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.component.atom;
018    
019    import java.io.IOException;
020    import java.util.Date;
021    import java.util.List;
022    
023    import org.apache.abdera.model.Document;
024    import org.apache.abdera.model.Entry;
025    import org.apache.abdera.model.Feed;
026    import org.apache.abdera.parser.ParseException;
027    import org.apache.camel.Exchange;
028    import org.apache.camel.Processor;
029    
030    /**
031     * Consumer to poll atom feeds and return each entry from the feed step by step.
032     *
033     * @version $Revision: 656976 $
034     */
035    public class AtomEntryPollingConsumer extends AtomPollingConsumer {
036        private Document<Feed> document;
037        private int entryIndex;
038        private EntryFilter entryFilter;
039        private List<Entry> list;
040    
041        public AtomEntryPollingConsumer(AtomEndpoint endpoint, Processor processor, boolean filter,
042                                        Date lastUpdate) {
043            super(endpoint, processor);
044            if (filter) {
045                entryFilter = new UpdatedDateFilter(lastUpdate);
046            }
047        }
048    
049        public void poll() throws Exception {
050            getDocument();
051            Feed feed = document.getRoot();
052    
053            while (hasNextEntry()) {
054                Entry entry = list.get(entryIndex--);
055    
056                boolean valid = true;
057                if (entryFilter != null) {
058                    valid = entryFilter.isValidEntry(endpoint, document, entry);
059                }
060                if (valid) {
061                    Exchange exchange = endpoint.createExchange(feed, entry);
062                    getProcessor().process(exchange);
063                    // return and wait for the next poll to continue from last time (this consumer is stateful)
064                    return;
065                }
066            }
067    
068            // reset document to be able to poll again
069            document = null;
070        }
071    
072        private Document<Feed> getDocument() throws IOException, ParseException {
073            if (document == null) {
074                document = AtomUtils.parseDocument(endpoint.getAtomUri());
075                list = document.getRoot().getEntries();
076                entryIndex = list.size() - 1;
077            }
078            return document;
079        }
080    
081        private boolean hasNextEntry() {
082            return entryIndex >= 0;
083        }
084    
085    }