code: private static void indexFile(IndexWriter writer, File f)
          throws IOException {
  
      if (f.isHidden() || !f.exists() || !f.canRead()) {
          System.err.println("Could not write "+f.getName());
          return;
      }
  
      System.err.println("Indexing " + f.getCanonicalPath());
  
      Document doc = new Document();
  
      doc.add(new Field("path", f.getCanonicalPath(), Field.Store.YES, Field.Index.NOT_ANALYZED));
      doc.add(new Field("modified",DateTools.timeToString(f.lastModified(), DateTools.Resolution.MINUTE),Field.Store.YES, Field.Index.NOT_ANALYZED));
      doc.add(new Field("contents", new FileReader(f)));
                  
      writer.addDocument(doc);
     }
docs: method to actually index a file using Lucene, adds a document
  onto the index writer