Index a MySQL database with Apache Lucene, and keep them synchronized
public static void main(String[] args) throws Exception {

    Class.forName("com.mysql.jdbc.Driver").newInstance();
    Connection connection = DriverManager.getConnection("jdbc:mysql://localhost/mydb", "root", "");
    StandardAnalyzer analyzer = new StandardAnalyzer(Version.LUCENE_36);
    IndexWriterConfig config = new IndexWriterConfig(Version.LUCENE_36, analyzer);
    IndexWriter writer = new IndexWriter(FSDirectory.open(INDEX_DIR), config);

    String query = "SELECT id, name FROM tag";
    Statement statement = connection.createStatement();
    ResultSet result = statement.executeQuery(query);

    while (result.next()) {
        Document document = new Document();
        document.add(new Field("id", result.getString("id"), Field.Store.YES, Field.Index.NOT_ANALYZED));
        document.add(new Field("name", result.getString("name"), Field.Store.NO, Field.Index.ANALYZED));
        writer.updateDocument(new Term("id", result.getString("id")), document);
    }

    writer.close();

}

writer.deleteAll();
while (result.next()) {
    Document document = new Document();
    document.add(new Field("id", result.getString("id"), Field.Store.YES, Field.Index.NOT_ANALYZED));
    document.add(new Field("name", result.getString("name"), Field.Store.NO, Field.Index.ANALYZED));
    writer.addDocument(document);
}