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.idempotent;
018    
019    import org.apache.camel.Exchange;
020    import org.apache.camel.spi.IdempotentRepository;
021    import org.apache.camel.spi.Synchronization;
022    import org.apache.camel.util.ExchangeHelper;
023    import org.apache.commons.logging.Log;
024    import org.apache.commons.logging.LogFactory;
025    
026    /**
027     * On completion strategy for {@link org.apache.camel.processor.idempotent.IdempotentConsumer}.
028     * <p/>
029     * This strategy adds the message id to the idempotent repository in cast the exchange
030     * was processed successfully. In case of failure the message id is <b>not</b> added.
031     *
032     * @version $Revision: 784697 $
033     */
034    public class IdempotentOnCompletion implements Synchronization {
035        private static final transient Log LOG = LogFactory.getLog(IdempotentOnCompletion.class);
036        private final IdempotentRepository idempotentRepository;
037        private final String messageId;
038        private final boolean eager;
039    
040        public IdempotentOnCompletion(IdempotentRepository idempotentRepository, String messageId, boolean eager) {
041            this.idempotentRepository = idempotentRepository;
042            this.messageId = messageId;
043            this.eager = eager;
044        }
045    
046        public void onComplete(Exchange exchange) {
047            if (ExchangeHelper.isFailureHandled(exchange)) {
048                // the exchange did not process successfully but was failure handled by the dead letter channel
049                // and thus moved to the dead letter queue. We should thus not consider it as complete.
050                onFailedMessage(exchange, messageId);
051            } else {
052                onCompletedMessage(exchange, messageId);
053            }
054        }
055    
056        public void onFailure(Exchange exchange) {
057            onFailedMessage(exchange, messageId);
058        }
059    
060        /**
061         * A strategy method to allow derived classes to overload the behavior of
062         * processing a completed message
063         *
064         * @param exchange the exchange
065         * @param messageId the message ID of this exchange
066         */
067        @SuppressWarnings("unchecked")
068        protected void onCompletedMessage(Exchange exchange, String messageId) {
069            if (!eager) {
070                // if not eager we should add the key when its complete
071                idempotentRepository.add(messageId);
072            }
073            idempotentRepository.confirm(messageId);
074        }
075    
076        /**
077         * A strategy method to allow derived classes to overload the behavior of
078         * processing a failed message
079         *
080         * @param exchange the exchange
081         * @param messageId the message ID of this exchange
082         */
083        @SuppressWarnings("unchecked")
084        protected void onFailedMessage(Exchange exchange, String messageId) {
085            idempotentRepository.remove(messageId);
086            if (LOG.isDebugEnabled()) {
087                LOG.debug("Removed from repository as exchange failed: " + exchange + " with id: " + messageId);
088            }
089        }
090    
091        @Override
092        public String toString() {
093            return "IdempotentOnCompletion[" + messageId + ']';
094        }
095    
096    }