if (arMap == null) {
            arMap = new HashMap<>();
            sessionMap.put(sessionId, arMap);
        }
        return arMap;
    }

    public synchronized void deleteAccessResultMap(final String sessionId) {
        sessionMap.remove(sessionId);
    }

    public synchronized void deleteAllAccessResultMap() {
        sessionMap.clear();
    }

    /*
     * (non-Javadoc)
     *
     * @see org.codelibs.fess.crawler.service.DataService#delete(java.lang.String)
     */
    @Override
    public void delete(final String sessionId) {
        dataHelper.deleteAccessResultMap(sessionId);
    }

    /*
     * (non-Javadoc)
     *
     * @see org.codelibs.fess.crawler.service.DataService#deleteAll()
     */
    @Override
    public void deleteAll() {