code: private LinkDatabase makeLinkDatabase(Properties props) {
      String dbtype = get(props, "duke.linkdbtype");
      if (dbtype.equals("jdbc"))
        return makeJDBCLinkDatabase(props);
      else if (dbtype.equals("jndi"))
        return makeJNDILinkDatabase(props);
      else
        throw new DukeConfigException("Unknown link database type '" + dbtype +
                                      "'");
    }
docs: --- Create link database