InstrumentedLoggerSingleton

gistfile1.java

public class InstrumentedLoggerSingleton implements ConfigurationListener
{
	private static final Logger LOG = LoggerFactory.getLogger(InstrumentedLoggerSingleton.class);
	private static InstrumentedLoggerSingleton instance = null;
	
	private final InstrumentedAppender appender;
	private final Filter filter = null;
	private final PatternLayout layout = null;
	
	public static synchronized InstrumentedLoggerSingleton getInstance()
	{
		if (instance == null)
		{
			instance = new InstrumentedLoggerSingleton();			
		}
		
		return instance;
	}

	private InstrumentedLoggerSingleton()
	{
		appender = new InstrumentedAppender(MetricRegistrySingleton.getInstance().getMetricsRegistry(), filter, layout, false);
		appender.start();		
		instrument();
	}
	
	private void instrument()
	{
		LoggerContext context = (LoggerContext) LogManager.getContext(false);
		Configuration config = context.getConfiguration();

		config.getLoggerConfig(LogManager.ROOT_LOGGER_NAME).addAppender(appender, Level.ALL, filter);
		config.addListener(this);
		context.updateLoggers(config);		
		
		LOG.info("Logging configuration has been modified and a new InstrumentedAppender has been configured on the root logger");		
	}
	
	public void onChange(Reconfigurable reconfigurable)
	{
		instrument();
	}
}

log4j2 only, handy though...