void init() {
        loadProperties();

        String defaultLogLevelString = getStringProperty(SimpleLogger.DEFAULT_LOG_LEVEL_KEY, null);
        if (defaultLogLevelString != null)
            defaultLogLevel = stringToLevel(defaultLogLevelString);

        showLogName = getBooleanProperty(SimpleLogger.SHOW_LOG_NAME_KEY, SimpleLoggerConfiguration.SHOW_LOG_NAME_DEFAULT);
        showShortLogName = getBooleanProperty(SimpleLogger.SHOW_SHORT_LOG_NAME_KEY, SHOW_SHORT_LOG_NAME_DEFAULT);
        showDateTime = getBooleanProperty(SimpleLogger.SHOW_DATE_TIME_KEY, SHOW_DATE_TIME_DEFAULT);
        showThreadName = getBooleanProperty(SimpleLogger.SHOW_THREAD_NAME_KEY, SHOW_THREAD_NAME_DEFAULT);
        showThreadId = getBooleanProperty(SimpleLogger.SHOW_THREAD_ID_KEY, SHOW_THREAD_ID_DEFAULT);
        dateTimeFormatStr = getStringProperty(SimpleLogger.DATE_TIME_FORMAT_KEY, DATE_TIME_FORMAT_STR_DEFAULT);
        levelInBrackets = getBooleanProperty(SimpleLogger.LEVEL_IN_BRACKETS_KEY, LEVEL_IN_BRACKETS_DEFAULT);
        warnLevelString = getStringProperty(SimpleLogger.WARN_LEVEL_STRING_KEY, WARN_LEVELS_STRING_DEFAULT);

        logFile = getStringProperty(SimpleLogger.LOG_FILE_KEY, logFile);

        cacheOutputStream = getBooleanProperty(SimpleLogger.CACHE_OUTPUT_STREAM_STRING_KEY, CACHE_OUTPUT_STREAM_DEFAULT);
        outputChoice = computeOutputChoice(logFile, cacheOutputStream);

        if (dateTimeFormatStr != null) {
            try {
                dateFormatter = new SimpleDateFormat(dateTimeFormatStr);
            } catch (IllegalArgumentException e) {
                Reporter.error("Bad date format in " + CONFIGURATION_FILE + "; will output relative time", e);
            }
        }
    }
See https://jira.qos.ch/browse/SLF4J-499
@since 1.7.33 and 2.0.0-alpha6
slf4j-simple/src/main/java/org/slf4j/simple/SimpleLoggerConfiguration.java