| /* |
| * 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; |
| |
| import org.apache.nutch.crawl.CrawlDatum; |
| import org.apache.nutch.crawl.Inlinks; |
| import org.apache.nutch.indexer.IndexingFilter; |
| import org.apache.nutch.indexer.IndexingException; |
| import org.apache.nutch.indexer.NutchDocument; |
| import org.apache.hadoop.io.Text; |
| import org.apache.nutch.parse.Parse; |
| import org.apache.nutch.metadata.Metadata; |
| import org.apache.nutch.net.protocols.Response; |
| |
| import java.util.HashSet; |
| import java.util.Set; |
| |
| import org.apache.hadoop.conf.Configuration; |
| |
| /** |
| * An {@link org.apache.nutch.indexer.IndexingFilter} that add a |
| * <code>lang</code> (language) field to the document. |
| * |
| * It tries to find the language of the document by: |
| * <ul> |
| * <li>First, checking if {@link HTMLLanguageParser} add some language |
| * information</li> |
| * <li>Then, checking if a <code>Content-Language</code> HTTP header can be |
| * found</li> |
| * <li>Finaly by analyzing the document content</li> |
| * </ul> |
| * |
| * @author Sami Siren |
| * @author Jerome Charron |
| */ |
| public class LanguageIndexingFilter implements IndexingFilter { |
| |
| private Configuration conf; |
| private Set<String> indexLangs; |
| |
| /** |
| * Constructs a new Language Indexing Filter. |
| */ |
| public LanguageIndexingFilter() { |
| |
| } |
| |
| // Inherited JavaDoc |
| @Override |
| public NutchDocument filter(NutchDocument doc, Parse parse, Text url, |
| CrawlDatum datum, Inlinks inlinks) throws IndexingException { |
| |
| // check if LANGUAGE found, possibly put there by HTMLLanguageParser |
| String lang = parse.getData().getParseMeta().get(Metadata.LANGUAGE); |
| |
| // check if HTTP-header tels us the language |
| if (lang == null) { |
| lang = parse.getData().getContentMeta().get(Response.CONTENT_LANGUAGE); |
| } |
| |
| if (lang == null || lang.length() == 0) { |
| lang = "unknown"; |
| } |
| |
| if (!indexLangs.isEmpty() && !indexLangs.contains(lang)) { |
| return null; |
| } |
| |
| doc.add("lang", lang); |
| |
| return doc; |
| } |
| |
| @Override |
| public void setConf(Configuration conf) { |
| this.conf = conf; |
| indexLangs = new HashSet<>(conf.getStringCollection("lang.index.languages")); |
| } |
| |
| @Override |
| public Configuration getConf() { |
| return this.conf; |
| } |
| |
| } |