| /* |
| * 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.parse.metatags; |
| |
| import java.lang.invoke.MethodHandles; |
| import java.util.Enumeration; |
| import java.util.HashSet; |
| import java.util.Locale; |
| import java.util.Properties; |
| import java.util.Set; |
| |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.nutch.metadata.Metadata; |
| import org.apache.nutch.parse.HTMLMetaTags; |
| import org.apache.nutch.parse.HtmlParseFilter; |
| import org.apache.nutch.parse.Parse; |
| import org.apache.nutch.parse.ParseResult; |
| import org.apache.nutch.protocol.Content; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| import org.w3c.dom.DocumentFragment; |
| |
| /** |
| * Parse HTML meta tags (keywords, description) and store them in the parse |
| * metadata so that they can be indexed with the index-metadata plugin with the |
| * prefix 'metatag.'. Metatags are matched ignoring case. |
| */ |
| public class MetaTagsParser implements HtmlParseFilter { |
| |
| private static final Logger LOG = LoggerFactory |
| .getLogger(MethodHandles.lookup().lookupClass()); |
| |
| private Configuration conf; |
| |
| private Set<String> metatagset = new HashSet<String>(); |
| |
| @Override |
| public void setConf(Configuration conf) { |
| this.conf = conf; |
| // specify whether we want a specific subset of metadata |
| // by default take everything we can find |
| String[] values = conf.getStrings("metatags.names", "*"); |
| for (String val : values) { |
| metatagset.add(val.toLowerCase(Locale.ROOT)); |
| } |
| } |
| |
| @Override |
| public Configuration getConf() { |
| return this.conf; |
| } |
| |
| /** |
| * Check whether the metatag is in the list of metatags to be indexed (or if |
| * '*' is specified). If yes, add it to parse metadata. |
| */ |
| private void addIndexedMetatags(Metadata metadata, String metatag, |
| String value) { |
| String lcMetatag = metatag.toLowerCase(Locale.ROOT); |
| if (metatagset.contains("*") || metatagset.contains(lcMetatag)) { |
| if (LOG.isDebugEnabled()) { |
| LOG.debug("Found meta tag: {}\t{}", lcMetatag, value); |
| } |
| metadata.add("metatag." + lcMetatag, value); |
| } |
| } |
| |
| /** |
| * Check whether the metatag is in the list of metatags to be indexed (or if |
| * '*' is specified). If yes, add it with all values to parse metadata. |
| */ |
| private void addIndexedMetatags(Metadata metadata, String metatag, |
| String[] values) { |
| String lcMetatag = metatag.toLowerCase(Locale.ROOT); |
| if (metatagset.contains("*") || metatagset.contains(lcMetatag)) { |
| String key = "metatag." + lcMetatag; |
| for (String value : values) { |
| if (LOG.isDebugEnabled()) { |
| LOG.debug("Found meta tag: {}\t{}", lcMetatag, value); |
| } |
| metadata.add(key, value); |
| } |
| } |
| } |
| |
| @Override |
| public ParseResult filter(Content content, ParseResult parseResult, |
| HTMLMetaTags metaTags, DocumentFragment doc) { |
| |
| Parse parse = parseResult.get(content.getUrl()); |
| Metadata metadata = parse.getData().getParseMeta(); |
| |
| /* |
| * NUTCH-1559: do not extract meta values from ParseData's metadata to avoid |
| * duplicate metatag values |
| */ |
| |
| Metadata generalMetaTags = metaTags.getGeneralTags(); |
| for (String tagName : generalMetaTags.names()) { |
| addIndexedMetatags(metadata, tagName, generalMetaTags.getValues(tagName)); |
| } |
| |
| Properties httpequiv = metaTags.getHttpEquivTags(); |
| for (Enumeration<?> tagNames = httpequiv.propertyNames(); tagNames |
| .hasMoreElements();) { |
| String name = (String) tagNames.nextElement(); |
| String value = httpequiv.getProperty(name); |
| addIndexedMetatags(metadata, name, value); |
| } |
| |
| return parseResult; |
| } |
| |
| } |