/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.nutch.indexer;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.nutch.plugin.Extension;
import org.apache.nutch.plugin.ExtensionPoint;
import org.apache.nutch.plugin.PluginRepository;
import org.apache.nutch.plugin.PluginRuntimeException;
import org.apache.nutch.storage.WebPage;
import org.apache.nutch.util.ObjectCache;
/** Creates and caches {@link IndexingFilter} implementing plugins.*/
public class IndexingFilters {
public static final String INDEXINGFILTER_ORDER = "indexingfilterhbase.order";
public final static Logger LOG = LoggerFactory.getLogger(IndexingFilters.class);
private IndexingFilter[] indexingFilters;
public IndexingFilters(Configuration conf) {
/* Get indexingfilter.order property */
String order = conf.get(INDEXINGFILTER_ORDER);
ObjectCache objectCache = ObjectCache.get(conf);
this.indexingFilters = (IndexingFilter[]) objectCache
.getObject(IndexingFilter.class.getName());
if (this.indexingFilters == null) {
/*
* If ordered filters are required, prepare array of filters based on
* property
*/
String[] orderedFilters = null;
if (order != null && !order.trim().equals("")) {
orderedFilters = order.split("\\s+");
}
try {
ExtensionPoint point = PluginRepository.get(conf).getExtensionPoint(
IndexingFilter.X_POINT_ID);
if (point == null)
throw new RuntimeException(IndexingFilter.X_POINT_ID + " not found.");
Extension[] extensions = point.getExtensions();
HashMap<String, IndexingFilter> filterMap =
new HashMap<String, IndexingFilter>();
for (int i = 0; i < extensions.length; i++) {
Extension extension = extensions[i];
IndexingFilter filter = (IndexingFilter) extension
.getExtensionInstance();
LOG.info("Adding " + filter.getClass().getName());
if (!filterMap.containsKey(filter.getClass().getName())) {
filterMap.put(filter.getClass().getName(), filter);
}
}
/*
* If no ordered filters required, just get the filters in an
* indeterminate order
*/
if (orderedFilters == null) {
objectCache.setObject(IndexingFilter.class.getName(),
filterMap.values().toArray(
new IndexingFilter[0]));
/* Otherwise run the filters in the required order */
} else {
ArrayList<IndexingFilter> filters = new ArrayList<IndexingFilter>();
for (int i = 0; i < orderedFilters.length; i++) {
IndexingFilter filter = filterMap.get(orderedFilters[i]);
if (filter != null) {
filters.add(filter);
}
}
objectCache.setObject(IndexingFilter.class.getName(), filters
.toArray(new IndexingFilter[filters.size()]));
}
} catch (PluginRuntimeException e) {
throw new RuntimeException(e);
}
this.indexingFilters = (IndexingFilter[]) objectCache
.getObject(IndexingFilter.class.getName());
}
}
/** Run all defined filters. */
public NutchDocument filter(NutchDocument doc, String url, WebPage page)
throws IndexingException {
for (IndexingFilter indexingFilter : indexingFilters) {
doc = indexingFilter.filter(doc, url, page);
// break the loop if an indexing filter discards the doc
if (doc == null) return null;
}
return doc;
}
public Collection<WebPage.Field> getFields() {
Collection<WebPage.Field> columns = new HashSet<WebPage.Field>();
for (IndexingFilter indexingFilter : indexingFilters) {
Collection<WebPage.Field> fields = indexingFilter.getFields();
if (fields != null) {
columns.addAll(fields);
}
}
return columns;
}
}