| /* |
| * 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.parsefilter.regex; |
| |
| import java.lang.invoke.MethodHandles; |
| import java.io.BufferedReader; |
| import java.io.IOException; |
| import java.io.FileReader; |
| import java.io.Reader; |
| import java.io.StringReader; |
| import java.util.HashMap; |
| import java.util.Map; |
| import java.util.regex.Matcher; |
| import java.util.regex.Pattern; |
| |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.nutch.parse.HTMLMetaTags; |
| import org.apache.nutch.parse.Parse; |
| import org.apache.nutch.parse.HtmlParseFilter; |
| import org.apache.nutch.parse.ParseResult; |
| import org.apache.nutch.plugin.Extension; |
| import org.apache.nutch.plugin.PluginRepository; |
| import org.apache.nutch.protocol.Content; |
| |
| import org.apache.commons.lang.StringUtils; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| import org.w3c.dom.DocumentFragment; |
| |
| /** |
| * RegexParseFilter. If a regular expression matches either HTML or |
| * extracted text, a configurable field is set to true. |
| */ |
| public class RegexParseFilter implements HtmlParseFilter { |
| |
| private static final Logger LOG = LoggerFactory |
| .getLogger(MethodHandles.lookup().lookupClass()); |
| private static String attributeFile = null; |
| |
| private Configuration conf; |
| |
| private static final Map<String,RegexRule> rules = new HashMap<>(); |
| |
| public ParseResult filter(Content content, ParseResult parseResult, HTMLMetaTags metaTags, DocumentFragment doc) { |
| Parse parse = parseResult.get(content.getUrl()); |
| String html = new String(content.getContent()); |
| String text = parse.getText(); |
| |
| for (Map.Entry<String, RegexRule> entry : rules.entrySet()) { |
| String field = entry.getKey(); |
| RegexRule regexRule = entry.getValue(); |
| |
| String source = null; |
| if (regexRule.source.equalsIgnoreCase("html")) { |
| source = html; |
| } |
| if (regexRule.source.equalsIgnoreCase("text")) { |
| source = text; |
| } |
| |
| if (source == null) { |
| LOG.error("source for regex rule: " + field + " misconfigured"); |
| } |
| |
| if (matches(source, regexRule.regex)) { |
| parse.getData().getParseMeta().set(field, "true"); |
| } else { |
| parse.getData().getParseMeta().set(field, "false"); |
| } |
| } |
| |
| return parseResult; |
| } |
| |
| public void setConf(Configuration conf) { |
| this.conf = conf; |
| |
| // get the extensions for domain urlfilter |
| String pluginName = "parsefilter-regex"; |
| Extension[] extensions = PluginRepository.get(conf).getExtensionPoint( |
| HtmlParseFilter.class.getName()).getExtensions(); |
| for (int i = 0; i < extensions.length; i++) { |
| Extension extension = extensions[i]; |
| if (extension.getDescriptor().getPluginId().equals(pluginName)) { |
| attributeFile = extension.getAttribute("file"); |
| break; |
| } |
| } |
| |
| // handle blank non empty input |
| if (attributeFile != null && attributeFile.trim().equals("")) { |
| attributeFile = null; |
| } |
| |
| if (attributeFile != null) { |
| if (LOG.isInfoEnabled()) { |
| LOG.info("Attribute \"file\" is defined for plugin " + pluginName |
| + " as " + attributeFile); |
| } |
| } |
| else { |
| if (LOG.isWarnEnabled()) { |
| LOG.warn("Attribute \"file\" is not defined in plugin.xml for plugin " |
| + pluginName); |
| } |
| } |
| |
| String file = conf.get("parsefilter.regex.file", attributeFile); |
| String stringRules = conf.get("parsefilter.regex.rules"); |
| Reader reader = null; |
| if (stringRules != null) { // takes precedence over files |
| reader = new StringReader(stringRules); |
| } else { |
| reader = conf.getConfResourceAsReader(file); |
| } |
| try { |
| if (reader == null) { |
| reader = new FileReader(file); |
| } |
| readConfiguration(reader); |
| } |
| catch (IOException e) { |
| LOG.error(org.apache.hadoop.util.StringUtils.stringifyException(e)); |
| } |
| } |
| |
| public Configuration getConf() { |
| return this.conf; |
| } |
| |
| private boolean matches(String value, Pattern pattern) { |
| if (value != null) { |
| Matcher matcher = pattern.matcher(value); |
| return matcher.find(); |
| } |
| |
| return false; |
| } |
| |
| private synchronized void readConfiguration(Reader configReader) throws IOException { |
| if (rules.size() > 0) { |
| return; |
| } |
| |
| String line; |
| BufferedReader reader = new BufferedReader(configReader); |
| while ((line = reader.readLine()) != null) { |
| if (StringUtils.isNotBlank(line) && !line.startsWith("#")) { |
| line = line.trim(); |
| String[] parts = line.split("\\s"); |
| |
| if (parts.length == 3) { |
| String field = parts[0].trim(); |
| String source = parts[1].trim(); |
| String regex = parts[2].trim(); |
| |
| rules.put(field, new RegexRule(source, regex)); |
| } else { |
| LOG.info("RegexParseFilter rule is invalid. " + line); |
| } |
| } |
| } |
| } |
| |
| private static class RegexRule { |
| public RegexRule(String source, String regex) { |
| this.source = source; |
| this.regex = Pattern.compile(regex); |
| } |
| String source; |
| Pattern regex; |
| } |
| } |