public void watch(Class<?> loggerClass, Level level) {
    this.loggerClass = loggerClass;
    Appender appender = new AbstractAppender(APPENDER_NAME, null, PatternLayout.createDefaultLayout()) {
        @Override
        public void append(LogEvent event) {
            logEvents.add(new RecordedLogEvent(event));
        }
    };
    appender.start();
    final LoggerContext ctx = getLoggerContext();
    LoggerConfig loggerConfig = ctx.getConfiguration().getLoggerConfig(loggerClass.getName());
    oldLevel = loggerConfig.getLevel();
    loggerConfig.setLevel(level);
    loggerConfig.addAppender(appender, level, null);
    ctx.updateLoggers();
}
 

public static void configureLogger() {
    LoggerContext context = (LoggerContext) LogManager.getContext(false);
    Configuration config = context.getConfiguration();

    Map<String, ESLogger> loggers = Maps.newConcurrentHashMap();
    Appender appender = new AbstractAppender("", null, null) {
        @Override
        public void append(LogEvent event) {
            String name = event.getLoggerName();
            ESLogger logger = loggers.computeIfAbsent(name, key -> new ESLogger(key, null, (LoggerImpl) LoggerFactory.getLogger(key)));
            logger.log(event.getLevel(), event.getMarker(), event.getMessage(), event.getThrown());
        }
    };
    appender.start();
    config.addAppender(appender);

    var loggerConfig = new LoggerConfig("", Level.INFO, false); // only enable info and higher level
    loggerConfig.addAppender(appender, null, null);
    config.addLogger("", loggerConfig);
    context.updateLoggers();
}
 

/**
 * Gets an instance of the class.
 *
 * @param config  The current Configuration.
 * @param options pattern options, an array of two elements: pattern, max length (defaults to 100 on invalid value).
 * @return instance of class.
 */
public static MaxLengthConverter newInstance(final Configuration config, final String[] options) {
    if (options.length != 2) {
        LOGGER.error("Incorrect number of options on maxLength: expected 2 received {}: {}", options.length,
            options);
        return null;
    }
    if (options[0] == null) {
        LOGGER.error("No pattern supplied on maxLength");
        return null;
    }
    if (options[1] == null) {
        LOGGER.error("No length supplied on maxLength");
        return null;
    }
    final PatternParser parser = PatternLayout.createPatternParser(config);
    final List<PatternFormatter> formatters = parser.parse(options[0]);
    return new MaxLengthConverter(formatters, AbstractAppender.parseInt(options[1], 100));
}
 

@Override
protected void before() throws Throwable {
	loggingEvents = new ConcurrentLinkedQueue<>();

	Appender testAppender = new AbstractAppender("test-appender", null, null, false) {
		@Override
		public void append(LogEvent event) {
			loggingEvents.add(event.getMessage().getFormattedMessage());
		}
	};
	testAppender.start();

	AppenderRef appenderRef = AppenderRef.createAppenderRef(testAppender.getName(), null, null);
	LoggerConfig logger = LoggerConfig.createLogger(
		false,
		Level.getLevel(level.name()),
		"test",
		null,
		new AppenderRef[]{appenderRef},
		null,
		LOGGER_CONTEXT.getConfiguration(),
		null);
	logger.addAppender(testAppender, null, null);

	LOGGER_CONTEXT.getConfiguration().addLogger(loggerName, logger);
	LOGGER_CONTEXT.updateLoggers();
}
 

/**
 * Create a SmtpAppender.
 * @deprecated Use {@link #newBuilder()} to create and configure a {@link Builder} instance.
 * @see Builder
 */
public static SmtpAppender createAppender(final Configuration config, final String name, final String to,
                                          final String cc, final String bcc, final String from,
                                          final String replyTo, final String subject, final String smtpProtocol,
                                          final String smtpHost, final String smtpPortStr,
                                          final String smtpUsername, final String smtpPassword,
                                          final String smtpDebug, final String bufferSizeStr,
                                          Layout<? extends Serializable> layout, Filter filter,
                                          final String ignore) {
    if (name == null) {
        LOGGER.error("No name provided for SmtpAppender");
        return null;
    }

    final boolean ignoreExceptions = Booleans.parseBoolean(ignore, true);
    final int smtpPort = AbstractAppender.parseInt(smtpPortStr, 0);
    final boolean isSmtpDebug = Boolean.parseBoolean(smtpDebug);
    final int bufferSize = bufferSizeStr == null ? DEFAULT_BUFFER_SIZE : Integer.parseInt(bufferSizeStr);

    if (layout == null) {
        layout = HtmlLayout.createDefaultLayout();
    }
    if (filter == null) {
        filter = ThresholdFilter.createFilter(null, null, null);
    }
    final Configuration configuration = config != null ? config : new DefaultConfiguration();

    final SmtpManager manager = SmtpManager.getSmtpManager(configuration, to, cc, bcc, from, replyTo, subject, smtpProtocol,
        smtpHost, smtpPort, smtpUsername, smtpPassword, isSmtpDebug, filter.toString(),  bufferSize, null);
    if (manager == null) {
        return null;
    }

    return new SmtpAppender(name, filter, layout, ignoreExceptions, Property.EMPTY_ARRAY, manager);
}
 

@Override
public void start() {
    for (final AppenderRef ref : appenderRefs) {
        final String name = ref.getRef();
        final Appender appender = config.getAppender(name);
        if (appender != null) {
            final Filter filter = appender instanceof AbstractAppender ?
                ((AbstractAppender) appender).getFilter() : null;
            appenders.put(name, new AppenderControl(appender, ref.getLevel(), filter));
        } else {
            LOGGER.error("Appender " + ref + " cannot be located. Reference ignored");
        }
    }
    super.start();
}