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 org.apache.camel.Exchange;
020    import org.apache.camel.util.ObjectHelper;
021    
022    /**
023     * An {@link org.apache.camel.processor.aggregate.AggregationStrategy} which just uses the original exchange
024     * which can be needed when you want to preserve the original Exchange. For example when splitting an {@link Exchange}
025     * and then you may want to keep routing using the original {@link Exchange}.
026     *
027     * @see org.apache.camel.processor.Splitter
028     * @version 
029     */
030    public class UseOriginalAggregationStrategy implements AggregationStrategy {
031    
032        private final Exchange original;
033        private final boolean propagateException;
034    
035        public UseOriginalAggregationStrategy(Exchange original, boolean propagateException) {
036            ObjectHelper.notNull(original, "Original Exchange");
037            this.original = original;
038            this.propagateException = propagateException;
039        }
040    
041        public Exchange aggregate(Exchange oldExchange, Exchange newExchange) {
042            if (propagateException) {
043                Exception exception = checkException(oldExchange, newExchange);
044                if (exception != null) {
045                    original.setException(exception);
046                }
047            }
048            return original;
049        }
050    
051        protected Exception checkException(Exchange oldExchange, Exchange newExchange) {
052            if (oldExchange == null) {
053                return newExchange.getException();
054            } else {
055                return (newExchange != null && newExchange.getException() != null)
056                    ? newExchange.getException()
057                    : oldExchange.getException();
058            }
059        }
060    
061        @Override
062        public String toString() {
063            return "UseOriginalAggregationStrategy";
064        }
065    }