/** * Returns the cached recent messages history. * * @return * @throws IOException */ private History getHistory() throws IOException { synchronized (historyID) { HistoryService historyService = MessageHistoryActivator.getMessageHistoryService().getHistoryService(); if (history == null) { history = historyService.createHistory(historyID, recordStructure); // lets check the version if not our version, re-create // history (delete it) HistoryReader reader = history.getReader(); boolean delete = false; QueryResultSet<HistoryRecord> res = reader.findLast(1); if (res != null && res.hasNext()) { HistoryRecord hr = res.next(); if (hr.getPropertyValues().length >= 4) { if (!hr.getPropertyValues()[3].equals(RECENT_MSGS_VER)) delete = true; } else delete = true; } if (delete) { // delete it try { historyService.purgeLocallyStoredHistory(historyID); history = historyService.createHistory(historyID, recordStructure); } catch (IOException ex) { logger.error("Cannot delete recent_messages history", ex); } } } return history; } }