| /* |
| * 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.naivebayes; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| import org.w3c.dom.DocumentFragment; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.FileSystem; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.util.StringUtils; |
| import org.apache.nutch.parse.HTMLMetaTags; |
| import org.apache.nutch.parse.HtmlParseFilter; |
| import org.apache.nutch.parse.Outlink; |
| import org.apache.nutch.parse.Parse; |
| import org.apache.nutch.parse.ParseResult; |
| import org.apache.nutch.protocol.Content; |
| |
| import java.lang.invoke.MethodHandles; |
| import java.io.Reader; |
| import java.io.BufferedReader; |
| import java.io.IOException; |
| import java.util.ArrayList; |
| |
| /** |
| * Html Parse filter that classifies the outlinks from the parseresult as |
| * relevant or irrelevant based on the parseText's relevancy (using a training |
| * file where you can give positive and negative example texts see the |
| * description of parsefilter.naivebayes.trainfile) and if found irrelevant it |
| * gives the link a second chance if it contains any of the words from the list |
| * given in parsefilter.naivebayes.wordlist. CAUTION: Set the parser.timeout to |
| * -1 or a bigger value than 30, when using this classifier. |
| */ |
| public class NaiveBayesParseFilter implements HtmlParseFilter { |
| |
| private static final Logger LOG = LoggerFactory |
| .getLogger(MethodHandles.lookup().lookupClass()); |
| |
| public static final String TRAINFILE_MODELFILTER = "parsefilter.naivebayes.trainfile"; |
| public static final String DICTFILE_MODELFILTER = "parsefilter.naivebayes.wordlist"; |
| |
| private Configuration conf; |
| private String inputFilePath; |
| private String dictionaryFile; |
| private ArrayList<String> wordlist = new ArrayList<String>(); |
| |
| public boolean filterParse(String text) { |
| |
| try { |
| return classify(text); |
| } catch (IOException e) { |
| LOG.error("Error occured while classifying:: " + text + " ::" |
| + StringUtils.stringifyException(e)); |
| } |
| |
| return false; |
| } |
| |
| public boolean filterUrl(String url) { |
| |
| return containsWord(url, wordlist); |
| |
| } |
| |
| public boolean classify(String text) throws IOException { |
| |
| // if classified as relevant "1" then return true |
| if (Classify.classify(text).equals("1")) |
| return true; |
| return false; |
| } |
| |
| public void train() throws Exception { |
| // check if the model file exists, if it does then don't train |
| if (!FileSystem.get(conf).exists(new Path("naivebayes-model"))) { |
| LOG.info("Training the Naive Bayes Model"); |
| Train.start(inputFilePath); |
| } else { |
| LOG.info("Model file already exists. Skipping training."); |
| } |
| } |
| |
| public boolean containsWord(String url, ArrayList<String> wordlist) { |
| for (String word : wordlist) { |
| if (url.contains(word)) { |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| |
| public void setConf(Configuration conf) { |
| this.conf = conf; |
| inputFilePath = conf.get(TRAINFILE_MODELFILTER); |
| dictionaryFile = conf.get(DICTFILE_MODELFILTER); |
| if (inputFilePath == null || inputFilePath.trim().length() == 0 |
| || dictionaryFile == null || dictionaryFile.trim().length() == 0) { |
| String message = "ParseFilter: NaiveBayes: trainfile or wordlist not set in the parsefilte.naivebayes.trainfile or parsefilte.naivebayes.wordlist"; |
| if (LOG.isErrorEnabled()) { |
| LOG.error(message); |
| } |
| throw new IllegalArgumentException(message); |
| } |
| try { |
| if ((FileSystem.get(conf).exists(new Path(inputFilePath))) |
| || (FileSystem.get(conf).exists(new Path(dictionaryFile)))) { |
| String message = "ParseFilter: NaiveBayes: " + inputFilePath + " or " |
| + dictionaryFile + " not found!"; |
| if (LOG.isErrorEnabled()) { |
| LOG.error(message); |
| } |
| throw new IllegalArgumentException(message); |
| } |
| |
| BufferedReader br = null; |
| |
| String CurrentLine; |
| Reader reader = conf.getConfResourceAsReader(dictionaryFile); |
| br = new BufferedReader(reader); |
| while ((CurrentLine = br.readLine()) != null) { |
| wordlist.add(CurrentLine); |
| } |
| |
| } catch (IOException e) { |
| LOG.error(StringUtils.stringifyException(e)); |
| } |
| try { |
| train(); |
| } catch (Exception e) { |
| |
| LOG.error("Error occured while training:: " |
| + StringUtils.stringifyException(e)); |
| |
| } |
| |
| } |
| |
| public Configuration getConf() { |
| return this.conf; |
| } |
| |
| @Override |
| public ParseResult filter(Content content, ParseResult parseResult, |
| HTMLMetaTags metaTags, DocumentFragment doc) { |
| |
| Parse parse = parseResult.get(content.getUrl()); |
| |
| String url = content.getBaseUrl(); |
| ArrayList<Outlink> tempOutlinks = new ArrayList<Outlink>(); |
| String text = parse.getText(); |
| |
| if (!filterParse(text)) { // kick in the second tier |
| // if parent page found |
| // irrelevant |
| LOG.info("ParseFilter: NaiveBayes: Page found irrelevant:: " + url); |
| LOG.info("Checking outlinks"); |
| |
| Outlink[] out = null; |
| for (int i = 0; i < parse.getData().getOutlinks().length; i++) { |
| LOG.info("ParseFilter: NaiveBayes: Outlink to check:: " |
| + parse.getData().getOutlinks()[i].getToUrl()); |
| if (filterUrl(parse.getData().getOutlinks()[i].getToUrl())) { |
| tempOutlinks.add(parse.getData().getOutlinks()[i]); |
| LOG.info("ParseFilter: NaiveBayes: found relevant"); |
| |
| } else { |
| LOG.info("ParseFilter: NaiveBayes: found irrelevant"); |
| } |
| } |
| out = new Outlink[tempOutlinks.size()]; |
| for (int i = 0; i < tempOutlinks.size(); i++) { |
| out[i] = tempOutlinks.get(i); |
| } |
| parse.getData().setOutlinks(out); |
| |
| } else { |
| LOG.info("ParseFilter: NaiveBayes: Page found relevant:: " + url); |
| } |
| |
| return parseResult; |
| } |
| |
| } |