    import java.util.List;
020    
021    import org.apache.camel.Exchange;
022    
023    /**
024     * Aggregate all exchanges into a single combined Exchange holding all the aggregated exchanges
025     * in a {@link java.util.List<Exchange>} as the message body.
026     *
027     * @version 
028     */
029    public class GroupedExchangeAggregationStrategy extends AbstractListAggregationStrategy<Exchange> {
030    
031        @Override
032        @SuppressWarnings("unchecked")
033        public void onCompletion(Exchange exchange) {
034            if (isStoreAsBodyOnCompletion()) {
035                // lets be backwards compatible
036                // TODO: Remove this method in Camel 3.0
037                List list = (List) exchange.getProperty(Exchange.GROUPED_EXCHANGE);
038                if (list != null) {
039                    exchange.getIn().setBody(list);
040                }
041            }
042        }
043    
044        @Override
045        public Exchange aggregate(Exchange oldExchange, Exchange newExchange) {
046            Exchange answer = super.aggregate(oldExchange, newExchange);
047            if (oldExchange == null) {
048                // for the first time we must do a copy as the answer, so the outgoing
049                // exchange is not one of the grouped exchanges, as that causes a endless circular reference
050                answer = answer.copy();
051            }
052            return answer;
053        }
054    
055        @Override
056        public Exchange getValue(Exchange exchange) {
057            return exchange;
058        }
059    
060    }
061