index a document

IndexWriter writer = new IndexWriter(directory, new StandardAnalyzer());
Document doc = new Document();
doc.add(new TextField("title", "The Great Gatsby", Field.Store.YES));
doc.add(new TextField("author", "F. Scott Fitzgerald", Field.Store.YES));
doc.add(new TextField("content", "In my younger and more vulnerable years...", Field.Store.NO));
writer.addDocument(doc);
writer.close();