code: public static JournalWriter getInstance(Map<String, String> parameters,
                                              String role,
                                              ServerInterface server)
              throws JournalException {
          Object journalWriter =
                  JournalHelper
                          .createInstanceAccordingToParameter(PARAMETER_JOURNAL_WRITER_CLASSNAME,
                                                              new Class[] {
                                                                      Map.class,
                                                                      String.class,
                                                                      ServerInterface.class},
                                                              new Object[] {
                                                                      parameters,
                                                                      role,
                                                                      server},
                                                              parameters);
          logger.info("JournalWriter is " + journalWriter.toString());
          return (JournalWriter) journalWriter;
      }
docs: Create an instance of the proper JournalWriter child class, as determined
  by the server parameters.