/**
* 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.analysis.lang;
// Nutch imports
import java.nio.ByteBuffer;
import java.util.Collection;
import java.util.HashSet;
import org.apache.avro.util.Utf8;
import org.apache.hadoop.conf.Configuration;
import org.apache.nutch.indexer.IndexingException;
import org.apache.nutch.indexer.IndexingFilter;
import org.apache.nutch.indexer.NutchDocument;
import org.apache.nutch.metadata.Metadata;
import org.apache.nutch.storage.WebPage;
import org.apache.nutch.storage.WebPage.Field;
import org.apache.nutch.util.Bytes;
/**
* An {@link org.apache.nutch.indexer.IndexingFilter} that adds a
* <code>lang</code> (language) field to the document.
*
* It tries to find the language of the document by checking
* if {@link HTMLLanguageParser} has added some language
* information
*
* @author Sami Siren
* @author Jerome Charron
*/
public class LanguageIndexingFilter implements IndexingFilter {
private Configuration conf;
private static final Collection<WebPage.Field> FIELDS = new HashSet<WebPage.Field>();
static {
FIELDS.add(WebPage.Field.METADATA);
}
/**
* Constructs a new Language Indexing Filter.
*/
public LanguageIndexingFilter() {}
public NutchDocument filter(NutchDocument doc, String url, WebPage page)
throws IndexingException {
// check if LANGUAGE found, possibly put there by HTMLLanguageParser
String lang = null;
ByteBuffer blang = page.getFromMetadata(new Utf8(Metadata.LANGUAGE));
if (blang != null) {
lang = Bytes.toString(blang.array());
}
if (lang == null || lang.length() == 0) {
lang = "unknown";
}
doc.add("lang", lang);
return doc;
}
public Collection<Field> getFields() {
return FIELDS;
}
public void addIndexBackendOptions(Configuration conf) {
}
public void setConf(Configuration conf) {
this.conf = conf;
}
public Configuration getConf() {
return this.conf;
}
}