code: /* LanguageTool, a natural language style checker 
   * Copyright (C) 2015 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;
  
  import org.apache.lucene.analysis.Analyzer;
  import org.apache.lucene.analysis.standard.StandardAnalyzer;
  import org.apache.lucene.document.Document;
  import org.apache.lucene.document.Field;
  import org.apache.lucene.document.FieldType;
  import org.apache.lucene.index.IndexOptions;
  import org.apache.lucene.index.IndexWriter;
  import org.apache.lucene.index.IndexWriterConfig;
  import org.apache.lucene.store.Directory;
  import org.apache.lucene.store.FSDirectory;
  
  import java.io.File;
  import java.io.IOException;
  
  /**
   * Create an empty Lucene index that only contains a meta document.
   * Useful to fake ngram data if one doesn't have enough disk space.
   */
  final class EmptyLuceneIndexCreator {
  
    private EmptyLuceneIndexCreator() {
    }
  
    public static void main(String[] args) throws IOException {
      if (args.length != 1) {
        System.out.println("Usage: " + EmptyLuceneIndexCreator.class.getSimpleName() + " <indexPath>");
        System.exit(1);
      }
      Analyzer analyzer = new StandardAnalyzer();
      IndexWriterConfig config = new IndexWriterConfig(analyzer);
      Directory directory = FSDirectory.open(new File(args[0]).toPath());
      try (IndexWriter writer = new IndexWriter(directory, config)) {
        FieldType fieldType = new FieldType();
        fieldType.setIndexOptions(IndexOptions.DOCS);
        fieldType.setStored(true);
        Field countField = new Field("totalTokenCount", String.valueOf(0), fieldType);
        Document doc = new Document();
        doc.add(countField);
        writer.addDocument(doc);
      }
    }
  
  }
  