code: /* LanguageTool, a natural language style checker
   * Copyright (C) 2014 Daniel Naber (http://www.danielnaber.de)
   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301
   * USA
   */
  package org.languagetool.dev.dumpcheck;
  
  import java.io.*;
  
  import org.apache.commons.compress.compressors.CompressorException;
  import org.apache.commons.compress.compressors.CompressorStreamFactory;
  import org.languagetool.Language;
  import org.languagetool.Languages;
  
  import java.io.BufferedInputStream;
  import java.io.FileInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  
  /**
   * Command line tool to extract sentences from a (optionally bz2-compressed) Wikipedia XML dump.
   * @since 2.6
   */
  class WikipediaSentenceExtractor {
  
    private void extract(Language language, String xmlDumpPath, String outputFile) throws IOException, CompressorException {
      try (FileInputStream fis = new FileInputStream(xmlDumpPath);
           BufferedInputStream bis = new BufferedInputStream(fis);
           FileWriter fw = new FileWriter(outputFile)) {
        InputStream input;
        if (xmlDumpPath.endsWith(".bz2")) {
          input = new CompressorStreamFactory().createCompressorInputStream(bis);
        } else if (xmlDumpPath.endsWith(".xml")) {
          input = bis;
        } else {
          throw new IllegalArgumentException("Unknown file name, expected '.xml' or '.bz2': " + xmlDumpPath);
        }
        int sentenceCount = 0;
        WikipediaSentenceSource source = new WikipediaSentenceSource(input, language);
        while (source.hasNext()) {
          String sentence = source.next().getText();
          if (skipSentence(sentence)) {
            continue;
          }
          //System.out.println(sentence);
          fw.write(sentence);
          fw.write('\n');
          sentenceCount++;
          if (sentenceCount % 1000 == 0) {
            System.err.println("Exporting sentence #" + sentenceCount + "...");
          }
        }
      }
    }
  
    private boolean skipSentence(String sentence) {
      return sentence.trim().length() == 0 || Character.isLowerCase(sentence.trim().charAt(0));
    }
  
    public static void main(String[] args) throws IOException, CompressorException {
      if (args.length != 3) {
        System.out.println("Usage: " + WikipediaSentenceExtractor.class.getSimpleName() + " <langCode> <wikipediaXmlDump> <output>");
        System.exit(1);
      }
      WikipediaSentenceExtractor extractor = new WikipediaSentenceExtractor();
      extractor.extract(Languages.getLanguageForShortCode(args[0]), args[1], args[2]);
    }
  }
  